The pollinator wasp larvae develop in the fig flowers and then hatch out inside the fig fruits where they mate before dispersal. Figs and their pollinators are thus mutually reliant and form a classic example of coevolution. A recent molecular phylogenetic study shows that they share a long history of cospeciation. I am constructing molecular phylogenies of pollinator and parasite genera to investigate this issue. Fig wasps also show tremendous variety in their sex ratios and mating patterns.
Many species show strong sexual dimorphism, having winged females and highly derived wingless males.
The wingless males are also very varied. Some possess huge jaws which they use in lethal combat with other males when they compete for matings . Others are dwarf forms that crawl into fig flowers and mate with females before they even emerge . The insect larva causes the host plant to produce a novel structure known as a gall. The diversity of Andricus galls is in stark contrast to a notable lack of morphological characters for the wasps themselves.