Temporal profiles of juvenile hormone titers and egg production in virgin and mated females of Heliothis virescens (Noctuidae)

Abstract

Juvenile hormones (JH) I, II, and III were monitored in hemolymph of virgin and mated females of various ages in Heliothis virescens. JH I was the predominant homologue followed by JH II, but JH II was present at a higher level in young virgin females. JH III was detectable only at a low level. In virgin females, hemolymph JH titers were low at emergence (2.2 ng/ml-total amount of JH I and JH II), but increased thereafter and reached a maximum at 24 h of age (53.5 ng/ml). At 30 h and 36 h of age, JH titers dropped to a low level, but increased again in older virgin females. After mating, JH titers increased significantly. JH titers at 0 h after uncoupling (137.4 ng/ml) were nearly 3 times as high as those in 24-h-old virgin females. Within 6 h after uncoupling, JH titers decreased slightly, but titers increased with age of mated females and reached a level of 320.2 ng/ml hemolymph at 72 h after uncoupling. The titer of JH I and JH II was correlated highly with total number of eggs produced ( r 2=0.70, P<0.001). Mating stimulated JH production, resulting in an increase in egg production.