Regeneration and biosynthesis of dytiscid defensive agents (Coleoptera: Dytiscidae)

The defensive secretions of the dytiscid species, Agabus seriatus (Say) and Agabus obtusatus (Say), were qualitatively and quantitatively analyzed by high-pressure liquid chromatography. The intrinsic ability of A. Seriatus and A. Obtusatus to regenerate their prothoracic gland defensive secretions under laboratory conditions was determined by analyzing the secretions every seventh day for five weeks. Both beetles regenerated ∼ 80% of their prothoracic gland components within two weeks. A. seriatus was injected with [4-¹⁴C]cholesterol and after a three-week regeneration period 7.5% of the¹⁴Clabel was found in the steroidal defensive secretion from the prothoracic glands.