| Semanotus bifasiatus (Matsch) is one of the serious stem borers onPlatycladus orientalis(Linn). In this thesis, biological characters of Semanotusbifasiatus is studied. Two methods including steam distillation and Soxhletextraction to exract volatile from Platycladus orientalis are introduced. Theattractive activity of two kinds of extracts and scraps of P. orientalis isresearched by biological determination. Composition of them is studied byGC-MS. The results are following:1. Biological characters of Semanotus bifasiatusSemanotus bifasiatus reproduces one generation each year andoverwinters as adult. The most suitable temperature for adult to come out isfrom 15～20℃, the peak period is from 10th Mar. to 22nd Mar., female's islater than male's for two or three days. The sex ratio is 1:1.12. The adult beginto lay eggs 2~3 days after copulation without nutritious complement. 9~137eggs can be laid by each female, the mean is 72.54±22.13. Life of adult withcopulation is longer than those without copulation. The oviposition period is13.75±2.82 days and the hatching percentage is 87.25%,the developmentthreshold of eggs is 11.43±1.15℃, and the thermal constant is 91.38 DD. Thelarva pupate in early September and the percentage of pupation is90.28%,pupa stage lasts 8～21days, the pupa become to adult at lateSeptember and the percentage of eclosion is 88.16%.2. Extraction of volatileThe yield rate of steam distillation and Soxhlet extraction are 0.23%and2.36% respectively. The latter is higher than the former obviously.3.Bioassay of volatiles to Semanotus bifasiatus"Y"-tube olfactometer: Semanotus bifasiatus shows great tendency toboth essential oil extracted by steam distillation and oddments of P. orientalis,the rate of choice are 66.7%and 58.3%, the former is higher than the latterobviously. It shows no tendency to essential oil extracted by Soxhlet extraction.Female shows greater tendency than male.
|
PDF Full Text Request