Cabrera Ana R, Shirk Paul D, Teal Peter E A
University of Florida, Entomology and Nematology Department, Gainesville, Florida, United States of America.
USDA-ARS Center for Medical, Agricultural and Veterinary Entomology, Gainesville, Florida, United States of America.
PLoS One. 2017 Apr 27;12(4):e0176097. doi: 10.1371/journal.pone.0176097. eCollection 2017.
A novel feeding protocol for delivery of bio-active agents to Varroa mites was developed by providing mites with honey bee larva hemolymph supplemented with cultured insect cells and selected materials delivered on a fibrous cotton substrate. Mites were starved, fed on treated hemolymph to deliver selected agents and then returned to bee larvae. Transcript levels of two reference genes, actin and glyceraldehyde 3-phosphate dehydrogenase (GAPDH), as well as for nine selected genes involved in reproductive processes showed that the starvation and feeding protocol periods did not pose a high level of stress to the mites as transcript levels remained comparable between phoretic mites and those completing the protocol. The feeding protocol was used to deliver molecules such as hormone analogs or plasmids. Mites fed with Tebufenozide, an ecdysone analog, had higher transcript levels of shade than untreated or solvent treated mites. In order to extend this feeding protocol, cultured insect cells were incorporated to a final ratio of 1 part cells and 2 parts hemolymph. Although supplementation with Bombyx mori Bm5 cells increased the amount of hemolymph consumed per mite, there was a significant decrease in the percentage of mites that fed and survived. On the other hand, Drosophila melanogaster S2 cells reduced significantly the percentage of mites that fed and survived as well as the amount of hemolymph consumed. The feeding protocol provides a dynamic platform with which to challenge the Varroa mite to establish efficacy of control agents for this devastating honey bee pest.
通过为螨提供补充了培养昆虫细胞和选定材料的蜜蜂幼虫血淋巴，并将其置于纤维棉基质上，开发了一种向瓦螨递送生物活性剂的新型喂食方案。使螨饥饿，用经处理的血淋巴喂食以递送选定的药剂，然后将其放回蜜蜂幼虫。两个参考基因肌动蛋白和甘油醛-3-磷酸脱氢酶（GAPDH）以及九个参与生殖过程的选定基因的转录水平表明，饥饿和喂食方案阶段并未对螨造成高水平的应激，因为在携带螨和完成该方案的螨之间转录水平保持相当。该喂食方案用于递送诸如激素类似物或质粒等分子。用蜕皮激素类似物虫酰肼喂食的螨，其shade转录水平高于未处理或溶剂处理的螨。为了扩展该喂食方案，将培养的昆虫细胞以1份细胞和2份血淋巴的最终比例加入。尽管添加家蚕Bm5细胞增加了每只螨消耗的血淋巴量，但取食并存活的螨的百分比显著下降。另一方面，果蝇S2细胞显著降低了取食并存活的螨的百分比以及消耗的血淋巴量。该喂食方案提供了一个动态平台，用以挑战瓦螨，以确定针对这种毁灭性蜜蜂害虫的防治药剂的功效。
