EFFECT OF NONSTEROIDAL ECDYSTEROID AGONISTS ON ECDYSTEROID TITER IN SPODOPTERA-EXIGUA AND LEPTINOTARSA-DECEMLINEATA

Citation
G. Smagghe et al., EFFECT OF NONSTEROIDAL ECDYSTEROID AGONISTS ON ECDYSTEROID TITER IN SPODOPTERA-EXIGUA AND LEPTINOTARSA-DECEMLINEATA, Journal of insect physiology, 41(11), 1995, pp. 971-974
Citations number
23
Categorie Soggetti
Entomology
ISSN journal
00221910
Volume
41
Issue
11
Year of publication
1995
Pages
971 - 974
Database
ISI
SICI code
0022-1910(1995)41:11<971:EONEAO>2.0.ZU;2-5
Abstract
In control last-instar larvae of Spodoptera exigua, and Leptinotarsa d ecemlineata, major hemolymph ecdysteroid peaks appeared around day 3-4 , and 8-9, respectively, which is correlated with normal apolysis. Lat er on, hormone titers declined to a basal level, In Colorado potato be etle last-instars, a small rise was noted around day 4, which represen ts the time of digging, In last-instar larvae of S. exigua treated wit h either RH-5849 or tebufenozide, the ecdysteroid titer remained at a basal Level without any elevation, Such larvae showed signs of untimel y apolysis within 12-24 h after treatment followed by cessation of fre sh weight gain, Likewise, hemolymph ecdysteroid levels and larval weig ht gain were reduced in last-instar larvae of L. decemlineata treated with RH-5849 as compared with controls, Otherwise, treatment of Colora do potato beetle larvae with tebufenozide caused no hormonal and physi ological abnormalities as compared with controls, It is suggested that both nonsteroidal ecdysteroid agonists act via ecdysteroid receptor b inding without an increase in ecdysteroid titer.