Preliminary Studies On Aggregation And Mating Behavior Of The Forest Borer, Batocera Horsfieldi (Hope) (Coleoptera: Cerambycidae)

Batocera horsfieldi (Hope) is a kind of polyphagous woodworm pest with large-scale. It is difficult to control for the characteristics of hidden life and strong resistence. Therefore, they become the main destructive pest to many kinds of natural forests, economy trees and urban garden trees, cost great losses of the economy and ecology in China. Nowadays, the main method of preventing B. horsfieldi is always by mankind with low-efficient or chemical means. By contrast, less researches refered to the information communication mechanisms between B. horsfieldi male and female adults. In order to development of high-activity attractants, mass-trapping, centralize-processing of adults, and establishment of the sustainable control system of B. horsfieldi initially, it is important to study the chemical information communication mechanism between B. horsfieldi male and female adults based on chemical ecology. The results are summarized as follows:1. Aggregation and mating behavior of the forest borer, B. horsfieldi was observed both in the laboratory and field. The results showed that: 1) Adults aggregating on the trees that are the host plants, feed on the phloem of branch; 2) Contact sex pheromone should be accumulated on the body of female B. horsfieldi. Males differentiated between sexes by touching. When male and female of B. horsfieldi encountered, the male was observed to approach or hold the female only when he touched her with his antennae. The male was observed to hold and mount the female, during holding and mounting, the male frequently touched the female elytra and pronotum with his labipalpi and maxipalpi, and then to bend his abdomen toward her abdominal tip, ejaculation sequentially; 3) The host plants had evident influence on mating behavior of B. horsfieldi. When adults mating on the host plants, duration of mating behavior is significantly longer than the one which mating in the clearing, and the efficiency of mating is significantly increase.2. The extracts from females were tested, checks up the adults' induction tropism and behavior reaction to the odor or flavour trail of the male. The results are as follows: The distinguishing and estimation abilities of B. horsfieldi adults' olfaction without contacting are not the leading factors to look for the mates. The mating action of adults generally started by touching. The sex pheromone of female adults is a contacting pheromone. The male adults receive the signal stimulation by the contacting inductor of the chemical inductors on the antennae, labipalpi and maxipalpi.3. The external morphology of antennal,labialpalpus and maxillarypalpus sensilla was observed by SEM. Eight types of antennal sensilla and four types of labipalpi and maxipalpi sensilla were found. There are diferences in number, type and location of antenna senilla between male and female. But only in number of labialpalpus and maxillarypalpus senilla. Chaetic sensilla was considered to be a mechanoreceptor. Basieonie sensilla and Trichodea sensilla were considered to be olfactory receptors. Colpate basieonie sensillum and Styloconic sensillum might be a sensor of contact chemicals.