MATING AND NECTAR FEEDING IN THE PSYCHOMYIID CADDIS-FLY TINODES-WAENERI

The psychomyiid caddis fly Tinodes waeneri (L.) mated on a shrub near the shore-line (and the littoral emergence site) and on adjacent flowe rs. Both males and females were shown to ingest nectar, from different species of flowers having open nectaries (mostly of the family Apiace ae). Male fat content was negatively correlated with age (wing wear), indicating that ingested nectar did not restore lipids. Therefore, we presume that nectar was mainly used for mechanical activities (e. g. f lying, walking, mating). A male lost about 7% of his original carbon a nd nitrogen during copulation, suggesting that they had the potential to copulate often. The sex ratio differed between the shrub and flower habitats, and females on flowers were also older and had more frequen tly laid eggs. Thus, females seemed to mate as virgins on the shrub, d eposited their first egg batch, returned to the shore, ingested nectar from the flowers and copulated again. Males on flowers encountered pr oportionally more females, but those females contained on average only 3% of the number of eggs compared with females on the shrub.