Effect of rain and temperature on the nocturnal flight phenology of Afrotropical ants (Hymenoptera: Formicidae).

Abstract

The effects of rainfall and temperature on the seasonal phenology of ant nuptial flights in a forest locality in Ghana was studied for 42 months using a light-trap. A total of 204393 ants was caught. Of the 135 species/morphospecies collected, 40 could not be identified beyond genus, and males of a further 14 beyond subfamily. The commonest 65 species/morphospecies flew a mean of 10.1 ± 0.4 months per year. With the exception of males of Dorylus atriceps, Platythyrea conradti, Plat. modesta, Crematogaster nr striatula plus gynes of Plagiolepis brunni and Cr. [F257], whose peak flights occurred in the main dry season, flight activity coincided with the onset of the rainy seasons. Both sexes of Pheidole megacephala, P. speculifera, Tetramorium aculeatum, and Paraparatrechina albipes plus gynes of Cr. striatula and males of Anochetus africanus, Hypoponera dulcis, Cr. kneri, and T. guineensis flew more frequently on rainy than dry dates. Nineteen species were caught more frequently on dry than on wet dates including most Camponotus, Tapinoma, and Technomyrmex spp. Fifteen species/morphospecies responded positively to increasing monthly rainfall, six to increasing monthly temperatures, and five to the interaction between these factors, with males of A. pellucidus, H. dulcis, and Cr. striatula caught more frequently in wetter, warmer months, and those of Camponotus olivieri and Technomyrmex andrei in drier, warmer ones.