Swarming behavior of the economically most important termite, Coptotermes havilandi (Isoptera : Rhinotermitidae), in southeastern Brazil

Some aspects of swarming behavior of Coptotermes havilandi (Isoptera, Rhino termitidae) in southeastern Brazil were investigated. Daily and seasonal Ri ght distribution, frequency, and specific information on the environmental conditions (temperature, relative humidity and precipitation) at the exact time of the swarming events in Sao Paulo City, Brazil, were reported and di scussed. The alate sex ratio was reported during flights in 1997. All the r esults were compared with information in the Isoptera collection labels of the Museu de Zoologia da Universidade de Sao Paulo (MZUSP) during 45 years. Although this species shows a clear peak swarm from August to October (end of winter and beginning of spring), we also observed sporadic smaller swar mings almost all year, A clear lapse in flight behavior occurs only in May/ June (autumn). The peak flying season of C. havilandi can be shown to coinc ide with the beginning of the rainy season. Here, we suggest that swarming be probably controlled by an endogenous biological clock, along with the in trinsic mechanisms (colony-regulating) and extrinsic factors (temperature, humidity, rainfall, etc.). The flight period preferred by C. havilandi in S ao Paulo is around sunset. Nevertheless, we observed swarmings from 3:00 P. M., under high solar incidence, to as late as midnight. Sex ratio of the li ght-trapped alates for 1997 was close to 50:50, although light trap studies may not reflect real sex ratios.