Anthocharis midea (Hubner, 1809)

Opler, Paul A., Stout, Todd L., Back, Werner, Zhang, Jing, Cong, Qian, Shen, Jinhui & Grishin, Nick V., 2022, DNA barcodes reveal different speciation scenarios in the four North American Anthocharis Boisduval, Rambur, [Duménil] & Graslin, [1833] (Lepidoptera: Pieridae: Pierinae: Anthocharidini) species groups, Zootaxa 5194 (4), pp. 519-539 : 532-534

The midea group: speciation without barcode differentiation

Populations of A. midea extend southwestwardly from Connecticut and the Great Lakes states through the eastern and Midwestern United States to northern Florida, the Gulf coast states and Texas to northeastern Mexico (Tamaulipas), while Anthocharis limonea is found in southern Nuevo Leon south along the Sierra Madre Orientale to the states of Puebla and Mexico ( Llorente et al. 1997) ( Figures 27–28 ). The existence of a small population of A. limonea in the Sierra Madre Occidental is shown by the collection of two specimens collected by the late Richard W. Holland in western Durango; these specimens are deposited in the McGuire Center for Lepidoptera, Gainesville, FL.

The voltinism of Anthocharis limonea is uncertain with its flights ranging from mid-June until November depending on the locality and year. The species flies most consistently in September ( Llorente et al. 1997; Back, pers. comm.; Opler, unpublished), but emergence of adults in November resultant from eggs found in September suggest that is bivoltine (Back, pers. comm.). Flights appear to be timed to occur after heavy wet season rains, in particular those associated with hurricanes coming from the Caribbean. We presume there is a pupal diapause broken by the rains which result in a single flight per season, though it is possible that the species could have more than one generation per year at some localities, but this is unknown and remains to be documented.

The two species most likely arose in the past from a common ancestor and a distributional disjunction must have allowed the two species to evolve under somewhat to very different selective pressures. At present, the two taxa’s closest reported occurrences are northern Tamaulipas for A. midea texana and southern Nuevo Leon for A. limonea , a linear distance of 175 kilometers. They differ in the following character states: flight period, geography, habitat, mate location, adult ground color, and adult dimorphism. They are no doubt each other’s closest relatives and may be relatively recently separated, Pliocene—Miocene. Other examples of such vicariant populations or species-pairs are Chlosyne harrisii and C. kendallorum , Papilio glaucus and P. alexiares . [ Papilio palamedes and P. palamedes leontis is an example of disjunct subspecies.]

Figures

FIGURE 27. Distribution of sampled individuals in the midea group. Anthocharis midea—upside down green triangles, Anthocharis limonea—pale blue triangles, erect green triangle—Anthocharis limonea phenotype with Anthocharis midea haplotype.

FIGURE 28. Haplotype array for Anthocharis midea group.