Study On The Control Technique For Dioryctria Rubella By Regulating The Growth Of Pine Shoots

In this paper, several different plant growth substances were sprayed on the shoots of P. massoniana, P. thunbergii, P. elliottii and P. taeda with different concentrations in order to observe their effects on pine shoots growth and volatile substance.To the shoots treated with different plant growth substances,the influence on weight increasing of the larval Dioryctria rubellats, and olfactory response to adults have been also investigated. The control test in the field and safety evaluation test of the growth substances have been considered. The main results were as follows:1. GA3 promoted the shoots length of all pine species significantly. In contrast, the shoots length of P. massioniana,P. elliottiiand P. thunbergii were restrained significantly by PP333 , and the shoots length of P. elliottii and P. taeda were restrained significantly by the complex preparation (C2),in different experiments.2. The volatile substances of P. elliottii and P. massioniana shoots,were obtained by the method of Dynamic head-space. Using GC-MS technique, composition and relative contents of volatile organic compounds were analyzed, respectively.71 compounds from the volatile substances of P. elliottii shoots were identified,and 63 compounds of P. massioniana .42 compounds coexisted in both.3. The influences of the D. rubellat larvae's weight increasing were not obvious compared with control,the larvae were fed with P.elliottii shoots treated with different growth substances.4. The olfactory response of female adults to volatiles of pine shoots were tested with a "Y"-tube olfactometer.The results showed that the control attracted more adults than the volatiles treated with substances(except for PP333).5. The control test in the field showed that it was efficacious in controlling the damage rate of D. rubellat and other pine tip moths.The results of field test was correspond with the results of the growth inhibition tests.PP333and C2 demonstrated best control efficiency of all.6. For 7 different kinds of biennial shoots of P. elliottii (control and the shoots treated with diffrent kinds of substances), there were not significant differences between all the treated shoots and control in basic density, dry matter content,and cellulose content.It indicated that it's a safe method for pest control through regulating the growth of pine shoots.