Male genitalia of Erynnis baptisae and Erynnis lucilius

Photo Galleries: Three Dimensional Lepidoptera Genitalia Photo Gallery: Rhopalocera

Comparison of male genitalia images for exemplar voucher specimens of Erynnis baptisae and Erynnis lucilius

Version 2016.1 by Hugo Kons Jr.

Genitalia were dissected and images taken by Hugo L. Kons Jr. with the GT Vision imaging system at the former American Entomological Institute. All structures are the natural three dimensional shape (not slide mounted).

Preliminary analysis of a few specimens of Erynnis baptisae from Virginia and Wisconsin and a few Erynnis lucilius from Wisconsin suggests the two species may be separated from the structure of the vesica. However, no diagnostic features of the capsules were clearly apparent from this sample, with both species exhibiting infraspecific variation in valve shape, such as the length of the posterior processes. The E. baptisae sample included specimens from suburban Alexandria, Virginia, outside of the range and habitat of E. lucilius. Further investigation is needed to more thoroughly assess geographic and infraspecific variation before this potential interspecific vesica difference can be regarded as definitive.

Erynnis baptisae (left) Erynnis lucilius (right)

Phallus apex with vesica everted

The terminal diverticulum of the vesica (red arrow) is narrower in the baptisae specimens than in the lucilius specimens. Note the ductus ejaculatorius (purple arrows) is everted in the baptisae but not in the lucilius; this is NOT a difference between these species.