Artocarpus (Moraceae) - Gall midge pollination mutualism mediated by a male-flower parasitic fungus

A previously undescribed pollination system involving a monoecious tree spe cies, Artocarpus integer (Moraceae), pollinator gall midges, and fungi is r eported from a mixed dipterocarp forest in Sarawak, Borneo. The fungus Choa nephora sp. (Choanephoraceae, Mucorales, Zygomycetes) infects male inflores cences of A. integer, and gall midges (Contarinia spp., Cecidomyiinae, Dipt era) feed on the fungal mycelia and oviposit on the inflorescence. Their la rvae also feed on the mycelia and pupate in the inflorescence. The gall mid ges are also attracted by female inflorescences lacking mycelia, probably d ue to a floral fragrance similar to that of male inflorescences. Because of the sticky pollen, dominance of Contarinia spp. in flower visitors, and po llen load observed on Contarinia spp. collected on both male and female inf lorescences, Artocarpus integer is thought to be pollinated by the gall mid ges. Although several pathogenic fungi have been reported to have interacti ons with pollinators, this is the first report on a pollination mutualism i n which a fungus plays an indispensable role. The pollination system descri bed here suggests that we should be more aware of the roles fungi can play in pollinations.