Initiation of Mass Emergence of a Tropical Chaoborid, Chaoborus (Edwardsops) magnificus (Insecta, Diptera), at New Moon

Abstract

Diurnal and diel emergence patterns of Chaoborus (Edwardsops) magnificus were investigated in a dry season, using two emergence traps set in the center of Lake Dom Helvecio, Southeastern Brazil. This species showed the highest catches up to 95 % of total ones including four Chaoborus species during about one month. It initiated to emerge largely at new moon night. Emergence of this species occurred actively between 3:00 am. and 6:00 am., namely before sunrise. The synchronization of growth of this species under lunar cycle is strongly suggested. The meaning of synchronization in emergence of chaoborids is discussed.