ANTIFEEDANT AND GROWTH-INHIBITORY EFFECTS OF THE LIMONOID TOOSENDANINAND MELIA-TOOSENDAN EXTRACTS ON THE VARIEGATED CUTWORM, PERIDROMA-SAUCIA (LEP, NOCTUIDAE)
W. Chen et al., ANTIFEEDANT AND GROWTH-INHIBITORY EFFECTS OF THE LIMONOID TOOSENDANINAND MELIA-TOOSENDAN EXTRACTS ON THE VARIEGATED CUTWORM, PERIDROMA-SAUCIA (LEP, NOCTUIDAE), Journal of applied entomology, 119(5), 1995, pp. 367-370
Antifeedant and growth inhibitory effects of toosendanin, a limonoid a
llelochemical from the bark of the trees Melia toosendan and M. azedar
ach, were determined for the variegated cutworm, Peridroma saucia, usi
ng different bioassays. Toosendanin significantly deterred feeding of
2nd and 4th instar larvae in diet choice and leaf disc choice bioassay
s, respectively. Refined bark extracts containing 60-75% toosendanin w
ere less deterrent than the pure compound in both bioassays. However,
the 60% extract significantly inhibited growth of neonate larvae in a
dose-dependent manner when incorporated into an artificial diet, with
an EC(50) (concentration reducing growth by 50% relative to controls)
of 42.3 ppm at 7 days. Extracts containing 60% and 75% toosendanin wer
e more inhibitory than equivalent amounts of pure toosendanin in this
chronic growth bioassay, suggesting the presence of other minor consti
tuents which must be significantly more inhibitory, though less deterr
ent to feeding, than toosendanin itself. Nutritional analyses of 4th i
nstar larvae following both oral and topical administration of toosend
anin or the 75% extract confirm that both materials possess a combinat
ion of antifeedant and growth inhibitory properties.