Variation in termite alate swarming in rain forests of Central Amazonia

Abstract

The swarming of termite a lares (= reproductive forms) in a Central Amazonian tetra firme rain forest (Reserva Floresral Adolpho Ducke) was studied with 2 light traps which were emptied rwice per week and continuously run for 2 years ( 176 sampling intervals). Here, we present the data on variation of swarming events in rhe termite families, in rime and space. Termites were present in 64-83% of all catches, and there was no month without swarming. A total of 25.500 termites of three families W;lS collected. The family Termitidae accounted for 91-98% of the number of individuals recorded per trap and year, 2-8% were Kalorermitidae, and 0.5-2% Rhinotermiridae. Average catch size per trap and month was .3.8 individuals in Rhinorermitidae, 38.4 in Kalorermiridae, and 467.3 in Tcrmitidae; maximum catches were 20, 490, and 5940 individuals per trap and month, respectively. However, the swarming frequency ofTermiridae (45-55% of the sampling intervals) was not higher than that of Kalorermiridae (41-58%); rhe frequency of Rhinorenniridae was low (8-18%). To assess the variation of swarming evenrs with rime, we rested for correlation berween the swarming evenrs (total individual numbers, total numbers for each family, frequency per family and presence/absence for each family) of the 2 traps and of the 2 yc>ars. No correlations could be found . Both traps were only ~ 500 m apart, bur the total annual catch numbers varied considerably between them, which points to large small-scale variation in swarming (Trap !III: 7.500/2.600 individuals in rhe 91-92 period; 4.500/9.700 in 92-93). Also, only 18,32 and 36% of the Rhinorermiridae, Termiridae and Kalorermiridae swarms, respectively, occurred simultaneously in both traps. As termite swarms vary considerably in timing, size and extension, we hypothesize rhar rhe colonization of a determined spot offoresr by a particular termite species is highly unpredictable, which could explain the patchy distribution of termites and the high endemism of termites found in different parr.s of Amazonia. rain forest, Isoptera, termite families dispersion..