ACE Inhibitor Captopril Reduces Ecdysteroids and Oviposition in Moths

: By using the selective ACE inhibitor captopril, we studied the effect of the angiotensin converting enzyme (ACE) on larval growth, metamorphosis, and reproduction in a lepidopteran species, the cotton leafworm, Spodoptera littoralis. Captopril was detrimental to adult formation and oviposition, and in female moths it elicited decreasing ecdysteroid levels, but increasing trypsin activities. Our results suggest that captopril downregulates oviposition by two independent pathways. Apparently, oviposition is influenced by a complex interaction of ACE, trypsin activity, and ecdysteroid levels.