Nestmate discrimination in the harvester termite Hodotermes mossambicus

Summary

Nestmate discrimination was studied in the African harvester termite Hodotermes mossambicus in trophallactic feeding experiments. The results show that Hodotermes mossambicus is able to discriminate nestmates from non-nestmates, feeding nestmates significantly more than non-nestmates. Experiments in which termites were treated with the antibiotic tetracycline for 48 hours and then used either as donors or as recipients in the trophallactic assay indicate that the degree of similarity in the intestinal flora strongly affects nestmate discrimination. Antibiotic-treated termites were fed more frequently by treated non-nestmates than by untreated nestmates. Pairs of non-nestmates, which were both treated with the antibiotic, exchange food as frequently as untreated nestmates. Pairs of nestmates, on the other hand, out of which only one animal was treated, exhibit nearly as little trophallactic contacts as the non-nestmate controls. The results parallel similar recent results in Reticulitermes speratus and indicate that termites can make use of recognition cues which are quite different from those of social hymenopterans, cues that are produced by intestinal symbionts.