Evaluation on the paddy dwelling chironomids in view of IPM
Grant-in-Aid for General Scientific Research (C)
|Allocation Type||Single-year Grants|
|Research Institution||Yamaguchi University|
YANO Koji Faculty of Agriculture Yamaguchi University, Professor, 農学部, 教授 (90038208)
HAMASAKI Shosaburo Faculty of Agriculture Yamaguchi University, Lecturer, 農学部, 講師 (10035107)
HIRAO Jutaro Faculty of Agriculture Yamaguchi University, Professor, 農学部, 教授 (40218764)
|Project Period (FY)
1990 – 1991
Completed(Fiscal Year 1991)
|Budget Amount *help
¥2,200,000 (Direct Cost : ¥2,200,000)
Fiscal Year 1991 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1990 : ¥1,400,000 (Direct Cost : ¥1,400,000)
|Keywords||Paddy Dwelling Chironomids / Development of Larvae / Drought Resistance of Larvae / Population Density of Larvae and Adults / Density in Paddy Fields / Predaceous Insects / IPM / 成虫の密度 / 水田内の分布|
1) Chironomid species recorded from paddy fields in the world
A total of 158 species belonging to 3 subfamilies and 49 genera of the Chironomidae were recorded from the world paddy fields up to present. The insect group is the most diverse and dominant in the paddy field ecosystem.
2)Development of chironomids
Larval instars, larval development, total effective temperature, developmental period, emergence rhythm of adults, adult longevity, number of ovarian eggs, sex ratio of Tanytarsus oyamai Sasa and Glyptotendipes tokunagai Sasa were studied and the data concerned were obtained.
3)Population density in paddy fields
Adult chironomid populations occurring in paddy fields were estimated by systematic samplings using emergence traps. It was estimated as 4.14 million in a paddy (691 m^2) during 3 months. It was about 6, 000/m^2. Larval density in the same paddy was estimated as 4.13 million during 65 days, and it seemed to be under estimated judging from the sampling method and other reasons.
4)Drought resistance of larvae
Drought resistance of the last instar larvae of Glyptotendipes tokunagai was tested by rearings under different water content of media. Drying media allowed the larvae alive for 30 - 50 days until the water content decreased to 30%.
5)Predeaceous insects of chironomid larvae
A total of 16 species belonging to Odonata (6 species), Hemiptera-Heteroptera (4 species) and Coleoptera (6 species) were observed as aquatic predatory species of chironomid larvae.
Thirteen species among them were reared to find their feeding habit especially the number of chironomid larvae eaten for food.
Research Output (19results)