Effects of the insecticide triazophos on the ultrastructure of the flight muscle of the brown planthopper Nilaparvata lugens Stal (Hemiptera: Delphacidae).

摘要

The brown planthopper (BPH), Nilaparvata lugens (Stal) (Hemiptera: Delphacidae), is a long-distance migratory insect pest in temperate eastern Asia and is a classical resurgent rice pest that is induced by insecticides. Knowledge of the effect of insecticides on the flight capacity of insects is needed to understand their migration, which may help to improve the management of insect pests. Our previous study demonstrated that some insecticides enhance the flight capacity of BPH. However, the effect of insecticides on the flight muscle of BPH is not well understood. Thus, the present study examined the effect of triazophos, a classical insecticide that induces the resurgence of BPH, on the ultrastructure of macropterous females using transmission electron microscopy. The results showed that the diameter of myofibrils one and two days after adult female emergence (DAE) following treatment with 40 ppm triazophos was significantly greater than that of the control, increasing by 31.4 and 21.5%, respectively. In addition, the length of the sarcomeres at two and three DAE was significantly greater than that of the control, increasing by 73.8 and 50.8%, respectively. The percentage of mitochondrial volume in the muscle fibres at one and two DAE was 146.2 and 67.7% greater than that of the control, respectively. These findings show that the mechanisms of triazophos-induced enhancement of the flight capacity of BPH involve changes in the ultrastructure of the flight muscle.