Fig Wasps (Hymenoptera: Chalcidoidea: Agaonidae, Pteromalidae) Associated with Asian Fig Trees (Ficus, Moraceae) in Southern Africa: Asian Followers and African Colonists

Abstract

The Asian and Indo-Australasian fig tree species Ficus microcarpa and F. religiosa are widely-planted street and garden ornamentals in southern Africa and elsewhere. Like other fig trees, they depend for pollination on host specific fig wasps (Agaonidae). Their pollinators have also been widely introduced, and this allows the trees to become naturalised weeds. Both trees also support numerous non-pollinating fig wasps that can reduce seed or pollinator numbers, and a sub-set of these assemblages also now have wide distributions outside their native range. Two South African pollinators (Elisabethiella baijnathi, E. stuckenbergi), a galler (Otitesella uluzi) and a parasitoid (Sycoryctes species) occasionally succeed in reproducing in the figs of F. microcarpa, but in very small numbers. The tree's usual pollinator is absent but three Asian gallers of F. microcarpa are now widely established (Odontofroggatia corneri, Odontofroggatia galili and Walkerella microcarpae), and a fourth native species has expanded its host range and is developing as a parasitoid of the Odontofroggatia species (Sycophila punctum). In contrast, the Asian pollinator of F. religiosa (Platyscapa quadraticeps) has colonised South Africa and Zambia and is likely to be present throughout southern Africa. No non-pollinator associates have been recorded in the region. Without its usual pollinator, F. microcarpa cannot reproduce, but F. religiosa may eventually become established in areas with a suitable climate.