C-2-9

OVIPOSITION DETERRING EFFECTS OF QUINOLIZIDINE ALKALOIDSON SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA)

Boguang Zhao and Gary G. Grant
Nanjing Forestry University, Nanjing 210037, P.R. China and CanadianForest Service, P.O. Box 490, Sault Ste. Marie, ON, Canada P6A 5M7


Although alkaloids deter feeding by lepidopteran larvae, few studieshave examined their effects on oviposition behavior of Lepidoptera. Thus total alkaloid extracts and purified quinolizidine alkaloids fromtwo Chinese plants, Sophora alopecuroides and Thermopsis lanceolata,were tested for their effects on the spruce budworm, a tortricid species. In dual choice oviposition bioassays, females preferred untreated ParafilmTMsubstrate to ParafilmTM substrate treated with total alkaloid extractsat doses as low as 1.5 ug/cm2. Of 10 quinolizidine alkaloidstested, 7 significantly deterred oviposition at doses of 7.9 ug/cm2or less, including aloperine, which was deterrent at 0.3 ug/cm2. There was no effect on longevity of males or females continuously exposedto artificial substrate treated with aloperine or total alkaloid extract(S. alopecuroides) nor was the ability of males to inseminate femalesaffected. However, female production of egg masses was significantlyinhibited but clutch size (eggs/egg mass) was not. Spraying 1 mlaliquots of total alkaloid extract (10 mg/ml) from S. alopecuroidesor aloperine (1 mg/ml) on 8 cm twigs of balsam fir, Abies balsamea,deterred spruce budworm oviposition on its host. This is the firstdemonstration of the deterring and inhibiting effects of quinolizidinealkaloids on lepidopteran oviposition.