Size and protein content of accessory glands in adult male Caloptilia fraxinella in different physiological states

Abstract

AbstractReproductive diapause is a strategy employed by some insects to coordinate reproduction with the appropriate environmental conditions for mate location and offspring development. Male Caloptilia fraxinella Ely (Lepidoptera: Gracillariidae) eclose in July in reproductive diapause, and remain unmated until May of the next year, when they emerge from overwintering sites in a reproductively active state. The present study assesses characteristics of male sex accessory glands (SAG) throughout the adult life stage when males are reproductively active and in early and late reproductive diapause. Male SAG are longer and positively correlate with moth body size when males are reproductively active in the spring compared with males in reproductive diapause in the summer and autumn. Male SAG also contain significantly more protein during the period of reproductive activity than during reproductive diapause. Access to a carbohydrate nutrition source does not impact male SAG length or protein concentration when males are reproductively active in the spring. Treatment with a Juvenile Hormone analogue in the autumn, but not the summer, tends to increase the total protein concentration compared with that of untreated control moths.