Identification of Hypoderma actaeon (Diptera: Oestridae) in red deer (Cervus elaphus) from northern Spain: Microscopy study and molecular analysis.

Hypoderma spp. larvae were observed subcutaneously in the dorsal and lumbar regions of red deer (Cervus elaphus) hunted in the province of León (northwestern Spain) causing a myiasis. They were removed and initially classified by their size, shape, color, and location under the skin into the three larval stages that parasitize these animals. The morphological characteristics of the first and second-instar are described and from the features of the third-instar the species was identified as Hypoderma actaeon. To accurately identify this species, five isolates of genomic DNA from the third-instar, two from the second-instar and two from first-instar of H. actaeon were analyzed by PCR analysis of the COI region of mt-DNA. The results confirmed that the examined samples exactly matched with H. actaeon. This study has shown the morphological identification of the three larval stages of H. actaeon and, for the first time, the first and second-instar larvae have been molecularly characterized. Finally, identification of only H. actaeon suggests that this species is the only affecting red deer in the Iberian Peninsula.