The colonization of the Krakatau Islands by fig wasps and other chalcids (Hymenoptera, Chalcidoidea)

Abstract

This paper describes aspects of the chalcid fauna of the Krakatau Islands in relation to recolonization and floral succession. Chalcids of the family Agaonidae (fig wasps) are the obligate pollinators of fig trees ( Ficus spp.). The years 1984-86 appear to have spanned a critical period in the colonization of Anak Krakatau by Ficus and its associated animals. Within this period, flowering and successful pollination have taken place for the first time and the diversity of fruit-eating vertebrates has multiplied. The chalcids present on Anak Krakatau were compared with those found on other islands in the group. The chalcid fauna of Anak Krakatau had most in common with that of the spit area of northern Sertung, with which it shares a Casuarina -dominated vegetation. Comparisons between chalcids collected by similar methods on the Krakatau Islands and in tropical West Africa indicated that at the family level the faunas are remarkably similar.