The blueberry gall midge, Dasineura oxycoccana (Johnson) (Diptera: Cecidomyiidae), is an important pest of wild and cultivated blueberries, Vaccinium spp. (Ericales: Ericaceae), and causes great loss at infested farms. This is the first report of the occurrence of the pest at a plantation in Mexico. Suspicious larvae and adults were collected from flower and vegetative buds of 12,625 (11.2% of the total) infested blueberry plants, Vaccinium corymbosum L. Specimens were identified based on DNA similarity to known sequences of the mitochondrial COI gene and on traditional morphometric analysis of the species. Interestingly, DNA sequence similarity varied depending upon the origin of known sequences: 98.88-99.84% similarity with D. oxycoccana from V. corymbosum in Canada, Japan, and United Kingdom, <91.04% with specimens from Vaccinium macrocarpon from Canada, and <85.85% with other Dasineura species. In conclusion, both (morphometric and molecular) approaches agreed that all analyzed specimens were D. oxycoccana. Once identified, complete control of the pest was achieved 4 weeks after proper measures were initiated.