Studies on the Ana tom ica l Structure of Ov ipositor and theGnawing Nidus and Ov iposition Habits of Female Adult Apriona ge rm a ri

The p rocess of oviposition behavior of Apriona germ ari includs 4 successive phases: searching a p lace foroviposition, gnawing a nidus, oviposition and blockading the nidus. At the beginning of the gnawing nidus, the female adult turned its head downwards, gnawed“川”-shaped shallow groove , then gnawed a deep oval groove bellow. After the niduswas established, the female adult laid an egg into the crack on the bottom of deep groove andblockaded niduswith secretion and bark detritus. A finished niduswas app roximately“U”shape with a tilt on themiddle of the bottom. The mean length of ovipositorwas 14. 28 ±1. 91 mm. There were a lot of sense hairs on valvulae. The mean size of niduswas as follows: length 13. 78 ±1. 75 mm, width 6. 94 ±0. 99 mm. There were a p ronounced linear correlation between nidus’width and the diameter of host branch aswell as the nidus’width and thethickness of xylem. Moreover, the linear correlation of the dep th of nidus and the thickness of xylem was also veryconsp icuous. The difference of length and width between the niduswith orwithout eggwas not consp icuous. But thenidus without egg was not deep enough for female adult to lay egg.