Ant-hemipteran associations in a market-gardening based agro-system in a Yaoundé suburb, Centre Region (Cameroon)

Abstract

Tritrophic plant-hemipteran-ant relationships are poorly documented in tropical African market-garden agro-systems despite its agronomic importance. The present study aimed at characterizing ant-hemipteran associations on five market crop species at Nkolondom (north-western suburb of Yaoundé): Abelmoschus esculentus, Capsicum annum, Solanum lycopersicum, Solanum melongena and Solanum scabrum. From July to October 2013, twice per week, feeding activities of ants were examined and the occurrence of each ant/hemipteran association recorded per plant species. As result, ants preferentially harvested honeydew excreted by hemipterans. However, Myrmicaria opaciventris and Camponotus flavomarginatus also collected plant sap from wounded organs. Among hemipterans, Aphis fabae, Aphis gossypii, Aulacorthum solani, Macrosiphum euphobiae, scale insects and mealybugs were the most recurrent. The most frequent associations were M. opaciventris-A. fabae and C. flavomarginatus-A. fabae on S. scabrum, C. flavomarginatus-M. euphorbiae on S. lycopersicum, C. flavomarginatus-A. solani on C. annuum, M. opaciventris-A. gossypii and Technomyrmex sp.-A. gossypii on S. lycopersicum. Some moderately frequent associations viz. C. flavomarginatus-M. euphorbiae and M. opaciventris-M. euphorbiae were recorded on S. melongena. For these associations, highly significant and positive correlations was raised between ants’ and aphids’ populations, suggesting potential mutualistic interactions between the two taxa.

Keywords: Aphids, bugs, feeding behavior, Formicidae, interactions, market crops.