Canadian Forest Service Publications

Effect of mating on plasma juvenile hormone esterase activity in females of Choristoneura fumiferana and C. rosaceana. 1996. Cusson, M.; Delisle, J. Archives of Insect Biochemistry and Physiology 32: 585-599.

Year: 1996

Issued by: Laurentian Forestry Centre

Catalog ID: 16705

Language: English

Availability: PDF (request by e-mail)

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We measured juvenile hormone esterase (JHE) activity in the plasma of virgin and mated Choristoneura fumiferana and C. rosaceana female moths. In these two species, JH III acid was the only measurable product of in vitro JH III degradation in the plasma. Rates of JH III ester hydrolysis were generally higher in C. rosaceana than in C. fumiferana, but followed a similar pattern in both species, with high activity measured on day 7 of the pupal stage, the lowest activity measured at emergence, and a subsequent increase observed between days 0 and 1. Mating on day 0, in both species, brought about a significant increase in JHE activity on day 1, relative to virgins. On days 3 and 5, rates of JH degradation did not differ between virgin and mated females. The mating-induced increase in JHE activity on day 1 was not the result of a decrease in blood volume in mated females relative to virgins. Fluctuations in JHE activity did not appear to depend on changes in plasma protein concentration. In both species, topical application of JH 1 or methoprene, on the day of emergence, resulted in dose- and time-dependent increases in JHE activity relative to controls.