Zaritsky A, Khawaled K, Barak Z, Chipman D M, Rabi T
Acta Microbiol Pol. 1986;35(3-4):207-14.
Bacillus thuringiensis var. israelensis (B.t.i.) is a promising, safe toxic agent for control of mosquitoes, but the rapid disappearance of its toxicity makes its use in practice economically unattractive. The lack of evidence for B.t.i. multiplication in water also makes the natural ecology of B.t.i. puzzling. The observation that mosquito larvae readily cannibalize carcasses of B.t.i.-killed larvae, and that the carcasses become toxic to scavenging larvae provides a possible solution to this puzzle. Several experimental techniques have been developed to study these phenomena (e.g., quantitative determination of spore numbers despite aggregation, protocols for following toxicity development, etc.). Results suggest a cycle involving larval poisoning and death due to delta-endotoxin of ca. 1,000 spores, germination, vegetative growth and sporulation (with toxin production) of B.t.i. after multiplication to several million in the carcass. Implications of these results for the ecology of B.t.i., and for practical applications in mosquito control, are discussed.
以色列亚种苏云金芽孢杆菌（B.t.i.）是一种很有前景的、用于控制蚊子的安全毒性制剂，但它的毒性迅速消失使其在实际应用中缺乏经济吸引力。缺乏关于B.t.i.在水中繁殖的证据也使得B.t.i.的自然生态令人费解。观察发现，蚊子幼虫很容易同类相食被B.t.i.杀死的幼虫尸体，并且这些尸体对食腐幼虫变得有毒，这为这个谜题提供了一个可能的解决方案。已经开发了几种实验技术来研究这些现象（例如，尽管有聚集情况仍能定量测定孢子数量、跟踪毒性发展的方案等）。结果表明存在一个循环，包括由于约1000个孢子的δ-内毒素导致幼虫中毒和死亡，B.t.i.在尸体中繁殖到数百万后发芽、营养生长和产孢（并产生毒素）。讨论了这些结果对B.t.i.生态学以及蚊子控制实际应用的影响。
