Contarinia midge larvae collected from the base of a live oak tree. Plano, TX. ca. March 23, 2011. Identified by Raymond Gagne: Mike, the larvae of your species probably don’t make any gall as such, but live freely sucking sap in the flowers. This may be accompanied by some swelling. I am fairly sure that the adults emerged and laid their eggs shortly before the catkins opened. Once the larvae have fed, which may take only a few days, they’re gone until next year. The larvae diapause in the soil and pupate the following spring. The biology is well calibrated. Here in Maryland, a gall midge that lives in developing seeds of elm come out every year the first week of March when the buds are burgeoning willy-nilly. Some years the ground is frozen or there is a gale blowing and the population does not do well. A reference for that one: Gagné, R.J. 2002. Primavera (new genus) porrecta (Felt), the elm samara midge: description and biological notes (Diptera: Cecidomyiidae). Annales de la Société Entomologique de France 38: 39-44.