Pengelolaan Hama Serangga Beras

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"So dependent upon rice are the Asian countries that throughout history a failure of that crop has caused widespread famine and death." "Jadi tergantung pada beras adalah negara-negara Asia yang sepanjang sejarah kegagalan panen yang menyebabkan kelaparan luas dan kematian."
Robert F. Chandler, Jr., 1979 Robert F. Chandler, Jr, 1979
Photograph: Deepwater rice in Thailand. Foto: Deepwater beras di Thailand.

Introduction Pengantar

On a global basis sufficient food is produced to adequately feed everyone. Pada basis global cukup makanan diproduksi untuk cukup memberi makan semua orang. Yet, the pains of hunger continue to be a common experience of many people in the world today. Namun, rasa sakit kelaparan terus menjadi pengalaman umum banyak orang di dunia saat ini. Food shortages in developing countries are aggravated by rapid population growth. kekurangan pangan di negara-negara berkembang diperparah oleh pertumbuhan penduduk yang cepat. In the last 40 years the increase in the world's population has equalled the increase that occurred from the emergence of the human race to the middle of the 20th century. Dalam 40 tahun terakhir peningkatan populasi dunia telah setara dengan peningkatan yang terjadi dari munculnya umat manusia ke tengah abad ke-20.
The desire for food security has adversely affected the environment. Keinginan untuk ketahanan pangan berdampak buruk terhadap lingkungan. Of additional concern is the evidence of a yield growth rate stagnation in countries where the "Green Revolution" has had its greatest impact. Dari perhatian tambahan adalah bukti dari stagnasi pertumbuhan produksi di negara-negara di mana "Revolusi Hijau" telah memiliki dampak terbesar. If recent growth rates for cereal demand continue to 2025, the food need in Sub-Saharan Africa will be 2.5 times greater than production. Jika tingkat pertumbuhan terbaru untuk permintaan sereal terus 2025, kebutuhan pangan di Sub-Sahara Afrika akan menjadi 2,5 kali lebih besar dari produksi. Among the major cereals, rice is the primary staple of more than two billion people in Asia and hundreds of millions of people in Africa and Latin America. Di antara sereal utama, beras merupakan pokok utama lebih dari dua miliar orang di Asia dan ratusan juta orang di Afrika dan Amerika Latin. Consumption per capita varies greatly from l86 kg/year in Burma to 4 kg/year in the USA. Konsumsi per kapita sangat bervariasi dari l86 kg / tahun di Burma untuk 4 kg / tahun di Amerika Serikat.
Today, rice is just as important to food security, or more so, than it was in 1979 when the first Director General of the International Rice Research Institute (IRRI), RF Chandler, made the above statement. Hari ini, beras adalah sama pentingnya untuk keamanan pangan, atau lebih dari itu, daripada pada tahun 1979 ketika pertama Direktur Jenderal International Rice Research Institute (IRRI), RF Chandler, membuat pernyataan di atas. To cope with the increasing demand for rice a key element is the development and implementation of effective rice insect management strategies. Untuk mengatasi meningkatnya permintaan beras elemen kunci adalah pengembangan dan pelaksanaan strategi pengelolaan padi serangga yang efektif. This lecture discusses the role of rice in food security and provides some background information on rice as to its taxonomic classification, origin and spread, growth stages, geographical distribution and production systems. kuliah ini membahas peran beras dalam keamanan pangan dan menyediakan beberapa informasi latar belakang beras untuk klasifikasi taksonomi nya, asal dan menyebar, tahap pertumbuhan, distribusi geografis dan sistem produksi. This is followed by a discussion of the damage caused by rice insects and their management strategies. Hal ini diikuti dengan diskusi tentang kerusakan yang disebabkan oleh serangga beras dan strategi manajemen mereka.

Classification of Rice Klasifikasi Beras

Rice, an annual grass (Gramineae), belongs to the genus Oryza which includes twenty wild species and two cultivated species, O. sativa (Asian rice) and O. glaberrima African rice). Padi, sebuah rumput tahunan (Gramineae), termasuk dalam genus Oryza yang mencakup dua puluh spesies liar dan dua spesies budidaya, O. sativa (beras Asia) dan O. glaberrima Afrika beras). Oryza sativa is the most commonly grown species throughout the world today. Oryza sativa merupakan spesies yang paling sering ditanam di seluruh dunia saat ini. In Asia O. sativa is differentiated into three subspecies based on geographic conditions; indica, javanica, and japonica. Di Asia O. sativa dibedakan menjadi tiga subspesies yang didasarkan pada kondisi geografis; indica, javanica, dan japonica. Indica refers to the tropical and subtropical varieties grown throughout South and Southeast Asia and southern China. Indica mengacu pada varietas tropis dan subtropis tumbuh di seluruh Asia Selatan dan Tenggara dan Cina selatan. Javanica designates the bulu (awned) and gundil (awnless) rices with long panicles and bold grains growing alongside of indicas in Indonesia. Javanica menunjuk pada bulu (awned) dan gundil (awnless) padi dengan panjang malai dan biji-bijian berani tumbuh bersama dari indicas di Indonesia. Japonica refers to the short and roundish grained varieties of the temperate zones of Japan, China, and Korea. Japonica mengacu pada varietas berbutir pendek dan agak bulat dari zona beriklim Jepang, Cina, dan Korea. Japonica-type varieties are grown in northern California, USA due to their tolerance to low night temperatures. Japonica-jenis varietas yang tumbuh di California utara, Amerika Serikat karena toleransi mereka untuk suhu malam hari rendah. Indica-type varieties are grown in the southern USA. Indica-jenis varietas yang ditanam di Amerika Serikat selatan.

Origin and Spread of Rice Asal dan Penyebaran Beras

Domestication of O. sativa occurred some l0,000 years ago in the river valleys of South and Southeast Asia and China. O. sativa domestikasi terjadi beberapa l0, 000 tahun yang lalu di lembah sungai Selatan dan Asia Tenggara dan Cina. Rice specimens found in China date back to 3,000 BC and earliest historical Chinese writings indicate that of the five principal food plants in the country, rice was the most important. Beras spesimen ditemukan di Cina tanggal kembali ke 3000 SM dan paling awal tulisan Cina historis menunjukkan bahwa dari lima tanaman pangan utama di negeri ini, beras adalah yang paling penting.
Rice was introduced into southern Japan from China in about l00 BC and from there it spread reaching the extreme north of Japan only in the eighteenth century. Rice diperkenalkan ke Jepang selatan dari Cina sekitar l00 SM dan dari sana menyebar mencapai ujung utara Jepang hanya pada abad kedelapan belas. The Portuguese introduced rice into Brazil and the Spaniards introduced rice into Central America and parts of South America. Portugis memperkenalkan beras ke Brazil dan Spanyol memperkenalkan beras ke Amerika Tengah dan bagian dari Amerika Selatan.
Rice cultivation in the USA dates from about l646 when it was introduced into the James River region of Virginia and in l685 when it was first grown in the colony of South Carolina. Pertanian padi di USA tanggal dari sekitar l646 ketika diperkenalkan ke dalam wilayah Sungai James dari Virginia dan di l685 ketika pertama kali ditanam di koloni South Carolina. The rice variety, "Carolina Gold" was introduced into South Carolina when a storm forced a New England ship, sailing from Madagascar, to harbor in Charleston. Varietas padi, "Carolina Gold" diperkenalkan ke South Carolina saat badai memaksa sebuah kapal New England, berlayar dari Madagaskar, ke pelabuhan di Charleston. Before leaving the port, the captain gave the colonists about 5 kg of rice seed and that started the Carolina rice industry. Sebelum meninggalkan pelabuhan, sang kapten memberikan koloni sekitar 5 kg benih padi dan yang memulai industri padi Carolina. Rice was introduced into Louisiana in 1718 but did not assume importance there until l887. Rice diperkenalkan ke Louisiana di 1718 tapi tidak menganggap penting di sana sampai l887. Commercial rice production in the Sacramento Valley, California began in 1912. produksi beras komersial di Lembah Sacramento, California mulai tahun 1912.

The Rice Plant Plant Rice

The parts of a mature rice plant are illustrated in Figure 1. Bagian-bagian dari tanaman padi dewasa diilustrasikan dalam Gambar 1. The rice plant consists of the roots, stem, leaves and panicle. Tanaman padi terdiri dari akar, batang, daun dan malai. Rice passes through the following l0 stages during its growth cycle: (l) germination and emergence, (2) seedling, (3) tillering, (4) stem elongation, (5) panicle initiation, (6) panicle development, (7) flowering, (8) milk grain, (9) dough grain, and (l0) mature grain stage. Beras melewati tahapan berikut l0 selama siklus pertumbuhannya: (l) perkecambahan dan munculnya, (2) bibit, (3) anakan, (4) batang perpanjangan, (5) inisiasi malai, (6) pengembangan malai, (7) berbunga, (8) butir susu, (9) adonan gandum, dan (l0) tahap butir dewasa. Traditional varieties require about l50 days of growth to reach the mature grain stage whereas the modern, high yielding, very early maturing varieties can be harvested in as few as 90 days after sowing. varietas tradisional membutuhkan sekitar l50 hari pertumbuhan untuk mencapai tahap gandum dewasa sedangkan modern, unggul, varietas jatuh tempo sangat awal dapat dipanen dalam sedikitnya 90 hari setelah tanam.
Figure 1. Mature rice plant. Gambar 1. Tanaman tanaman padi.

Where is Rice Grown? Dimana Rice Grown?

Rice is cultivated from 53° N to 40° S latitude where it is adapted to a wide range of environmental conditions, from uplands to waterlogged lowlands. Beras dibudidayakan dari 53 ° N sampai 40 ° garis lintang S mana disesuaikan dengan berbagai kondisi lingkungan, dari dataran tinggi ke dataran rendah terendam air. It is grown at high elevations, such as the rice terraces in the mountains in the Philippines (Figure 2), and at low elevations down to sea level. Hal ini tumbuh pada ketinggian tinggi, seperti sawah di pegunungan di Filipina (Gambar 2), dan pada ketinggian rendah sampai ke permukaan laut.
Figure 2. Rice growing on mountain terraces in the Philippines. Gambar 2. Beras tumbuh di teras gunung di Filipina.

Table 1. Rice area, production and yield by world region (FAOSTAT-PC, FAO 1995). Tabel 1. Beras wilayah, produksi dan hasil menurut wilayah dunia (FAOSTAT-PC, FAO 1995).
Region Daerah	Area harvested (000 ha) Luas panen (000 ha)	Production(000 metric ton) Produksi (000 ton metrik)	Grain yield/ha(metric ton) Hasil gabah / ha (ton metrik)
South America Amerika Selatan	5,659 5,659	15,295 15,295	2.70 2.70
USA Amerika Serikat	1,336 1,336	8,972 8,972	6.72 6.72
Central America Amerika Tengah	552 552	1,929 1,929	3.49 3.49
Europe Eropa	378 378	2,113 2,113	5.59 5.59
Asia Asia	130,027 130,027	485,077 485,077	3.73 3.73
Africa Afrika	7,235 7,235	15,855 15,855	2.19 2.19
World Dunia	1,456,187 1,456,187	529,241 529,241

Rice Production Systems Sistem Produksi Beras

There are two major systems of rice cultivation; the dry or upland system, in which the crop is grown on dry ground, the same as for wheat and other cereals; and the wet system, in which the rice land is flooded and the crop is grown in standing water from planting until near harvesting. Ada dua sistem utama budidaya padi; sistem kering atau lahan kering, di mana tanaman yang tumbuh di tanah yang kering, sama seperti untuk gandum dan sereal lainnya, dan sistem basah, di mana tanah sawah kebanjiran dan tanaman ini tumbuh di berdiri air dari penanaman sampai panen dekat. Rice production systems more specifically classified according to ecology in terms of water are (1) upland, (2) irrigated, (3) rainfed lowland, and (4) deep water. sistem produksi padi lebih spesifik diklasifikasikan menurut ekologi dalam hal air adalah (1) dataran tinggi, (2) irigasi, (3) sawah tadah hujan, dan (4) air yang dalam.
Upland rice is often grown in hilly areas (Figure 3) with natural rainfall and without levees to impound water. Padi gogo sering ditanam di daerah perbukitan (Gambar 3) dengan curah hujan alami dan tanpa tanggul untuk menyita air. An assured rainfall over a 3 to 4 month period is necessary as the crop is rainfed and the water supply is not controlled. Sebuah curah hujan meyakinkan selama periode 3 sampai 4 bulan diperlukan karena tanaman ini tadah hujan dan pasokan air tidak terkontrol.
Figure 3. Upland rice growing on rocky soil in the forest region of Côte d'Ivoire, West Africa. Gambar 3. Upland padi tumbuh di tanah berbatu di kawasan hutan Pantai Gading, Afrika Barat.
In the forest region of West Africa, prior to sowing of rice, trees, shrubs and weeds in fallow upland fields are cut and then burned. Di wilayah hutan Afrika Barat, sebelum menabur beras, pohon, semak dan gulma di lahan tegalan bera dipotong dan kemudian dibakar. For rice plants to compete with weeds, rice seed is sown within a few days after burning. Untuk tanaman padi bersaing dengan gulma, biji padi disebarkan dalam beberapa hari setelah pembakaran. Seed is sown directly into untilled land with the aid of a hand hoe (Figure 4). Benih disebarkan secara langsung ke tanah untilled dengan bantuan sebuah cangkul tangan (Gambar 4).
Figure 4. Upland rice being sown with the aid of a hand hoe in a recently burned field in the forest region of southern Côte d'Ivoire, West Africa. Gambar 4. Upland padi yang ditanam dengan bantuan sebuah cangkul tangan di lapangan terbakar baru-baru ini di wilayah hutan selatan Pantai Gading, Afrika Barat. Rice seeds are in the coke bottle. biji padi dalam botol coke.
Irrigated rice is grown in fields with levees to impound water supplied principally from irrigation. Irigasi padi ditanam di bidang dengan tanggul untuk menyita air dipasok terutama dari irigasi. Water control is more accurate than with rainfed rice and seldom exceeds 50 cm. Air kontrol lebih akurat dibandingkan dengan sawah tadah hujan dan jarang melebihi 50 cm. Rainfed lowland rice is grown in standing water in fields with levees to impound natural rainfall. Padi sawah tadah hujan ditanam dalam air berdiri di bidang dengan tanggul untuk menyita curah hujan alami. If rainfall is heavy, water may reach depths of 50 to 100 cm. Jika curah hujan lebat, air dapat mencapai kedalaman 50 sampai 100 cm. Deep water rice is grown in the flood plains along rivers in Mali in West Africa, and India, Bangladesh and Thailand (Figure 5) in Asia. air beras Deep ditanam di dataran banjir di sepanjang sungai di Mali di Afrika Barat, dan India, Bangladesh dan Thailand (Gambar 5) di Asia. Water depth may reach several meters during monsoon rains and varieties adapted to deepwater conditions can elongate at the rate of 25 cm per day in rapidly rising water. kedalaman air dapat mencapai beberapa meter selama musim hujan dan varietas disesuaikan dengan kondisi perairan dapat memanjang sebesar 25 cm per hari dalam air cepat naik.
Figure 5. Deepwater rice in Thailand. Gambar 5. Deepwater beras di Thailand.
Irrigated, rainfed lowland (Figure 6) and deepwater rice fields are ploughed when the rainy season begins and puddled to provide a fine tilth before flooding. Irigasi, sawah tadah hujan (Gambar 6) dan sawah laut yang dibajak ketika musim hujan mulai dan menggenang untuk memberikan hasil panen baik sebelum banjir. Seed may be either broadcast or drilled into the soil or it may be sown in nursery beds and the seedlings subsequently transplanted when they reach a suitable stage of growth (about 21 days after sowing). Benih dapat berupa siaran atau di bor ke dalam tanah atau mungkin ditanam di tempat tidur pembibitan dan bibit kemudian ditransplantasi ketika mereka mencapai tahap sesuai pertumbuhan (sekitar 21 hari setelah tanam). Rice in the USA is pregerminated and broadcast into irrigated rice fields from airplanes or drill-seeded. Beras di Amerika Serikat adalah pra-kecambahkan dulu dan disiarkan ke sawah beririgasi dari pesawat atau bor-unggulan.
Figure 6. Rainfed lowland rice field in Togo, West Africa being tilled by hand prior to transplanting. Gambar 6. Sawah tadah hujan sawah di Togo, Afrika Barat yang digarap dengan tangan sebelum tanam. A rice crop in the vegetative stage (panicle initiation) is seen in the background. Sebuah tanaman padi di tahap vegetatif (inisiasi malai) terlihat di latar belakang.
Most of the rice area in China (Figure 7) and the USA is irrigated. Sebagian besar lahan sawah di Cina (Gambar 7) dan USA adalah irigasi. In Latin America and Africa most of the rice is upland. Di Amerika Latin dan Afrika sebagian besar padi adalah dataran tinggi.
Figure 7. Irrigated rice being harvested by hand in China. Gambar 7. Irigasi beras yang dipanen dengan tangan di Cina.

Plant Damage Caused by Rice Insects Kerusakan Tanaman Padi Akibat Serangga

Insect pests attack all portions of the rice plant and all stages of plant growth. Serangga hama menyerang semua bagian dari tanaman padi dan semua tahap pertumbuhan tanaman. Feeding guilds consist of the (1) root feeders, (2) stem borers, (3) leafhoppers and planthoppers, (4) defoliators, and (5) grain sucking insects. serikat makan terdiri dari (1) feeder root, (2) penggerek batang, (3) wereng dan wereng, (4) defoliators, dan serangga butir (5) mengisap. Insects also attack rice grains in storage. Serangga juga menyerang biji beras dalam penyimpanan.
Root Feeders Root Feeders
Examples of root feeders are termites (order Isoptera) and the rice water weevil, Lissorhoptrus oryzophilus (order Coleoptera). Contoh pengumpan akar rayap (urutan Isoptera) dan kumbang air beras, oryzophilus Lissorhoptrus (ordo Coleoptera). Termites, in West African upland rice fields, occur in patches and often kill the plants, especially when rainfall is lacking. Rayap, di ladang padi gogo Afrika Barat, terjadi pada patch dan sering membunuh tanaman, terutama ketika curah hujan kurang. The water weevil is a major insect pest of irrigated rice in the USA. The bonggol air adalah serangga hama utama beras irigasi di Amerika Serikat. The adult water weevil feeds on the leaves and causes little damage while the larvae feed on the roots and severely reduce the root system. The bonggol air dewasa feed pada daun dan menyebabkan kerusakan kecil sedangkan pakan larva pada akar dan sangat mengurangi sistem akar. Plants with reduced root systems grow poorly and have low yields. Tanaman dengan sistem akar mengurangi tumbuh buruk dan memiliki hasil yang rendah.
Stem Borers Penggerek batang
Stem borers consist primarily of insects in the lepidopterous families, Noctuidae and Pyralidae. penggerek Batang terutama terdiri dari serangga di keluarga lepidopterous, Noctuidae dan Pyralidae. The adult moths lay eggs on rice leaves and the larvae bore into the stem. Ngengat dewasa bertelur pada daun padi dan larva membosankan ke dalam batang. Feeding in the stem during the vegetative growth stage of the plant (seedling to stem elongation) causes death of the central shoot ("deadheart"). Makan di batang selama tahap pertumbuhan vegetatif tanaman (bibit untuk membendung elongasi) menyebabkan kematian tunas pusat ("deadheart"). Damaged shoots do not produce a panicle, and thus, produce no grain. tunas Rusak tidak menghasilkan malai, dan dengan demikian, menghasilkan biji-bijian tidak. Feeding of stem borers during the reproductive stage (panicle initiation to milk grain) causes a severing of the developing panicle at its base. Makan penggerek batang selama tahap reproduksi (inisiasi malai terhadap susu gandum) menyebabkan memutuskan dari malai berkembang pada dasarnya. As a result, the panicle is unfilled and whitish in color, rather than filled with grain and brownish in color. Akibatnya, malai yang terisi dan keputihan dalam warna, daripada diisi dengan gandum dan kecoklatan. Such empty panicles are called "whiteheads". malai kosong seperti ini disebut "whitehead". In the southern USA the sugarcane borer, Diatraea saccharalis , and the rice stalk borer, Chilo plejadellus are common stem borers attacking rice. Di Amerika Serikat yang penggerek tebu selatan, saccharalis Diatraea, dan penggerek batang padi, plejadellus adalah penggerek batang Chilo umum menyerang padi.
Leafhoppers and Planthoppers Wereng dan wereng
In general, the leafhoppers (family Cicadellidae) attack all aerial parts of the plant whereas the planthoppers (family Delphacidae) attack the basal portions (stems). Secara umum, wereng (keluarga Cicadellidae) serangan udara semua bagian tanaman sedangkan wereng (keluarga Delphacidae) menyerang bagian basal (batang).
Figure 8. The brown planthopper, an important pest of rice in Asia. Gambar 8,. Cokelat wereng hama penting padi di Asia.
The leafhoppers and planthoppers (order Hemiptera) are sucking insects which remove plant sap from the xylem and phloem tissues of the plant. Para wereng dan wereng (order Hemiptera) yang mengisap serangga yang menghilangkan getah tanaman dari jaringan xilem dan floem tanaman. Severely damaged plants dry and take on the brownish appearance of plants that have been damaged by fire. rusak parah tanaman kering dan mengambil bentuk kecoklatan tanaman yang telah rusak akibat kebakaran. Hence, hopper damage is called "hopper burn". Oleh karena itu, kerusakan gerbong disebut "hopper membakar". These insects are severe pests in Asia (Figure 8) where they not only cause direct damage, by removing plant sap, but are also vectors of serious rice virus diseases, such as rice tungro virus transmitted by the green leafhopper, Nephotettix virescens , and grassy stunt virus transmitted by the brown planthopper, Nilaparvata lugens . Ini serangga merupakan hama yang parah di Asia (Gambar 8) di mana mereka tidak hanya menyebabkan kerusakan langsung, dengan menghapus tanaman getah, tetapi juga vektor penyakit virus beras serius, seperti virus tungro padi ditularkan oleh wereng hijau, virescens Nephotettix, dan rumput aksi virus ditularkan oleh wereng coklat, Nilaparvata lugens.
Defoliators Defoliators
A large group of insects belonging to several insect orders feed on rice leaves. Sekelompok besar serangga milik beberapa pesanan makan serangga pada daun padi. Most common are the larvae and adults of beetles (order Coleoptera), larvae of the order Lepidoptera and grasshoppers (order Orthoptera). Paling umum adalah larva dan dewasa kumbang (ordo Coleoptera), larva dari order Lepidoptera dan belalang (Orthoptera order). Defoliation reduces the photosynthetic capacity of the rice plant and thereby decreases yields. Defoliasi mengurangi kapasitas fotosintesis tanaman padi dan dengan demikian menurunkan hasil. However, when feeding damage occurs early in rice growth, plants have an ability to compensate for damage by producing new tillers. Namun, ketika kerusakan makan terjadi pada awal pertumbuhan padi, tanaman memiliki kemampuan untuk mengkompensasi kerusakan dengan menghasilkan anakan baru. Thus, rice plants in the actively tillering stage of growth can tolerate a certain level of leaf damage without any yield loss. Dengan demikian, tanaman padi dalam tahap anakan aktif pertumbuhan dapat mentolerir tingkat tertentu kerusakan daun tanpa kehilangan hasil. An example of a coleopterous defoliator, is the adult of the rice water weevil in the USA. Contoh dari defoliator coleopterous, adalah orang dewasa dari kumbang air beras di Amerika Serikat. Foliage removal by this beetle, however, is usually minimal and below the yield reducing level. penghapusan Daun oleh kumbang ini, bagaimanapun, biasanya minimal dan di bawah tingkat hasil mengurangi. The common armyworm, Pseudaletia unipuncta (order Lepidoptera) occurs sporadically in epidemic numbers on rice in California where leaf feeding by the larvae causes yield reductions. The ulat grayak umum, Pseudaletia unipuncta (order Lepidoptera) terjadi secara sporadis dalam jumlah epidemi beras di California di mana makan daun oleh larva penyebab penurunan hasil.
Grain Sucking Insects Grain Menyedot Serangga
The stink bugs (order Hemiptera), known for the foul odor produced by the scent glands on their abdomen, penetrate the developing grain with their sucking mouthparts and remove the white fluid referred to as "milk". Bau busuk bug (order Hemiptera), dikenal karena bau busuk yang dihasilkan oleh kelenjar bau pada perut mereka, menembus butiran berkembang dengan mulut menghisap dan mengeluarkan cairan putih disebut sebagai "susu". Damage early in the development of the grain prevents the filling of the grain. Kerusakan awal dalam pengembangan gandum mencegah pengisian gandum. Later attack results in "pecky rice" which is referred to as the condition of the grain after being sucked by stink bugs and the grain being subsequently stained by the bacteria or fungi which enter the puncture wounds. Kemudian serangan menghasilkan "beras pecky" yang disebut sebagai kondisi gandum setelah tersedot oleh bau bug dan gandum yang kemudian ternoda oleh bakteri atau jamur yang masuk luka-luka tusukan. In some countries the market price of pecky rice is reduced. Di beberapa negara harga pasar beras pecky berkurang. The stink bug, Oebalus pugnax, found in North America east of the Rocky Mountains and as far north as Minnesota, is a pest of rice in the southern USA. Bau busuk bug, pugnax Oebalus, ditemukan di Amerika Utara timur Pegunungan Rocky dan sejauh utara Minnesota, merupakan hama beras di Amerika Serikat selatan.

Yield Losses Caused by Rice Insect Pests Hasil Kerugian Akibat Hama Serangga Rice

Historical records from Korea and Japan report on the history of rice insect pests during the last two millennia. Sejarah catatan dari Korea dan Jepang pada laporan sejarah hama serangga beras selama dua ribu tahun terakhir. In 875 a migratory locust outbreak occurred in the Ise District of Japan and a brown planthopper outbreak in l733 was reported as one of the most damaging insect outbreaks in the history of rice production in Japan. Dalam 875 sebuah wabah belalang migrasi terjadi di Kabupaten Ise dari Jepang dan wabah wereng coklat l733 dilaporkan sebagai salah satu dari wabah serangga yang paling merusak dalam sejarah produksi padi di Jepang. About 2.6 million persons were affected and l2,000 died from hunger. Sekitar 2,6 juta orang terkena dampak dan l2, 000 meninggal karena kelaparan.
Insects reduce yields substantially, especially in tropical Asia. Serangga mengurangi hasil secara substansial, terutama di Asia tropis. Cramer estimated the rice yield losses caused by insects by reviewing the literature up to l966 (Table 2). Cramer memperkirakan kehilangan hasil padi yang disebabkan oleh serangga dengan meninjau literatur hingga l966 (Tabel 2). He estimated losses ranging from 31.5% in Asia to 2% in Europe. Dia memperkirakan kerugian berkisar antara 31,5% di Asia menjadi 2% di Eropa. More recently, a series of experiments coordinated by IRRI and conducted in farmers' fields in six Asian countries indicated that the increase in yields of fields receiving fertilizer, and insect and weed control was 0.9 t/ha in the wet season and l.7 t/ha in the dry season; 0.4 ton and 0.6 ton of these yield increases respectively, were due to insect control. Baru-baru ini, serangkaian percobaan yang dikoordinasikan oleh IRRI dan dilakukan di bidang petani di enam negara Asia menunjukkan bahwa peningkatan hasil bidang menerima pupuk, dan penanggulangan hama dan gulma adalah 0,9 t / ha pada musim hujan dan l.7 t / ha pada musim kering; 0,4 ton dan 0,6 ton dari kenaikan hasil masing-masing, adalah karena serangga kontrol. The importance of insects and other pests is indicated by the fact that only a 10% increase or decrease in food grain production, on a global scale, can make the difference between a glut and acute scarcity. Pentingnya serangga dan hama lain adalah ditunjukkan oleh fakta bahwa hanya meningkat 10% atau penurunan produksi pangan biji-bijian, pada skala global, bisa membuat perbedaan antara kekenyangan dan kelangkaan akut.

Table 2. Estimated rice yield losses caused by Tabel 2. Hasil padi Estimasi kerugian yang disebabkan oleh insect pests on a world basis (from Cramer 1967) hama serangga secara dunia (dari Cramer 1967)
Region Daerah	Yield loss (%) Kehilangan hasil (%)
Asia Asia	31.5 31.5
People's Republic of China Republik Rakyat Cina	15.0 15.0
Africa Afrika	14.4 14.4
South America Amerika Selatan	3.5 3.5
North and Central America Utara dan Amerika Tengah	3.4 3.4
Europe Eropa	2.0 2.0

Factors Affecting Extent of Insect-Caused Yield Losses in Rice Faktor yang Mempengaruhi Tingkat Kerugian Akibat Serangga-Rata dalam Rice

Although rice insects have been a problem through the centuries, outbreaks have increased and the insect pest complex has changed, in the last four decades. Meskipun serangga padi menjadi masalah selama berabad-abad, wabah telah meningkat dan kompleks hama serangga telah berubah, dalam empat dekade terakhir. Some insects have increased in severity, whereas others have declined in importance. Beberapa serangga telah meningkat di keparahan, sedangkan yang lain telah menurun penting. There is evidence that ecologically specialized (monophagous) species have been favored by crop intensification. Ada bukti bahwa ekologis khusus (monophagous) spesies telah disukai oleh intensifikasi tanaman. Intensification involves changes in cultural practices such as (1) an increase in the number of crops grown per year, (2) an increase in the use of agricultural chemicals (fertilizer and pesticides), (3) increased area under irrigation, and (4) increased plant densities. Intensifikasi melibatkan perubahan dalam praktek-praktek budaya seperti (1) peningkatan jumlah tanaman tumbuh per tahun, (2) peningkatan dalam penggunaan bahan kimia pertanian (pupuk dan pestisida), (3) meningkatkan area di bawah irigasi, dan (4 ) meningkat kepadatan tanaman.
Changes in rice cultural practices have accompanied the widespread adoption of modern varieties. Perubahan dalam praktek padi budaya telah menemani luas adopsi varietas modern. The photoperiod insensitivity and reduced growth duration of the modern varieties have made it possible to grow two and even three crops per year, where water, and temperatures are adequate. Ketidakpekaan fotoperiodik dan durasi mengurangi pertumbuhan varietas modern telah memungkinkan untuk tumbuh dua dan bahkan tiga tanaman per tahun, dimana air, dan temperatur yang memadai. Continuous cropping throughout the year has caused shifts in the composition of pest fauna. Continuous tanam sepanjang tahun telah menyebabkan pergeseran dalam komposisi fauna hama. Species dependent on standing water, such as the whorl maggot, Hydrellia philippina, and the rice caseworm Nymphula depunctalis, have become more abundant because of increased area under irrigation. Spesies tergantung pada berdiri air, seperti belatung whorl, Filipina Hydrellia, dan beras caseworm Nymphula depunctalis, telah menjadi lebih berlimpah karena daerah meningkat di bawah irigasi.
The most dramatic effects of modern cultural practices on abundance of rice insect specialists in Asia is seen in the plant sucking Homoptera, especially the nearly monophagous brown planthopper. Efek yang paling dramatis praktek-praktek budaya modern pada kelimpahan spesialis serangga beras di Asia dilihat di pabrik mengisap Homoptera, terutama wereng coklat hampir monophagous. The brown planthopper (Figure 8) arose from the status of a secondary pest to a major yield constraint beginning in the l960s. The wereng coklat (Gambar 8) berasal dari status hama sekunder merupakan kendala utama hasil awal di l960s. The increased use of resurgence-inducing insecticides, has been considered the major cause of intensified brown planthopper problems. Peningkatan penggunaan insektisida kebangkitan-merangsang, telah dianggap sebagai penyebab utama intensif masalah wereng coklat. Resurgence-inducing insecticides are selectively toxic to the predators of the brown planthopper and result in a dramatic population increase of the brown planthopper after insecticide application. Kebangkitan-inducing insektisida selektif racun bagi predator dari wereng coklat dan menghasilkan peningkatan dramatis dari populasi wereng coklat setelah aplikasi insektisida.

Development of Pest Management Tactics for Rice Pengembangan Taktik Pengendalian Hama Tanaman Padi

As rice scientists and farmers have gained experience in the cultivation of the modern varieties and the agronomic practices that have accompanied the "Green Revolution" there has been a shift from a primarily unilateral approach of insect control, with a strong reliance on insecticides, to a multilateral approach involving a mix of control tactics. Seperti beras ilmuwan dan petani telah memperoleh pengalaman dalam budidaya varietas modern dan praktek-praktek agronomi yang telah menemani "Revolusi Hijau" telah terjadi pergeseran dari pendekatan terutama sepihak kontrol serangga, dengan ketergantungan yang kuat pada insektisida, ke pendekatan multilateral yang melibatkan campuran taktik kontrol. This approach, known as integrated pest management (IPM), in the simplest terms is referred to as "a broad ecological attack combining several tactics including biological, chemical, and cultural control methods and insect resistant rice varieties, for the economic control and management of pest populations". Pendekatan ini, yang dikenal sebagai manajemen hama terpadu (PHT), dalam istilah sederhana disebut sebagai "serangan ekologi yang luas menggabungkan beberapa taktik termasuk biologi, kimia, dan budaya kontrol metode dan serangga varietas padi tahan, untuk kontrol ekonomi dan manajemen populasi hama ".
IPM programs have a significant impact on minimizing the adverse effects of insecticides, and in increasing the profitability of rice production. program IPM memiliki dampak yang signifikan terhadap meminimalkan dampak merugikan dari insektisida, dan dalam meningkatkan profitabilitas produksi beras. It has been estimated that the cost savings from research leading to increased insect pest management efficiency on rice in South and Southeast Asia will be $973 million in insecticide saved by the year 2,000. Telah diperkirakan bahwa penghematan biaya dari penelitian yang mengarah ke peningkatan efisiensi pengelolaan serangga hama di beras di Asia Selatan dan Tenggara akan menjadi $ 973,000,000 di insektisida diselamatkan oleh 2.000 tahun.
During a 1960s visit to IRRI in the Philippines Norman Cousins, then editor of the Saturday Review, wrote that "any genuine improvement in the human condition on this planet must be concerned with rice." Selama kunjungan tahun 1960 ke IRRI di Filipina Norman Cousins, maka editor dari Saturday Review, menulis bahwa "perbaikan asli dalam kondisi manusia di planet ini harus peduli dengan beras." Scientists throughout the rice growing regions of the world are striving to do their part in improving the quality of life by developing and implementing strategies to more effectively and economically manage rice insect pests. Para ilmuwan di seluruh menanam padi wilayah dunia berjuang untuk melakukan bagian mereka dalam meningkatkan kualitas hidup dengan mengembangkan dan menerapkan strategi untuk lebih efektif dan ekonomis padi mengelola hama serangga. These strategies will now be discussed. Strategi ini sekarang akan dibahas.

Cultural Practices Budaya Praktik

Cultural methods to control insects involve crop production practices that have a dual purpose of crop production and insect suppression. metode Budaya untuk mengendalikan serangga melibatkan praktek produksi tanaman yang memiliki tujuan ganda produksi tanaman dan penindasan serangga. Farmers have developed these practices through many years of trial and error and these practices have been handed down through generations. Petani telah mengembangkan praktek-praktek melalui bertahun-tahun trial and error dan praktek-praktek ini telah diwariskan dari generasi ke generasi. Primary cultural control practices are those done specifically to control insects such as draining a field to control the aquatic caseworm larva or planting a trap crop for stem borers. Primer praktek kontrol budaya adalah yang dilakukan untuk mengendalikan serangga khusus seperti pengeringan lapangan untuk mengontrol larva caseworm air atau menanam tanaman perangkap untuk penggerek batang. Secondary practices are those that are specifically done for crop husbandry, such as land preparation and weeding, but which also happen to minimize pest buildup. praktik sekunder adalah mereka yang secara khusus dilakukan untuk peternakan tanaman, seperti persiapan lahan dan penyiangan, tetapi yang juga terjadi untuk meminimalkan penumpukan hama.
Rice culture has a rich source of folklore regarding indigenous cultural practices. Rice budaya memiliki sumber yang kaya cerita rakyat mengenai praktek-praktek budaya masyarakat adat. Cultural control practices that offer potential control of rice insects includes (1) mixed cropping, (2) planting methods (transplanting vs direct seeding), (3) age of seedlings at time of transplanting, (4) water management, (5) fertilizer management, (6) crop rotation, (7) number of rice crops per year, (8) planting time, (9) synchronous vs asynchronous planting over a given area, (10) trap crop, (11) tillage, (12) weeding and (13) growth duration of the crop. praktek kontrol Budaya yang menawarkan potensi pengendalian serangga padi meliputi (1) pertanian campuran, metode penanaman (2) (tanam pembenihan langsung vs), (3) umur bibit pada saat tanam, (4) pengelolaan air, (5) pupuk manajemen, (6) rotasi tanaman, (7) jumlah tanaman padi per tahun, (8) waktu tanam, (9) sinkron vs asinkron tanam di daerah tertentu, (10) tanaman perangkap, (11) persiapan lahan, (12) penyiangan dan (13) durasi pertumbuhan tanaman.

Chemical Control Pengendalian kimia

When modern rice varieties were introduced in the 1960's, insecticides were one component in a package of technologies of the "Green Revolution" in Asia. Ketika varietas padi modern diperkenalkan pada 1960-an, insektisida adalah satu komponen dalam paket teknologi dari "Revolusi Hijau" di Asia. Chlorinated hydrocarbons were first used, then phosphates, and recently the carbamates have been used. hidrokarbon Diklorinasi pertama kali digunakan, kemudian fosfat, dan baru-baru ini karbamat telah digunakan. However, insecticides are often too expensive for resource-poor farmers to use. Namun, insektisida sering terlalu mahal bagi petani miskin sumber daya untuk digunakan. Even where farmers can afford insecticides the health hazards may outweigh the economic benefits. Bahkan dimana petani mampu membeli insektisida bahaya kesehatan dapat lebih besar dari manfaat ekonomi. Studies in the Philippines have indicated that when the effect on farmers health and subsequent lost days of work, and the adverse effect on the environment are taken into consideration, the productivity increases obtained from the utilization of insecticides are minimal. Studi di Filipina telah mengindikasikan bahwa ketika efek terhadap kesehatan petani dan kehilangan hari kerja berikutnya, dan dampak buruk pada lingkungan dipertimbangkan, produktivitas meningkat diperoleh dari penggunaan insektisida sangat minim. Due to their cost, toxicity to man and the environment, the secondary pest problems caused such as the resurgence of the brown planthopper (see Figure 9), and because of the development of insecticide resistant populations, the recent trend in rice IPM has been toward the integration of insect resistant varieties with the conservation of natural control agents. Karena biaya mereka, toksisitas terhadap manusia dan lingkungan, masalah hama sekunder disebabkan seperti kebangkitan dari wereng coklat (lihat Gambar 9), dan karena perkembangan populasi insektisida tahan, tren terbaru dalam beras PHT telah menuju integrasi varietas tahan serangga dengan agen kontrol konservasi alam. Although there are cases where the judicious use of selective insecticides in rice is necessary, routine, calendar-based applications in a non-IPM context are no longer recommended. Walaupun ada kasus di mana penggunaan insektisida selektif bijaksana pada padi diperlukan, rutin, aplikasi kalender berbasis dalam konteks non-PHT tidak lagi dianjurkan.
Figure 9. Resurgence of the brown planthopper. Gambar 9. Kebangkitan dari wereng coklat. The "hopper burned" plot in the foreground has been treated with insecticides while the healthy plot behind it has not been treated. The "hopper dibakar" plot di latar depan telah diobati dengan insektisida sedangkan petak yang sehat di balik itu belum diobati.

Biological Control Pengendalian Hayati

The action of indigenous predators, parasitoids and insect pathogens forms the cornerstone for modern IPM programs on rice. Tindakan predator adat, parasitoid dan patogen serangga membentuk landasan bagi program PHT modern pada beras. Although hundreds of insect species feed on rice only 8% are considered as major pests. Meskipun ratusan pakan jenis serangga di beras hanya 8% dianggap sebagai hama utama. This indicates that over the thousands of years of rice cultivation a relatively stable association between rice insects and their natural enemies has evolved. Hal ini menunjukkan bahwa selama ribuan tahun budidaya padi asosiasi yang relatif stabil antara beras dan serangga musuh alami mereka telah berevolusi. When this stability is upset, as is the case in the destruction of predators by insecticides, insect outbreaks occur (see Figure 9). Ketika stabilitas ini marah, seperti halnya dalam pemusnahan predator oleh insektisida, wabah serangga terjadi (lihat Gambar 9).
Classical and inundative biological control approaches tried so far have had little success in rice. Klasik dan inundative pendekatan kontrol biologis mencoba sedikit keberhasilan sejauh ini telah memiliki beras. However, research studies have shown that indigenous natural enemies have a strong impact on rice pest populations and their conservation is an essential part of rice IPM programs. Namun, studi penelitian telah menunjukkan bahwa musuh alami adat memiliki dampak yang kuat pada populasi hama padi dan konservasi mereka adalah bagian penting dari program PHT padi. Many species of predators, parasitoids and pathogens have been shown to attack rice insect pests. Banyak jenis predator, parasitoid dan patogen telah ditunjukkan untuk serangan hama serangga beras. However, only one example of each will be mentioned. Namun, hanya satu contoh dari masing-masing akan disebutkan.

Parasitoids. Parasitoid.

Numerous parasitoids have been reported attacking the eggs, larvae and pupae of the rice leaffolder, Cnaphalocrocis medinalis in Asia. Banyak parasitoid telah dilaporkan menyerang telur, larva dan pupa dari hama putih palsu beras, Cnaphalocrocis medinalis di Asia. Larval parasitism averaged 40% in studies conducted on the IRRI research farm, and in nearby farmers' fields in the Philippines (Figure 10). parasitisme larva rata-rata 40% pada studi yang dilakukan di peternakan penelitian IRRI, dan di bidang petani dekat 'di Filipina (Gambar 10). From 4,904 larvae collected, 15 species of parasitoids, belonging to 9 families, were found. Dari 4.904 larva dikumpulkan, 15 spesies parasitoid, milik 9 keluarga, yang ditemukan.
Figure 10. Seasonal incidence of leaffolder parasitism. Gambar 10. Insiden Musiman parasitisme hama putih palsu.

Predators Predator

Predacious arthropods, including insects and spiders, attack all stages of rice insects. arthropoda ganas, termasuk serangga dan laba-laba, menyerang semua tahapan serangga beras. Spiders are abundant in rice fields throughout the world. Laba-laba yang melimpah di sawah di seluruh dunia. The wolf spider, Lycosa pseudoannulata (Figure 11) is probably the most important predator in rice fields in Asia. Laba-laba serigala, Lycosa pseudoannulata (Gambar 11) mungkin adalah predator yang paling penting di sawah di Asia. The diet of the wolf spider depends on the types of insects that are available but leafhoppers and planthoppers are the major prey. Diet laba-laba serigala tergantung pada jenis serangga yang tersedia tetapi wereng dan wereng adalah mangsa utama. Lycosa feeds on both hopper nymphs and adults and is considered to be a major regulator of brown planthopper populations. Lycosa feed pada kedua nimfa hopper dan orang dewasa dan dianggap sebagai pengatur utama dari populasi wereng coklat. One wolf spider can eat up to 45 hoppers per day. Satu laba-laba serigala bisa makan sampai dengan 45 gerbong per hari.
Figure 11. Spider, Lycosa pseudoannulata . Gambar 11,. Spider Lycosa pseudoannulata.

Pathogens Patogen

Pathogens belonging to the fungi, bacteria and virus groups attack rice insect pests and play an important role in the regulation in rice insect pest populations. Patogen milik jamur, bakteri dan virus kelompok padi serangan hama serangga dan memainkan peran penting dalam regulasi pada padi populasi hama serangga. Among the entomogenous fungi, Metarhizium anisopliae , the "green muscardine fungus", is a common insect pathogen. Metarhizium anisopliae commonly attacks rice planthoppers, leafhoppers and rice black bugs, Scotinophara sp. Di antara jamur patogenik, Metarhizium anisopliae, yang "hijau jamur muscardine", adalah patogen serangga yang umum. Metarhizium anisopliae umumnya serangan wereng padi, wereng dan hitam bug beras, Scotinophara sp. A dead black bug, covered by white mycelia of M. Sebuah bug hitam mati, ditutupi oleh miselia putih M. anisopliae , is shown in Figure 12. anisopliae, ditunjukkan pada Gambar 12.
Figure 12. Black bug, Scotinophara sp. Gambar 12. Bug Hitam, sp Scotinophara. infected with fungus, Metarhizium anisopliae . terinfeksi jamur, Metarhizium anisopliae. (courtesy of BM Shepard). (Courtesy of BM Shepard).

Plant Resistance to Insects Perlawanan terhadap Serangga Tanaman

Resistant cultivars are sought as the major tactic in an integrated approach to rice insect control. kultivar Tahan dicari sebagai taktik utama dalam pendekatan yang terintegrasi untuk mengontrol beras serangga. Incorporation of insect resistance into modern varieties is a major objective of most rice breeding programs in developing countries because: Pendirian resistensi terhadap serangga menjadi varietas modern adalah tujuan utama dari program beras paling berkembang biak di negara berkembang karena:

• income per hectare in rice production is relatively low and pendapatan per hektar dalam produksi padi relatif rendah dan
• money spent for controls, such as insecticides, significantly lowers profits, uang yang dibelanjakan untuk kontrol, seperti insektisida, secara signifikan menurunkan laba,
• resistance in rice cultivars is essentially free to the farmer, perlawanan di kultivar padi pada dasarnya bebas untuk petani,
• insecticides cause accidental poisoning accidents and pollute the environment, insektisida menyebabkan kecelakaan keracunan dan mencemari lingkungan,
• land holdings of most rice farmers are small and thus maintaining kepemilikan lahan petani padi yang paling kecil dan dengan demikian mempertahankan
• insecticide application equipment is not economical, and peralatan aplikasi insektisida tidak ekonomis, dan
• varietal resistance is generally compatible with other control tactics. ketahanan varietas secara umum kompatibel dengan taktik kontrol lainnya.

Because of its unique advantages host plant resistance is sought after as a key tactic in the integrated control of rice insect pests in developing countries. Karena perlawanan tuan rumah keunggulan yang unik tanaman dicari sebagai taktik kunci dalam pengendalian hama terpadu beras di negara-negara berkembang. The identification of insect resistant rice germplasm and its use in the breeding of high yielding varieties with resistance to multiple stresses has been an integral part of the of the success of the "Green Revolution" and has increased the profitability of rice production, minimized safety risks to farmers, and contributed to a more healthful environment. Identifikasi plasma nutfah padi tahan serangga dan penggunaannya dalam pemuliaan varietas unggul dengan resistensi terhadap beberapa stress telah menjadi bagian integral dari keberhasilan dari "Revolusi Hijau" dan telah meningkatkan profitabilitas produksi beras, risiko keselamatan diminimalkan kepada petani, dan memberikan kontribusi pada lingkungan yang lebih sehat.

Evaluation of Rice Germplasm for Insect Resistance. Evaluasi Plasma Nutfah Beras untuk Ketahanan serangga.

It has been estimated that the number of rice cultivars in collection may reach 120,000. Telah diperkirakan bahwa jumlah kultivar padi dalam koleksi mungkin mencapai 120.000. The IRRI International Rice Germplasm Center, established in 1961, has about 80,000 accessions of O. sativa, 2,408 strains of O. glaberrima and 2,214 wild species and species-hybrids. The International Rice IRRI Plasma Nutfah Center, didirikan pada tahun 1961, memiliki sekitar 80.000 aksesi O. sativa, 2408 strain glaberrima O. dan 2.214 spesies-spesies liar dan hibrida. This collection is the world's largest repository for a single crop. Koleksi ini adalah terbesar di dunia repositori untuk tanaman tunggal. To provide extra security for the IRRI collection the institute deposits a duplicate set of seed in the US National Seed Storage Laboratory, Fort Collins, Colorado, USA. Untuk memberikan keamanan ekstra untuk pengumpulan IRRI deposito lembaga duplikat set benih di US National Seed Storage Laboratorium, Fort Collins, Colorado, USA.
Methods to screen the germplasm collection to identify insect resistant cultivars for use as donors in the breeding programs have been developed for more than 30 rice insect species throughout the world. Metode ke layar koleksi plasma nutfah untuk mengidentifikasi kultivar tahan serangga untuk digunakan sebagai donor dalam program penangkaran telah dikembangkan selama lebih dari 30 jenis padi serangga di seluruh dunia. In Asia and South America major emphasis has been on the leafhoppers, planthoppers and stem borers. Di Asia dan Amerika Selatan penekanan besar telah di wereng, wereng dan penggerek batang. In the USA, major emphasis has been on the rice water weevil. Di Amerika Serikat, penekanan utama telah di bonggol air beras.

Breeding Insect Resistant Rice Varieties. Pemuliaan Varietas Padi Tahan Serangga.

Breeding for insect resistance has only been a focus of rice development programs since the early 1960s. Pemuliaan untuk ketahanan serangga hanya menjadi fokus program pembangunan beras sejak awal 1960-an. Although rice breeding programs throughout the world have developed and released commercial varieties with resistance to numerous insect species, emphasis in this section will be primarily on the brown planthopper as a typical example. Meskipun program pemuliaan padi di seluruh dunia telah dikembangkan dan dirilis varietas komersial dengan resistensi terhadap spesies serangga banyak, penekanan pada bagian ini akan terutama pada wereng coklat sebagai contoh yang khas.
All of the major rice producing countries in South and Southeast Asia have breeding programs to control this pest. Semua negara penghasil beras utama di Asia Selatan dan Asia Tenggara memiliki program pemuliaan untuk mengendalikan hama ini. Rice cultivars resistant to the brown planthopper were first identified at IRRI in 1963. Padi kultivar tahan terhadap wereng coklat pertama kali diidentifikasi di IRRI tahun 1963. Since 1963 about 50,000 accessions have been tested and more than 400 resistant accessions have been identified. Sejak 1963 sekitar 50.000 aksesi telah diuji dan lebih dari 400 aksesi tahan telah diidentifikasi.
Seven genes have been identified that impart resistance to the brown planthopper; Bph 1, bph 2, Bph 3, bph 4, bph 5, Bph 6 and bph 7. Tujuh gen telah diidentifikasi bahwa perlawanan memberi ke wereng coklat; bph BPH 1, 2, BPH 3, bph 4, 5 bph, BPH 6 dan 7 bph. IR36, once the most widely grown rice variety in the world has multiple resistance to several diseases and insects, including the brown planthopper, good grain quality, and high yield potential. IR36, setelah yang paling banyak ditanam varietas padi di dunia memiliki ketahanan ganda untuk beberapa penyakit dan serangga, termasuk wereng coklat, kualitas biji baik, dan potensi hasil tinggi.

Insect Resistant Cultivars as a Component in IPM Systems. Serangga Kultivar Tahan sebagai Komponen dalam Sistem PHT.

Insect resistant varieties are being successfully utilized, as a major component in rice IPM. varietas tahan serangga sedang berhasil digunakan, sebagai komponen utama dalam PHT padi. IPM programs utilize biological controls, traditional cultural controls, insecticides and pest resistant varieties to varying degrees. program PHT menggunakan kontrol biologis, kontrol budaya tradisional, insektisida dan varietas tahan hama dengan derajat yang bervariasi. The cornerstone of the Indonesian rice IPM strategy is the use of multiple pest resistant varieties in a mix with natural biological control and other control tactics. Landasan strategi PHT padi Indonesia adalah penggunaan beberapa varietas tahan hama dalam campuran dengan kontrol biologis alami dan taktik pengendalian lainnya. Examples of how insect resistant varieties can be integrated with biological, cultural and chemical control are now presented. Contoh bagaimana varietas tahan serangga dapat diintegrasikan dengan kontrol biologis, budaya dan kimia sekarang disajikan.

Plant Resistance to Insects and Biological Control. Tanaman Resistensi terhadap Serangga dan Kontrol Biologi.

Insect resistant varieties may have an adverse effect on natural enemies by reducing prey density, but they are generally considered to be compatible with biocontrol agents. Serangga varietas tahan mungkin memiliki efek buruk pada musuh alami dengan mengurangi kepadatan mangsa, tetapi mereka umumnya dianggap kompatibel dengan agen biokontrol. The combination of multiple pest resistance and natural biological control, is especially attractive in developing countries in the tropics where extension services are often not able to train farmers in IPM principles and practices. Kombinasi beberapa ketahanan terhadap hama dan kontrol biologis alami, terutama menarik di negara berkembang di daerah tropis dimana penyuluhan sering tidak mampu melatih para petani dalam prinsip-prinsip PHT dan praktek. Pest resistant varieties shift the pest:predator ratio in favor of biological control. Pest varietas tahan menggeser hama: rasio predator mendukung kontrol biologis. In field studies in the Philippines, brown planthopper: spider ratios decreased with an increase in the level of resistance. Dalam studi lapangan di Filipina, wereng coklat: rasio laba-laba menurun dengan peningkatan tingkat resistensi.
Host plant resistance enhances predatory activity in a manner which may be synergistic. ketahanan tanaman Host meningkatkan aktivitas predator dengan cara yang dapat sinergis. Predation rate of the wolf spider increases when the spider preys on brown planthopper adults on resistant cultivars. Tingkat pemangsaan meningkat laba-laba serigala ketika laba-laba dewasa memangsa wereng coklat pada kultivar tahan. The mechanism involved is believed to be the restless nature, and subsequent frequent movement of the brown planthoppers on the resistant variety, which exposes them to a greater degree to detection by the spider. Mekanisme yang terlibat adalah diyakini sifat gelisah, dan gerakan sering berikutnya dari wereng coklat pada varietas tahan, yang membuat mereka ke tingkat yang lebih besar untuk deteksi oleh spider.
Combinations of host plant resistance and predation by the mirid bug, Cyrtorhinus lividipennis have a cumulative effect on the population increase of the green leafhopper, Nephotettix virescens, a vector of the dreaded tungro virus. Kombinasi resistensi tanaman inang dan pemangsaan oleh bug mirid, lividipennis Cyrtorhinus memiliki efek kumulatif terhadap peningkatan populasi wereng hijau, virescens Nephotettix, vektor dari virus tungro ditakuti. In cage studies the number of leafhoppers only reached 6 on leafhopper resistant IR29, with the predator, and 31 without the predator, while there were 91 and 220 leafhoppers respectively on susceptible IR22 (Figure 13). Dalam studi kandang jumlah wereng hanya mencapai 6 pada IR29 yang tahan wereng, dengan pemangsa, dan 31 tanpa predator, sementara ada 91 dan masing-masing 220 wereng pada IR22 peka (Gambar 13).
Figure 13. Population of the green leafhopper as affected by level of varietal resistance. Gambar 13. Penduduk dari wereng hijau yang dipengaruhi oleh tingkat ketahanan varietas.

Plant Resistance to Insects and Cultural Control Tanaman Resistensi terhadap Serangga dan Kontrol Budaya

Most cultural practices are considered to integrate well with other control tactics in IPM systems, and the use of resistant varieties, combined with good cultural management, is considered to be a powerful tool in managing pests. praktek-praktek budaya Sebagian besar dianggap untuk mengintegrasikan dengan baik dengan taktik kontrol lainnya dalam sistem PHT, dan penggunaan varietas tahan, dikombinasikan dengan manajemen budaya yang baik, dianggap menjadi alat yang ampuh dalam mengelola hama. Examples of integration are resistant varieties plus (1) fertilizer management, and/or (2) pest evasion techniques. Contoh integrasi adalah varietas tahan plus (1) manajemen pupuk, dan / atau (2) teknik penghindaran hama.
Increased amounts of nitrogen fertilizer has been one of the major components contributing to the high yields of modern crop cultivars. Peningkatan jumlah pupuk nitrogen telah menjadi salah satu komponen utama yang berkontribusi terhadap imbal hasil tinggi kultivar tanaman modern. However, high plant nitrogen levels, are generally favorable to pest insect populations. Namun, tingkat nitrogen tinggi tanaman, umumnya menguntungkan untuk populasi hama serangga. Results of a study indicated that nitrogen fertilizer favors brown planthopper population growth, regardless of the level of resistance in the host plant, but the population increase is least at the higher levels of resistance, such as on highly resistant IR60. Hasil penelitian menunjukkan bahwa pupuk nitrogen nikmat pertumbuhan populasi wereng coklat, terlepas dari tingkat resistensi pada tanaman inang, namun peningkatan populasi paling tidak di tingkat yang lebih tinggi perlawanan, seperti pada IR60 sangat tahan.
Figure 14. Brown planthopper populations as affected by varietal resistance and N fertilizer rates in a greenhouse study. Gambar 14 wereng. Populasi Brown sebagai dipengaruhi oleh ketahanan varietas dan tingkat pupuk N dalam studi rumah kaca.
Cultural practices employed to evade pest attack include early maturing varieties which are harvested before the pest reaches damaging populations. praktek budaya yang digunakan untuk menghindari serangan hama termasuk genjah varietas yang dipanen sebelum mencapai merusak populasi hama. Brown planthopper: predator ratios on early maturing rice varieties are lower than those on late maturing varieties. wereng Brown: predator rasio pada awal varietas padi jatuh tempo lebih rendah dibandingkan pada varietas jatuh tempo akhir. Incorporation of even moderate levels of brown planthopper resistance into early maturing varieties enhances the level of protection against this pest. Pendirian moderat bahkan tingkat resistensi wereng coklat ke dalam varietas genjah meningkatkan tingkat perlindungan terhadap hama ini.

Plant Resistance to Insects and Chemical Control Tanaman Resistensi terhadap Serangga dan Kontrol Kimia

Because of the weakened physiological condition of insects feeding on resistant varieties control of the surviving insects with insecticides is more effective, when pests are on resistant, than when they are on susceptible, varieties. Karena kondisi fisiologis melemah serangga makan pada pengendalian varietas tahan serangga hidup dengan insektisida lebih efektif, ketika hama berada di tahan, daripada ketika mereka berada di rentan, varietas. Brown planthopper mortality, when reared on either a moderately resistant (ASD7), or a highly resistant (Sinna Sivappu) rice variety, is higher than when feeding on a susceptible (TN1) variety (Figure 15). mortalitas wereng Brown, ketika dipelihara di kedua atau agak tahan (ASD7), yang sangat tahan (Sinna Sivappu) varietas padi, lebih tinggi daripada ketika makan di berbagai (TN1) peka (Gambar 15).
Figure 15. Mortality of brown planthopper as affected by insecticide type and level of varietal resistance (S=susceptible, MR=moderately resistant, and R= resistant). Gambar 15). Kematian wereng coklat yang dipengaruhi oleh jenis insektisida dan tingkat ketahanan varietas (S = rentan, MR = agak tahan, dan R = tahan.
Another interaction of host plant resistance and insecticides is the relationship between level of resistance and insecticide-induced, brown planthopper resurgence. Interaksi lain ketahanan tanaman inang dan insektisida adalah hubungan antara tingkat resistensi dan insektisida-induced, kebangkitan wereng coklat. Brown planthopper populations on a resistant rice variety treated with a resurgence-inducing insecticide only reached 10 insects per plant, whereas the population on a treated susceptible variety was 1,100 per plant. Thus, when insects other than the brown planthopper reach populations above the economic threshold, and require insecticide treatment, the level of brown planthopper resurgence can be reduced, by planting a brown planthopper resistant variety.
Development of "Biotypes" on Insect Resistant Rice Varities. Insect populations have a wide range of genetic variability that maximizes their fitness in the presence of genetic diversity of host plants. The widespread planting of one rice variety (monocrop) that has been commonplace since the "Green Revolution" has significantly decreased the genetic diversity of rice plants. As a result, some rice insect species have overcome the resistance of certain rice varieties. Such apparently new forms of pests have been termed 'biotypes' which refers to a population of insects that is capable of damaging plant varieties that are resistant to other populations of the same species.
Brown planthopper biotypes have been a very severe problem in South and Southeast Asia. IR26 with the Bph 1 gene for resistance was the first brown planthopper resistant variety released by IRRI in 1974. Within the Philippines, brown planthopper outbreaks were observed in IR26 after 2 to 3 years of commercial cultivation (approximately 6 crops) as the result of a selection of a strain that could feed on IR26 (biotype 2). Resistant varieties released subsequently to IR26 have also succumbed to biotype selection within a few years after release as indicated in Figure 16 which shows the reaction of varieties IR32, IR36 and IR38 (with the bph 2 gene for resistance) to brown planthopper biotype 3 in greenhouse feeding tests.
Figure 16. Response (hopperburn) of susceptible rice varieties with no resistance gene (IR 8 to IR24) and varieties with Bph1 (IR 26 to IR 30), bph2 (IR 32 to IR 42), Bph3 (IR 13543) and bph4 (IR 13240) genes for resistance to the brown planthopper in seedbox feeding tests. Varieties with the Bph1, Bph3 and bph4 gene are resistant and those with the bph2 gene are susceptible to biotype 3.
To cope with the brown planthopper biotype problem several gene deployment strategies have been proposed to increase the stability of insect resistant varieties. These strategies are (1) sequential release where a variety with a single major resistance (R) gene replaces a variety with an R gene that has been overcome by the selection for a virulent biotype, (2) gene pyramiding, the incorporation of two or more major R genes into the same variety to provide resistance to two or more biotypes, (3) horizontal resistance, a type of resistance that is expressed equally against all biotypes, (4) gene rotation, a strategy where varieties with different R genes are used in different cropping seasons to minimize selection pressure on given resistance genes, and (5) geographical deployment, the planting of varieties with different R genes in adjacent cropping areas.

Use of Biotechnology

Developing Insect Resistant Rice Varieties. Pengembangan Varietas Padi Tahan Serangga. Recent advances in biotechnology provide the possibility of solving some of the constraints that have limited the practical use of genetic resistance to insects in pest management programs. Biotechnology provides new possibilities of manipulating germplasm.
Wide hybridization. Wide hybridization is a plant breeding tool for the incorporation of alien genetic variation from wild species of Oryza into commercially useful cultivars. Wild rice species are a rich source of R genes for use in breeding programs for insect resistance. The IRRI breeding program has utilized the wild rice species O. brachyantha in the development of crosses with O. sativa in the development of brown planthopper resistance. Some progeny are resistant to all known biotypes of the brown planthopper.
Genetic Transformation. IRRI scientists in cooperation with the Rockefeller Foundation Biotechnology Network are incorporating novel genes for resistance into rice through transformation. Genes, such as the Bt (Bacillus thuringiensis) gene coding for toxic proteins, inhibitors of digestive enzymes such as protease inhibitors, and ribosome inactivating genes are being transferred to rice.

Insect Resistant Cultivars and Control of Non-insect Pests.

There are a myriad of interactions among the various pests (insects, diseases, nematodes, rodents, and weeds) that attack rice plants. The control of a target pest may cause population increases, or decreases, or may not affect another pest.
Weeds and plant diseases may be adversely affected by the planting of insect resistant varieties. Insects that feed on susceptible seedlings and plants, in the vegetative stage, slow rice plant growth and reduce the plant foliage area. This causes the closing of the plant canopy to be delayed and reduces the competition for light and nutrients which in turn allows greater weed growth.
Insect feeding predisposes rice plants to attack of bacterial and fungal pathogens that invade the insect-damaged plant tissue. Some insect species, especially the leaf- and planthoppers, are rice virus vectors. Decrease in the feeding activity on non-preferred rice varieties decreases the incidence of virus infection.

Utilization of Insect Resistant Rice Varieties.

Host plant resistance has served as a key component in IPM programs and in the development of sustainable rice production systems. National rice research programs in many countries have made significant progress in the development and release of pest-resistant varieties. It would be difficult to cover in detail all of these programs so we will limit our discussion to the program at IRRI in the Philippines.
IRRI's rice improvement program has placed major emphasis on developing germplasm with multiple resistance to key diseases and insects. The widespread adoption of such varieties has helped to stabilize rice production in Asia. As Figure 17 indicates, the yield of insect and disease susceptible IR8 fluctuates significantly from year to year depending on disease and insect pressure and shows a gradual, mean decline over 20 years. When new varieties with multiple resistance are introduced there are only minor fluctuations in yield, as these varieties have greater yield stability . An estimate of the contribution of host plant resistance to maintain yield is given in Figure 17. Yields of the original high-yielding varieties such as IR8 would have declined an average of 1.3% per year, or a total of 2 t/ha over a 20-year period without crop improvement to incorporate multiple pest resistance. The sequential release of varieties with diverse genes is necessary to cope with the development of new races and biotypes of diseases and insects respectively.
Figure 17. Yield stability of new pest resistant varieties compared to IR8 in IRRI tests.
Modern varieties have rapidly spread in the major rice growing countries and have had a significant economic and social impact. In the Philippines, 94% of the area is planted to modern varieties, and modern varieties occupy 100% of the rice area in China Japan and the USA. Variety IR36 with multiple resistance to insects and diseases was once grown on about 16 million ha in Asia. The availability of rice varieties with multiple resistance to insects and diseases has stabilized yields, increased farmer income, minimized the need for pesticides and has promoted the adoption of IPM practices.

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Pests and diseases plague rice crops

Farmers get instructions on how to properly mix chemicals that can prevent pests, insects and rice diseases in Hiep Hoa District, Bac Giang Province. Rice diseases are causing widespread damage to rice crops in northern and central provinces. — VNA/VNS Photo Dinh Hue

HA NOI — Pests, insects and rice diseases have caused widespread damage to rice crops in northern and central provinces.

Changeable weather, including a prolonged hot spell, had created favou-rable conditions for pests and insects, reported the Ministry of Agriculture and Rural Development's Plant Protection Department.

Head of the department Nguyen Xuan Hong said that the improper use of pesticide at the beginning of the crop had possibly contributed to the situation.

Natural enemies including snakes and toads had been killed, leading to an ecological imbalance, which provided ideal conditions for the growth in insect numbers, he said.

Over 5,200ha of the rice crop in 19 northern provinces, including Son La, Lao Cai, Dien Bien, Thai Binh and Hai Duong, had suffered from black stunt disease.

Rice leaf folders, which infest rice crops by rolling the leaves around themselves to survive inside, reportedly appeared and damaged nearly 100,000ha of crop in the central coastal provinces of Nghe An, Ha Tinh and Thua Thien-Hue.

Average insect density was about 50-70 insects per square metre but in hardest-hit areas, 700 insects per square metre could be found.

In addition, 60,000ha of the summer-autumn crop had reportedly been hit by various pests.

High risk

Nghe An Agriculture and Rural Development Department's deputy director Nguyen Van Lap said that local farmers faced a high risk of crop loss because of drought and rice diseases.

Rice leaf folders have hit over 41,000ha of rice fields in Nghe An with a density of 150-200 insects per square metre. Black streaked dwarf disease has also spread in 2,300ha over 11 districts.

At least 70ha of paddy rice crop in northern Bac Giang Province's Hiep Hoa District are suffering from an unidentified viral disease that has made the rice leaves turn yellow and then red, leaving the rice paddy withered.

The infected fields were mainly in the communes of Hoa Son, Thai Hoa and Que Son.

The district People's Committee vice chairman Nguyen Van Chinh said that hundreds of hectares of paddy field was vulnerable to catching the disease because of the high speed of contamination.

He said that the locality witnessed the disease in the previous rice crop at the same time last year.

The disease hit 600ha out of 8,000ha rice crop in the district, reducing productivity by between 10-40 per cent.

A local farmer Luong Thi Canh, of Hoa Son Commune, said she saw evidence of the disease some 10 days ago but two or three days later, all of her 0.5-ha – paddy field had turned yellow despite her using pesticide.

She said she was worried about losing her main crop.

Experts from Plant Protection Institute and Ha Noi Agriculture University said their laboratory tests found the disease was caused by a virus.

More exact findings would be released in the next two weeks, said La Van Trong, a Thai on Commune agriculture officer. — VNS