Agonistic Behavior and Cuticular Hydrocarbon Phenotypes of Colonies of Reticulitermes (Isoptera: Rhinotermitidae) from Northern California

Abstract

Reticulitermes in northern California is supposed to be represented by R. hesperus Banks and R tibialis Banks, yet at least 5 distinct cuticular hydrocarbon phenotypes have been characterized. Three hydrocarbon phenotypes from the Institute of Forest Genetics near Placerville. CA, and 3 cuticular hydrocarbon phenotypes from 2 separate sites in Marin County were used to characterize interactions of foraging groups or colonies at each site. Pairings from the same foraging group or different foraging groups of the same colony rarely resulted in immediate aggression and never resulted in high mortality. Pairings of workers from different foraging groups of the same cuticular hydrocarbon phenotype from either the Placerville or Marin sites resulted in few bouts (8 and 15%, respectively ) with immediate aggression, but after 24 h, mortality was high in 56 and 81% of the bouts, respectively. Pairings from different cuticular hydrocarbon phenotypes resulted in immediate aggression 48.8 and 61.5% of the time, respectively, nearly all of these (>99%) resulted in high mortality after 24 h. These results suggest that these Reticulitermes recognize hydrocarbon phenotypes, and can differentiate colony mates and alien workers within a cuticular hydrocarbon phenotype. Because kin discriminal ion suggests genetic relatedness among individuals, this bioassay will be useful for determining the association of foraging groups in ecological studies of Reticulitermes colonies in northern California and indirectly may indicate relatedness among colonies of the same hydrocarbon phenotype.