CHEMICAL ECOLOGY OF INSECT DEFENSE CHEMICALS AGAINST ENVIRONMENTAL MICROORGANISMS

结果表明，在已报道的62种防虫化学物质中，有32种化学物质对琼脂培养基中培养的7种常见真菌具有或多或少的抑菌活性。对燕尾蝶幼虫的防御作用最有效的化学物质是马铃酸，对拟甲虫和甲甲虫的防御作用最有效的化学物质是苯醌类，而大多数脂肪族烃类没有或较低的活性。此外，研究人员还观察到，一种名为Rodolia limbata的雌性臭虫的有机溶剂提取的幼虫提取物可以抑制这些真菌的生长，这种臭虫具有防御天敌的分泌物。但是，在未被发现为防御性分泌物的点锦蛾、家蝇和hircothea幼虫提取物中没有发现明显的抗真菌活性。然而，这三种昆虫的己烷提取物对6种真菌有轻微的活性，这表明这些昆虫可能也有一些防御真菌攻击的化学物质。这些结果强烈提示昆虫防御化学物质可能对作为昆虫天敌的环境微生物有效。

This work showd that of 62 chemicals which have been reported as insect defense substances, 32 chemicals have more and less antifungal activites agaist 7 species of common fungi which were cultured in an agar medium. The most effective chemicals were aristrochic acid as defense substance of swallowtail butterfly larvae and benzoquinones of tenebrionid or carabid beetles, but most of aliphatic hydrocarbones were not or less active. And also larvral extracts with organic solvents of a lady bug, Rodolia limbata which have defensive secretions against their predetory enemies, were observed to inhibit growth of these fungi. But no prominent antifungal activies were found in larval extracts of Conogethes punctiferalis, Musca domestica and Pascothea hiralis, which have not been known their defensive secretions. However, hexane extracts of these three insects were slightly active agaist 6 species of fungi tested, suggesting a possibility that these insects also have some chemical agents for defensing fungal attack.These results were strongly suggestive in that insect defense chemicals may be effective agaist environmental microorganisms as a natural enemy of insects.