State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China.
Fujian Province Key Laboratory of Insect Ecology, Department of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China.
Pest Manag Sci. 2017 Jul;73(7):1494-1502. doi: 10.1002/ps.4485. Epub 2017 Jan 6.
The red palm weevil (RPW), Rhynchophorus ferrugineus, is an invasive wood-boring insect that damages palms and sugarcane. Bacillus thuringiensis (Bt) is an entomopathogenic bacterium which has been modified into various strains and widely used in pest management. The aim of this study was to evaluate the susceptibility of RPW to the HA strain of Bt.
Five concentrations of Bt bioassays were used on RPW eggs, second instars and fourth instars. Average egg hatching rates exceeded 85% using Bt suspensions or distilled water. Hatch times were extended significantly using higher Bt concentrations. For second instar larvae, the LC was 4.92 × 10 CFU mL 15 d after feeding; the LT values decreased with each higher concentration. The corrected mortality of second instars increased significantly with increased concentrations after 15 d, ranging from 16.97% to 94.32%. Significant differences occurred in the boring activity of fourth instars when dipped in Bt suspensions or crawling on treated sugarcane. Bacterial infection in dead larvae was confirmed using molecular techniques.
Our results indicated that Bt can be used in RPW control as a potential biological control agent and can effectively reduce palm trees damage. © 2016 Society of Chemical Industry.
红棕象甲（RPW），锈色棕榈象，是一种入侵性的蛀木昆虫，会损害棕榈树和甘蔗。苏云金芽孢杆菌（Bt）是一种昆虫病原细菌，已经被改造成各种菌株，并广泛应用于害虫管理。本研究的目的是评估 RPW 对 Bt 的 HA 菌株的敏感性。
使用 5 种不同浓度的 Bt 生物测定法对 RPW 的卵、二龄幼虫和四龄幼虫进行了测试。使用 Bt 悬浮液或蒸馏水时，平均孵化率超过 85%。使用更高浓度的 Bt 时，孵化时间显著延长。对于二龄幼虫，LC 为 4.92×10 CFU mL ，在喂食后 15 天；LT 值随着浓度的升高而降低。二龄幼虫的校正死亡率在 15 天后随着浓度的增加而显著增加，范围为 16.97%至 94.32%。浸泡在 Bt 悬浮液中的四龄幼虫的蛀蚀活性或在处理过的甘蔗上爬行时，会产生显著差异。使用分子技术确认了死亡幼虫中的细菌感染。
我们的结果表明，Bt 可作为一种潜在的生物防治剂用于 RPW 控制，可以有效减少对棕榈树的损害。© 2016 化学工业协会。
