Factors that affect aggression among the worker caste of Reticulitermes spp. subterranean termites (Isoptera : Rhinotermitidae)

Aggression was observed among both inter- and intraspecific combinations of four colonies of Reticulitermes flavipes (Kollar) and Reticulitermes hagen i Banks in laboratory assays each month for 4 consecutive months. Termites were most frequently aggressive toward colonies of a different species. Num ber of individuals that displayed aggression decreased over the study perio d, from April to July. There was a slight trend toward reduced aggressive b ehavior as termites were maintained in the laboratory for 3 months. Passive and aggressive individuals were identified and reexamined for display of a ggressive or passive behavior toward nonnestmates. Eighty-nine percent of p reviously aggressive termites displayed aggression a second time. Eighty-ei ght percent of previously passive termites were passive upon reexamination, Differences in head capsule size between passive and aggressive individual s provided no correlation between the presence of aggressiveness and the he ad capsule size in the worker caste.