Pollination of Phyllanthus (Phyllanthaceae) by gall midges that use male flower buds as larval brood sites

Leafflowers (Phyllanthus; Phyllanthaceae) are engaged in obligate mutualisms with leafflower moths (Epicephala) that actively pollinate leafflowers and consume the developing seeds as larvae. Among >1,000 species of worldwide, however, mutualism is considered to be present only roughly half species. Knowledge on pollination biology remaining critical for understanding origin mutualism, but such information thus far limited. We studied two Phyllanthus Japan (P. flexuosus P. liukiuensis) one New Caledonia baladensis); three belong distantly related subgenera share a characteristic dark red floral display. A bagging experiment showed self-incompatible wind hardly plays role pollination. In flexuosus, gall midges genera Clinodiplosis Macrolabis were most consistent abundant flower visitors. They fed nectar at spongy disc male flowers laid eggs buds, picking up pollen contacting styles nearby female process. Infested buds developed into sterile galls, within which midge larvae completed their development. These results indicate pollinated by use larval brood sites. Because infested galls later stage than did Clinodiplosis, likely an inquiline induced Clinodiplosis. Association was also observed liukiuensis baladensis flowers, suggesting occurs least Phyllanthus, contain specialized moths.