Possible Function of Norharmane in Egg-Laying by Ergatoids and Nymphoids of the Lower Termite, Reticulitermes speratus (Kolbe)

摘要

The aromatic -carboline norharmane, which is located in the fat body of Reticulitermes speratus, stimulatedthe activity of juvenile hormone epoxide hydrolase (JHEH) of larva, ergatoid, and nymphoid homogenates. JHEH activityof ergatoid (16.67 ± 1.30 μU/termite) and nymphoid (20.94 ± 1.64 μU/termite) homogenates fortified with 0.1 mMnorharmane was significantly higher than that of ergatoid (9.84 ± 1.69 μU/termite) and nymphoid (16.99 ± 0.60μU/termite) homogenates to which no norharmane was added. Egg-laying by ergatoids and nymphoids, which ingestednorharmane by feeding on norharmane-treated filter paper, was observed in 3 weeks. During rearing on filter paper withoutnorharmane, egg-laying by ergatoids was observed in 5 weeks, whereas no egg-laying by nymphoids was observedthroughout the incubation period of 8 weeks. Norharmane seems to be involved in egg development of ergatoids andnymphoids of R. speratus.