Primavera porrecta

A new genus, Primavera, is described for Rabdophaga porrecta Felt, a cecidomyiid that forms pouch galls in samaras, the winged fruit of American elm, Ulmus americana...regularly emerges from the soil during the first week of March in Beltsville, Maryland, USA...The only known species [of Primavera] is one of the earliest plant-feeding gall midges to emerge in spring.

Plant tissue rapidly grows around these larvae, enveloping one to several larvae in swellings that are closed but for a tight slit lined with fine white cilia. By early April when the larvae are full-grown, the samaras become flaccid and the swellings open to release the larvae. Most infested ovaries result in undeveloped, malformed samaras...This cecidomyiid has evidently been rarely noticed but is doubtless widespread, as it is known from Wisconsin, New York, West Virginia, and Maryland.

Primavera (new genus) porrecta (Felt), the elm samara midge: description and biological notes (Diptera: Cecidomyiidae)