Abstract: When adult Apriona germari was fed with twigs of Broussonetia papyrifera treated with a dose of 1.0　μg／mm2 of thermopsine and cytisine respectively, thermopsine showed no feeding deterring effects and cytisine showed significant feeding deterring effects. With the same dose, both two alkaloids caused the longicorn bettle to reduce oviposition and egg hatching significantly without their death, When A. germari was fed with twigs of B. papyrifera  treated with the doses of 8．0×10－2，4．0×10－2，2．0×10－2，1．0×10－2，5×10－3 μg／mm2 of neem extracts (Containing azadirachtin 10％） respectively, the first two doses caused 100％ mortality, the dose of 2．0×10－2 μg／mm2 led 80％ mortality and completely inhibition of oviposition, the last two doses led 30％ and 0 mortalities respectively and radical reduction in oviposition and egg hatching. This is the first report of the reduction effects of quinolizdine alkaloids on oviposition and egg hatching in Insecta, also of the inhibiting effects of neem extracts on oviposition and egg hatching in Cerambycidae.