OVARIAN INHIBITION AMONG NESTMATES OF <i>EXONEURA BICOLOR</i> SMITH (HYMENOPTERA: XYLOCOPINAE)¹

Abstract

Abstract Overwintering nests of the semisocial bee Exoneura bicolor Smith contain one or 2 inseminated females with enlarged ovaries and a varying number of uninseminated females with small ovaries. By transferring combinations of colony nestmates to artificial nests we show that mated egg‐layers have an inhibitory effect on ovarian development of unmated females. Unmated females which are separated from winter egg‐layers show significant ovarian enlargement within 16 days. This indicates that during winter, insemination and ovarian development are not causally related, but are dependent on other factors such as social dominance.