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Improvement of Rice Insect Pests Control Measures in Taiwan
No full text台灣水稻害蟲重要者只有10 餘種，其中關鍵害蟲隨耕作制度的演變而屢有更迭；為防治關鍵害蟲之危害，防治策略隨害蟲種類之演變，防治技術之研發與社會之需求而變動“在1950 年以前，對主要害蟲之防治以耕作防治、生物防治及以植物或非有機物質防治，效果有限。1950 年後有機合成殺蟲劑引入本省對各種害蟲均以撒佈廣效而持久性殺蟲劑防治為主；過度使用農藥常導致飛蝨及葉蟬類之猖獗發生。1970 年代中期後防治策略因病害蟲發生預測制度之建立，而逐漸演變為於適當時期使用短效性殺蟲劑防治。1980 年代中期後由於害蟲之經濟為害基準及防治適期之釐定，抗蟲品種之推廣，以及短效性及選擇性殺蟲劑之問世，而逐漸以害蟲綜合防治方法防治水稻害蟲。在1990 年代，因社會變遷，稻農年齡老化，兼業農民日眾，且政府為加入貿易總協，水稻栽培除機械插秧外，並獎勵直播、再生栽培或休耕，害蟲發生種類及其發生高峰期均明顯變動，文中對機插栽培稻之管理缺失以及直播稻、再生稻之蟲害管理策略和今後待加強之研究項目均有簡要之描述。
About 140 species of rice insect pests had ever been recorded in Taiwan, but less than 10 species were economic importance. The key pest species of rice were variable following the change of cultural practices. As the result, the measures used for controlling the insect pests were also revised according to the change of key pest species, and also available techniques and social requirement. Before the years of 1950, the important insect pests on rice were yellow rice borer (Scirpophaga incertulas), rice hispa (Diclahispa similis), rice leafbeetle (Oulema oryzae), black rice bug (Scotinophara lurida) and white back planthoppers ( Sogatella fucifera), which were controlled mostly depending on cultural practices, physical methods, natural enemies and natural subtances, but their effectiveness were limited. After organic synthetic insecticides were introduced gradually into Taiwan since 1950, the insect pests was controlled merely depending on the wide- spectrum and long-residual insecticides, which induced consequentially the outbreak of plant-and leafhoppers. Such phenomenon was continuosly to around 1970 after a short-term forecasting system was established that made possible for timing control of insect pests with short-residual insecticides. There- aftr, due to the economic threshold of major insect pests had been developed to set a reliable timing for insecticide application, resistance to key pest rice varieties had been developed and released to farmers, and the insecticide of selective or more safety to natural enemies had been introduced ¡¥ tested and recommended to be used in the years of 1980,all of these components made the feasibility of control insect pests approaching to integrated measures. Recently, in order to meet the requirement of social changes, such as increase of old-aged and part-time farmers, and decline of the cost of rice production for facing the challenges of enterring into WTO, rice culture,beside transplanting with transplanter, direct seeding and ratoon rice have also been encouraged by the government. Such changes have induced the change of pest status in many aspects. Some problem of present control measures in transplanting rice, the measures for control of the insect pests on direct seeding rice and ratoon rice are also described briefly at present paper
Impact of Global Climate Change on Crop Insect Pests in Relation to Pest Control Strategies in Taiwan
No full text影響害蟲族群與為害之環境因子可分為非生物因子與生物因子兩大項，兩者問之相互作用相當複雜，其中任何一因素的改變將可直接或間接地影響到一種害蟲在區域間的族群密度。全球氣候變遷導致地球表面溫暖化可直接影響害蟲之分佈、存活與族群之成長速率，同樣亦可導致作物之發育及其耕種及管理制度之演變，而影響害蟲族群之發生豐度及其為害。在全球氣候變遷下，可使台灣氣候型態更接近熱帶地區，害蟲及其天敵種類之歧異度將更形增加。冬季增加溫度減少降雨量將更有利於害蟲之越冬，增加冬作及春作害蟲之族群密度及為害損失；夏季溫度及降雨量之增高則更不利於害蟲之繁殖，可抑制其為害。由於害蟲之發生豐度受寄主作物之品種、栽培制度及管理方式等之演變影響至大，該等演變導致蟲害之損失，可能較全球氣候變遷之直接影響為大。一般而言，溫度增加，將可增加昆蟲種類的歧異度及發生世代的重疊，較難使用藥劑適時防治，宜發展以增加害蟲環境阻力，如栽植抗蟲品種、增強田間管理，生物與物理防治等非農藥防治方法為主體之綜合管理策略，抑制害蟲族群於經濟危害基準之下，則藥劑使用頻度將可大幅減少，使作物環境更有利於自然潛在天敵族群的增長而發揮其抑制各種害蟲功效。此一防蟲策略將可有效地因應地球表面暖化及社會之需求。
Insect populations are affected by abiotic and biotic environment factors. Global warming will affect the insect distribution, composition of insect foana and the rate of insect population development directly. While the insect population abundance and its damage will be depended on the changes of cultivation and management patterns of crops responding to the weather conditions and social needs. Global climate changes may convert weather in Taiwan from subtropic into tropic conditions, thus providing more favorable situation for the multiplication of arthropods, and increasing species diversity and complexity in the ecosystem. If the weather condition is going to change as predicted, a warmer and drier winter may make conditions more favorable for insects to cause more severe damage in winter and spring crop, while higher temperature and rainfall in summer will hamper the population development of insect pests. However, the total losses of crop caused by insect pests due to the changes of climate directly may be not so much as compared to those due to the changes of varieties, cultural system and management of crops. Management of insect pests in the situation of diverse species and overlapping generations by using biotic measures, such as host plant resistance, biological and cultural measures are more reliable than by insecticidal applications. When successful control of the key pests is achieved through the use of control tactics other than insecticides, opportunity for the control of various potential insect pests by natural enemies will be increased. This control strategy is not only applicable for meeting the situations of global climate changes but also suitable for social demands in Taiwan
Florida red Scale, Chrysomphaius ficus Ashmead
No full textThe infestation of Florida red scale on Citrus is just next to the black Parlatoria in Taiwan. The population is usually decreased during. rainy season from June to September. It infests leaves, twigs and fruits. The severe infested leaves usually fall .down and the twigs die. Resin soda wash could not control this species even though it has been extensively used for control unamored scales and mealybugs until the latest ten years ago. Fortunately 1.3% summer oil emulsive alone or 1 % summer oil emulsive in combination with 0.05 % malathion and 0.05 % dimethoate alone were recommended for control it and Aphytis chryso mphali (Mercet) usually restranis a certain number of individuals
Preliminary observations on the susceptibility of rice varieties to Paddy Borer (Tryporyza incertulas Walker)
No full text1．供試30個水稻品種，枯心率均在30%以上，受害都屬嚴重；白穗率以矮腳種最低4.69%，列為較優抗螟品種；烏占，員粒兩品種均在10%以下，列為中等抗螟品種；其他各品種均列為易受螟害品種。較優抗螟品種與易受螟害品種間之白穗率相差7倍。
2．易受螟害品種的莖內所生存之螟蟲數目較較優抗螟品種莖內者為高，平均最高與最低相差17倍左右。
3．印度型水稻品種之枯心率（34.93%～60%）較日本型品種者（33.11%～56.88%）略高；但白穗率則日本型品種的C15.73%～30.48%）反顯著的較印度型品種者（4.69%～29.46%）為高。
各品種之分蘗期與孕穗期對三化螟蟲為害的感受程度不一致。
4．螟蛾產卵量與各品種之分蘗株數（r=+0.451)，株高(r=＋0.353),劍葉長(r=+408)均具顯著的相關，與劍葉寬相關不明顯，葉面具長毛之品種平均產卵率較光滑品種者為高，達28.78%。
5．水稻在分蘗期受三化螟為害，其被害率與各品種之分蘗株數(r＝-0.55)，具極顯著的相關，與劍葉寬、劍葉長則相關不明顯，葉片具長毛之品種，受害似較不嚴重。
6．水稱早期受螟害區，其晚期平均每叢穗數除CP321×H012及sigadis兩品種，較早期受保護區減少外，其他各品種均普遍增加，增加範圍達0.76%～112.56%，其產量惜受鳥害甚重無法比較計算，在本省栽培制度及螟蟲發生情形下，早期受螟蟲為害是否影響晚期之產量，有待進一步之試驗觀察。
A total of 30 rice varieties were chcsen for test under field condition to determine the variation of susceptibility to Paddy Borers. The test was divided into two parts. Each variety was transplanted in blocks of 1.Oxl.4 meters, in seven rows and four lines, 20 and 25 centimeters apart repectively, and with three replications. Thirty days after transplanting, all of the test varieties in one part of each replication were artificially infested by implanting 4 egg masses on the leaves for the test of maximum tillering stage, while at 70 days it was done on the other part for the late-booting stage test. Observations were made at 60 days after transplanting for dead hearts and at 10 days before harvest for white heads. The surviving larvae whithin a cuim were also counted in each block. Results are shown in Table 1.
The Percentages of dead hearts at maximum tillering stage varied from 33.1 to 60, while infested tiller from 51.01 to 82.92, and white heads at the test of heading stage ranged from 4.69 to 30.48, infested tiller from 10.00 to 48.46. Infestations on the different varieties varied significantly in all measurements but dead heart; the susceptible varieties had about 7 and 8 times more white heads and the number of living larvae per hill than the resistant varieties.
Japonica-type varieties were somewhat less susceptible to Paddy Borers at the early stages of growth than Indica-types, but the formation of white heads, Japonica become even more susceptible than Indica varieties. The results were similar to those obtained by the International Rice Research Institute, (I. R. R. I.) 1963-64.
At the maximum tillering stage, it was found that correlated coefficients recorded between the number of egg masses laid and the height of plant, length of leaves, and the number of tiller were +0.353, +0.408, and +0.451, respectively, but, no significant correlation was found between width of leaves and the number of egg masses. The 1eaf surface in varieties with comparatively long and close hairs appeared to have more oviposition than those with short or sparse hairs. Among the test varieties, the Indica-type varieties generally had more tiller, higher cuim, and hairy leaf surface, and hence, more eggs masses were laid.
Paddy Borers infested at the maximum tillering stage, the average number of tillers per hill in a variety was negatively correlated with the percentage of infested tillers (r= -0.554), but the correlation was not significant at the heading stage.
Height of plant, width and length of leaves showed no relation to borer infested tiller at early growing stage and the heading stage in those test varieties
NEW BIOTYPES OF THE BROWN PLANTHOPPER AND INTERACTION BETWEEN BIOTYPES AND RESISTANCE IN RICE
No full text在室內連續應用抗蟲水稻品種Mudgo（抗褐飛蝨遺傳行為受一對顯性因子所控制），H 105， IR9-60及Samba（三品種抗蟲行為均受一對隱性因子所支配）等分別飼餐自然棲羣褐飛蝨，經20世代陸比較各蟲羣成蟲壽命、緊殖後裔蟲數、生存率，以及偏好性與為害等結果，頭示各蟲重分別能完全適應於用於連檢飼養該蟲羣之水稻品種而形成三種不同的生物小種。生物小種間並無明頭之形態上差異，但劉抗褐飛蝨遺傳質不同水稻的反應卻有極明顯的差異。應用上述三種主物小種間對不同抗蟲遺傳質水稻品種為害反應的差異，本試驗己將以往選出之抗蟲品種的抗蟲遺傳類型加以鑑定，並縫現有水稻Mathumanikan及DF1等兩品種對上述三種生物小種兼具抵抗佳，其抗蟲遺傳因子與以往發現者可能具有明顯的差別。
Three biotypes of the brown planthopper have been developed, by feeding caged insects successively on rice having different genes for resistance. The biotypes have been designated Biotype I, Biotype II, and Biotype III. Although biotype II was generally smaller than the others, no distinct differences in morphological characters among biotypes were observed. However the differences in plant-wilting capabilities were obvious. The individuals of Biotype 1, the dominant biotype in the natural population, are capable of wilting rice with the T (N) 1-type resistance (susceptible to all biotypes). Biotype III individuals can wilt rice with T (N) 1-type resistance and H 105 type resistance (resistance control by single recessive gene, which are, resistant to biotype I, moderatelysusceptible to biotype II, and susceptible to biotype III) but can not wilt the rice with Mudgo type resistance (resistance control by single dominant gene, which are resistant to biotype I and biotype III, but susceptible to biotype III). Brown planthoppers of biotype II are capable of wilting rice with T (N) 1-type and Mudgo-type resistance, and also can severely infest rice with H 105-type resistance. With the differences in the reactions of biotypes on rice varieties having different genes for resistance, the resistant genes of varieties Screened previously for resistant to biotype I have been indentified, and the varieties mathumanikan and DF1 are recorded resistant to all mentioned biotypes
(15(3):32-47)ECOLOGY AND CONTROL OF TWO-SPOTTED SPIDER MITE (Tetranychus urticae (KOCH)) ON BANANA
No full text1. 蕉葉二點紅蜘蛛（Tetranychus urticae（Koch）），為本省旱作及特作之重要害蟲，其寄主據調查有69種，較重要者有大豆、花生、甘藷、棉花、番茄、木瓜、蓖麻等。全省各地均有分佈。
2. 受害嚴重之蕉葉，葉背呈誘色，蕉葉萎黃，影響蕉葉壽命及蕉株發育至鉅。
3. 室內飼養，年生24代。完成一個生活圈，須經卵期、幼蟲期、第一若蟲期、第二若蟲期及成蟲等五個發育階段。在蛻變成第一若蟲、第二若蟲期及成蟲之前，須經過一段靜止期（Chrysalis）以準備脫皮。此靜止期為1-2天。各蟲期發育所須日數，受溫度之影響很大。據飼養結果，卵期2-4.86-10天，幼蟲期1-2.68-11天，第一若蟲期1-2.38-8天，第二若蟲期1-2.43-7天。完成一代須時雌蟲6-12.35-23天；雄蟲6-11.94-24天。成蟲壽命3-29.26-55天，產卵前期1-2.13-3天，產卵日期0-26.83-53天，每天產卵數0-1.91-11粒，一生產卵數0-59.17-127粒。
4. 二點紅黑蜘蛛之田間棲羣密度以5-6，9-10，12-3月較高，棲羣消長受天敵、溫度、雨量之影響甚大，溫度高時以蕉株中部葉片之棲羣密度為最高，溫度低時則以下部葉片為高。
5. 所調查之54個香蕉品種中，沖繩芭蕉，味宗蕉，基隆北蕉及Amban等四品種未見受害。同一蕉園中以1公尺以下之幼蕉受害最重，1-2公尺者次之，2公尺以上者受害最輕。
6. 蔽風及與甘藷、花生、大豆等間作，或管理較佳，發育良好之蕉園其蟲口密度較高，受害較重；平地栽培及山地栽培蕉園，在二點紅蜘蛛之發生情形並無多大差異。
7. 二點紅蜘蛛之天敵，據調查有（l）小黑瓢蟲（Stethorus spp.）兩種至三種；（2）小黑隱翅蟲（Oligota sp.）；（3）草蜻蛉（Chrysopa sp.）；（4）六點薊馬（Scolothrip sexmaculatus Perg）；（5）蠳蠅幼蟲（Arthrocnodax occidentalis）；（6）盲椿象一種；（7）Anystis sp.；（8）Typhlodromus spp.（9）寄生菌（Entomophagus sp.）等。
8. 殺埤劑以18.5%Kelthane W.P.，7.05% 48.5% Trithion E.C.，0.05%及50% Trif-enson W.P.，0.05%之防治效果最優。15% BS2525 E.C.，0.05%及20% Tedion W.P.，0.05%之效果較劣。
Two-spotted spider mite (Tetranychus urticae (Koch)) has been estimated an important pest infesting the up-land and fruit crops in rescent years. It was found to be distributed throughout the whole island and infested nearly 70 species of plants. When banana plant was injured, the leaves rusted and wilted and retarded the plant growth at last.
According to the laboratory rearing, this mite took 24 generation from Jan. 17 1965 to Jan 15 1966 at the temperature and relative humidity ranged 13.8-29.7 °C and 58-96.42%, respectively. The oviposited period of females were average 26.83 days ranging from 0 to 53 days. The average eggs laid by each female was 50.17, ranging from 0 to 127. Eggs generally hatched from 2 to 10 days after deposited, the average was 4.86 days. The stages of larvae, protonymph ane deutonymph lasted an average 2.86, 2.39, 2.43 days, respectively, In female, it required an average of 12.35 days to develope into an adult from egg, ranging from 6 to 23 days, while in male, the average days were 11.94, ranging from 6 to 24 days. The duration of each stage and a generation varies with different temperatures.
One larval and two nymphal stages followed by a resting stage were observed in both sexes of this mite. Some of the male matured into adults without the deutonymph stage. Mating process usually accomplished immediately after the last molt of the female. Egg from unfertillized mother gave rise to male offspring only. while those from fertilized mother showed a preponderance of female offspring.
Fleict observations indicated that this mite built up more dense and large colonies in banana plantations where plants were well manage. sheltered from wind, or interplanted with peanut, soybean and sweetpotato. Another observation showed that there were no difference in mite population whether plants were cultured in the up-land or low plough-land areas.
Among the 54 banana varieties, Lung-pia and Kiliang showed more infested by the mite than the others. The mite did not cause any injury to Ching-sheng, Wei-chung and Keelung-pei varieties. However, younger banana plants, below 1 m. in heigh generally are morh heavily attacked, while the older plants of 1 to 2 or beyone 2 m. in height seemed lesser. In the other hand, leaves of the upperpart usually were less infested by mite than the midpart or low-part.
A periodical observation biweekly from Feb. 1965 to March 1966 showed that two-spotted spider mite tended to be higher population during May to June, Sept. to Oct. and Dec. to March. Temperature, rainfall and natural enemies seemed to be the major factors influencing the seasonal fluctuation of mite population. Although the mites are fecundity in the warm late-spring, summer and fall and develop a large number within a short period, but the activities of natural enemies and high moisture could immediately check the increasing of mite population.
Several natural enemies of this mite were observed in Chiayi areas. They are Stethorus spp. (Coccinellidae, Coleop.), Oligota spp. (Staphylinidae, Coleop.), Chrysopa sp. (Chrysopidae, Necurop.), Scolothrips sexmacultatus (Thripidae, Thysanop.), Arthrocodax ociedeniulis (Cecidomyiidae, Dip) Anystis sp. (Anystidae, Acarina), Thyphodromun spp. (Phytoseiidae, Acarina) and one species of Mriridae (Hemip.). Among those, Stethoru.s spp. seemed to be the most active and most effective predator.
Chemical control indicated that a spray of Keithane w. p., Trifenson w. p. or Trithion e. c. at concentration of 0.05%, gave the best control of this mite, while BS2525, Chlorobenzilate, Tedion and CPCBS at same contentration gave only fair control. The plots treated with Tedion or Chlorobenzilate seemed less influence on the population of natural enemies- Stethorus spp. and polyphagus mites. No phytotoucities were obreved in this test
(34(3):299-314)褐飛蝨生物小種與抗蟲稻種之相互作用
No full textBehaviors of four biotypes of the brown planthopper on rice varieties with different resistance genes were investigated. Results showed that the behavioral and physiological responses of a biotype to rice varieties having the same resistance gene on which the biotype was developed, in general, resemble the response to susceptible varieties. The biotypes developed from the varieties with a stronger antibiotic factor to the insect showed more virulent to different varieties than those from a weaker one. Histological studies of the feeding sites in the tissues of resistant varieties revealed that no mechanical barrier to the insect’s feeding involved. However, any biotype put on unsuitable host plants showed restless and changed their feeding sites frequently, and fed less from resistant varieties.
Genetic studies on the ability of biotypes to survive on resistant varieties showed that the virulence of biotype was controlled by polygenes, and dominance effects were the most important factor in determining the inability of biotype to survive on resistant varieties. A simulated study indicated that rotation and mixed planting of plants with different resistance genes will be effective in lowing the rate of development of virulent biotypes.
褐飛蝨為本省水稻重要害蟲，栽植抗蟲品種為一經濟而有效抑制本害蟲的方法。然而當一種抗蟲品種被連續大面積地栽培，可能引起有害生物小種之產生，而危害抗蟲品種。本研究在觀察於室內培育而成之褐飛蝨的四種生物小種在含有不同抗蟲遺傳因子稻種上的行為反應，遺傳以及尋求可能抑制生物小種演化之有效途徑。結果顯示，由一種抗蟲品種汰選而得之生物小種在與該抗蟲品種含有相同抗蟲遺傳因子之所有品種上的行為或生理反應，如同其存活於感蟲品種。由含有抗生性較強之抗蟲品種所汰選而得之生物小種，其危害性亦較由抗生性較弱者汰選所得之生物小種為強。切片檢查各生物小種在各抗蟲品種之取食部位，顯示各種水稻並無明顯的機械障礙可阻止各生物小種由維管束取食。然而若將各生物小種強迫於其不適當的稻種上取食，則顯不安並經常更換取食部位，且減少其取食量，進而影響其存活與繁殖。
探討有害生物小種可存活於抗蟲品種的遺傳行為，顯示係受數量因子所支配，顯性因子效應為控制生物小種不能在抗蟲品種存活之主要因素。本研究亦證明使用輪植或混植含有不同抗蟲因子之稻種可有效地減緩有害生物小種之演化
Citius Red Mite, Panoychus citri McGregor
No full textCitrus red mite Panonychus citri Mcgregor is the most severe pest of citrus in Taiwan recently. Specific charcteristics, life history and habits were briefly described. Six spotted yellow mite Eotetranychus sexmaculatus (Riley) was also given but it does not so harm to citrus at present.
Before introducing malathion and controlling citrus insects with local man-ufactured resin soda wash, lime sulfur, and summer oil, the citrus red mite was not a problem. According to this preliminary test, 9 kinds of organoph-osphorous insecticides it showed that 0.05% of malathion, parathion, sumi-thion were not effective, however, 0.05% ethion, trithion, and pestan were very effective, they could suppress the mite population at unnoticeable level.
Acaricides 0.02% and 0.04% of tedion wp the most effective but the killing action was so slow and could be noticed 3 weeks after application, 0.037% kelthane, 0.05% morocide and 0.1% eradex were the quick action and noticed enough 1 week after qpplication as did as ethion, trithion and pestan but the low concentrations were not effective
綠介殼蟲
No full textSince green scale was introduced to Taiwan it has done considerable damage to coffee, Citrus, Gardenia, etc. It not only weakens the hosts but also induces sooty mould owing to its secretion of honeydew, It also interrupts the photosynthesis of infested plants as well as attracts ants to refuce the parasitic wasp population of both green scale and other citrus insects.
綠介殼蟲Coccus viridis (Green)為外來害蟲之一，現已分布全島，主害柑橘，尤以未結果之幼樹受害最重。本廬之特徵與同屬其他為害柑橘之三種介殼蟲之區別，有作扼要說明。
本種一年發生4～5代，完成一代，夏天需50～70天，冬天需80～100天。產卵前期20～46天，產卵期10～28天，每隻雌蟲產卵量約100拉。雄蟲猶未發現
(54(1):1-14)Evaluation on the Nursery Box Insecticidal Treatment for Control of Early-season Insect Pests of Rice and Its Effect on Predatory Natural Enemies
No full text本試驗選擇0.3%芬普尼 (fipronil) 粒劑120 g/box、3%加保扶 (carbofuran) 粒劑50 g/box 及2%益達胺 (imidacloprid) 粒劑50 g/box 等三種藥劑，以育苗箱藥劑處理方式處理，評估其對害蟲族群之抑制效果，以及其對捕食性天敵的影響。結果顯示益達胺及芬普尼對二化螟蟲為害及飛蝨類族群之抑制效果甚佳，益達胺對葉蟬抑制效果尤為明顯；而芬普尼對瘤野螟之防治效果較佳，其藥效約可維持40-50 天左右；加保扶育苗箱處理對上述害蟲僅具短暫效果，防治效率亦顯較上述兩種藥劑為差。比較育苗箱藥劑處理與藥劑撒佈處理對害蟲防治之效果，顯示以育苗箱藥劑處理之防治效果較為經濟、有效。三種藥劑及處理方式對捕食性天敵之影響均不明顯。本試驗結果，育苗箱藥劑處理僅具防治水稻生育早期害蟲之效果，對於水稻抽穗後之害蟲，應於水稻孕穗中、後期留意其發生狀況，需要時應加施用一次藥劑，以預防害蟲的可能危害。The experiment was conducted to evaluate the efficiency of insecticides such as fipronil, imidacloprid and carbofuran used in nursery-box treatment on control of early season insect pests of rice in paddy field as well as their adverse effect on predatory natural enemies. The experiment conducted from 2002 to 2003 showed that 2% imidacloprid G. at rate of 50g/box was effective for control of rice planthoppers and rice stem borer for about 17 and 9 weeks in the first and second cropping season, while the treatment was poor for control of rice leaffolder. On the other hand, 0.3% fipronil G. at rate of 120 g/box was effective for control of rice planthopper, rice leaffolder and stem borer for 17 weeks in the first cropping season and 7 to 9 weeks in the second cropping season, but it was poor for controlling rice leafhoppers. 3% carbofuran G. at rate of 50 g/box lasted about 10 and 4 to 5 weeks for controlling the rice plant- leafhoppers, stem borer and rice leaffolder in the first and second cropping season, respectively. The efficiency of fipronil G. and carbofuran G. used in nursery box treatment lasted longer efficiency for control of rice insect pests then that of conventional application. Based on the appearing period and the population density of predatory natural enemies in the treated plots, it shows that the tested chemicals used in nursery box treatment did not have distinctly adverse effect to the predatory natural enemies. From present study, it is clear that the nursery box insecticidal treatment was not only effective for control of early-season insect pests but also could lower the pests to infest the crop in the mid- and late stage when a proper insecticide is used. However, it also shows that the nursery box insecticidal treatment alone is not adequate to protect the crop through a cropping season with especially in the second cropping season. One more applications from mid- to late booting stage of rice have to consider when it is needed
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