New Host Record, New Range Information, and a New Pattern of Voltinism: Possible Host Races Within the Holly Leafminer Phytomyza glabricola Kulp (Diptera: Agromyzidae)

The agromyzid leafminer Phytomyza glabricola is reported from the holly Ilex coriacea, a plant not previously reported to host leafminers. The known geographic range of P. glabricola is extended to include Alabama, Florida, Mississippi, North Carolina, and South Carolina. In these areas, it can be found feeding on sympatric populations of its hosts I. coriacea and I. glabra. Phytomyza glabricola reared from I. coriacea are univoltine, having only a single generation a year, while on I. glabra this species is multivoltine with at least two generations a year. This suggests that either this leafminer exhibits a high degree of host-associated phenotypic plasticity in life history or that host races are present.