Mating Behaviour, Fecundity Of Basilepta Melanopus Lef(?)vre (Coleoptera Chrysomelidae) And Its Occurrence Regulation Of Field

Basilepta melanopus Lefevre（Coleoptera:Eumolpidae）is one of the most harmful pests of Camellia oleifera,which has a serious effect on the photosynthesis and the production.The reproductive characteristics,mating behaviour,sexual selection and fecundity of B.melanopus were studied in this article.The results showed that the external morphological characteristics of male are similar to this of female.There is a“V”stripe at the fifth abdominal segments of female,but not“V”stripe at the fifth abdominal segments of male.The growth and development of B.melanopus was affected by temperature.The pupal duration and egg duration were decreased with the increasing temperature,the developmental zero of pupae were 7.5（±1.2）°C and the effective accumulated temperature of the pupae stage was 188.36（±10.7）day degree.The adults mate each other after a sex maturity period,the pre-copulation duration of male 5.5（±0.2）d was shorter than female 7（±0.3）d.The period of mating lasted 1 min at least and 40 minutes at most.And the average of that is 18.88（±9.3）min,and the total duration of mating for most adults was 16-30 min.After having finished mating for 6-7 days,adults began to lay eggs.There is a oviposition peak between May 23^rd and 25^th,more than 82%of the eggs were laid during the first 15days and the mean egg-production of per female was 275.5（±131.4）.Females like to lay eggs on the reversed side of leaves and the bottom of plants.Females tended to choose those males to mate with who are smaller,while males tended to mate with non-virgin females.The mating bahavior happened most frequently at 10:00,and about 40%less at 16:00 and18:00 and the mating behaviour happened at a low level at the rest time;Oviposition activity got to its peak at 16:00 and 18:00,at 14:00,22:00,while at 2:00,the activity was much weaker.Systematic investigations in Camellia oleifera field showed that there were great significant differences between upper part and lower part and insignificant differences existed at horizontal orientation.The fruit size and the damage degree of leaves were decreased with the increasing slope and the number of fruit have no significant differences.In this three samples,the hazard in the sample 1 and sample 2 were worse than that of the sample 3 and the fruit size of sample 1 and 2 were much bigger than that of sample 3.To find out the optimal model through fitting 6 functions to calculate the threshold of mean wormhole number.Those 3 pairs of variables which wormhole number and camellia fruits,camellia fruits and leaf damage degree,and wormhole number and leaf damage degree,fit cubic equations well.Reaching a extreme significant difference（P<0.05）.Based on these mathematical models,the threshold of wormhole number is 5.01 holes per leaf.