茚虫威在红火蚁工蚁间的横向接触传导效应

[背景]红火蚁是我国重要的外来入侵害虫。利用其相互清洁和交哺行为等社会性昆虫特有的生活习性,使杀虫剂在巢群内传导,可以达到全巢药剂控制的目的。然而,有关茚虫威在红火蚁巢群内的传导效应尚未见有详细报道。[方法]采用供药蚁/受药蚁模型,研究了药剂剂量、供药蚁—受药蚁比例、处理时间对茚虫威在红火蚁工蚁间横向传毒的影响。[结果]剂量越高,受药蚁的死亡率越高,25 ng·头-1处理组受药蚁死亡率为14.1%～70.0%,而50 ng·头-1处理组的受药蚁死亡率最高可达100%;供药蚁—受药蚁比例显著影响茚虫威的传毒,比例为1∶1时,50、100、250、500 ng·头-1处理组受药蚁死亡率可达100%;随着时间延长,受药蚁的死亡率升高,但在12 h后,供药蚁死亡率最高仅为8.0%,表明茚虫威具缓效特性。[结论与意义]本研究明确了在红火蚁工蚁间茚虫威横向传毒的剂量、时间和供药蚁—受药蚁比例的效应,为应用该药剂提供了依据。

Horizontal transfer of indoxacarb among red imported fire ant workers

[ Background] The red imported fire ant, Solenopsis invicta Buren, is an invasive pest of economic importance. Whole nest chemical eradication can be achieved by horizontal transfer of insecticides through contact mediated by the habits of grooming or trophallaxis. The potential of horizontal transfer of the insecticide indoxacarb within fire ant nest is unclear. [ Method] The effects of dose, donor-recipient ratio, and time allocated for horizontal transfer indoxacarb among fire ant workers were studied by using a do- nor-recipient model. [ Result ] Higher doses of indoxacarb resulted in greater recipient mortality. The mortality of the recipients ranged from 14.1 to 70.0% when exposed to 25 ng · worker-1. A dose of 50 ng · worker-1 killed 100% of the recipients. Donor- recipient ratio significantly affected the exchange rate of indoxacarb. With a 1：1 donor-recipient ratio, mortality reached 100%. Re- cipient mortality increased as exposure time increased. The highest 8.0% mortality occurred after exposed 12 h indicating a delayed activity of indoxacarb. [ Conclusion and significance] The effects of dose, time, and donor-recipient ratio on the horizontal transfer of the indoxacarb among the fire ant workers provided a basis for the application of the insecticide.