Stusies on the effect of trehalase inhibitors on insects and their possibility as a insect control agent.

点击翻译按钮获取中文摘要

It is expected that the inhibition of trehalase which hydrolyzes trehalose gives severe effect on insect life, because insects utilize the haemolymph trehalose for their energy source. In the present studies, we observed the effect of a specific and potent trehalase inhibitor, validoxylamine A (VAA) on insect physiology and elucidated the mechanism of VAA action. And then, potency of VAA as a insect control agent was investigated.In Lepidopterous insect larvae (Mamestra brassicae, Spodoptera litura), VAA treatment at the early stage of the final instar evoked the relaxation of segmental muscles, decrease of the pulsation of dorsal vessel, etc. And at pupation, the insects died of incomplete pupal development. ^1H-and ^<13>C-NMR analysis of the nutrients of treated larvae showed that trehalose metabolism decreased by trehalase inhibition in insect tissues and that strong effect appeared at the stage when most of tissues needed great amount of energy source for their reconstruction for pupationIn insects which utilize mainly trehalose for their flight energy (Periplaneta americana, Musca domestica, Boettecherisca perigrina), VAA treatment apparently reduced flight activity. Their muscle trehalase activity was indicated to be inhibited by VAA.However, the flight of some species which were able to utilize lipids as well as carbohydrates for the energy (Locusta migratoria, Calliphora nigribarbis) was not affected by VAA treatment, though the trehalose metabolism was suppressed as other insects.Strong effect of VAA on the reproduction of the locust was recently observed. Taking these results into account, trehalase inhibitors were concluded to be one of the candidates for specific insect control agents. VAA itself, however, has very low permiability to insect cuticle, and so, practical usage was not expected. Some chemical modification to give the permiability have not yet produced appropriete chemicals.