Anthophora squammulosa Dours, 1870

Orr, Michael C., Koch, Jonathan B., Griswold, Terry L. & Pitts, James P., 2014, Taxonomic utility of niche models in validating species concepts: A case study in Anthophora (Heliophila) (Hymenoptera: Apidae), Zootaxa 3846 (3), pp. 411-429 : 420-421

Anthophora squammulosa Dours, 1870

Anthophora squammulosa Dours, 1870: 78 (lectotype: female, “Mexique”; Muséum national d'Histoire naturelle, Paris, France) (New Lectotype Designation)

Anthophora usticauda Cockerell, 1912: 22 (lectotype: female, Antigua, Guatemala; National Museum of Natural History , Washington, D.C., USA) (New Synonym)

Anthophora usticauda cinerior Cockerell, 1949: 470 (holotype: female, Antigua, Guatemala; National Museum of Natural History , Washington, D.C., USA, USNM Type No. 58873) (New Synonym)

Anthophora franciscana Cockerell, 1949: 470 (holotype: female, San Francisco finca, Zamorano Valley, Honduras; National Museum of Natural History , Washington, D.C., USA, USNM Type No. 58874) (New Synonym)

Anthophora zamoranella Cockerell, 1949: 471 (holotype: male, Zamorano, Honduras; National Museum of Natural History , Washington, D.C., USA, USNM Type No. 58875) (New Synonym)

Anthophora bispinosa Cockerell, 1949: 472 (holotype: male, San Francisco finca, Zamorano Valley, Honduras; National Museum of Natural History , Washington, D.C., USA, USNM Type No. 58877) (New Synonym)

Diagnosis. Male Anthophora squammulosa and A. curta can be separated from other species of New World A. ( Heliophila ) by the apically truncated medial projection of T7. It is distinguished from A. curta with the above couplet and additional characters given in the A. curta male diagnosis.

Females of A. squammulosa are separated from other New World A. ( Heliophila ) based upon the following character combination: basal bands of black setae on the metasomal terga; the lack of strongly curved or bent setae on the galea; the supraclypeal light maculation present, although sometimes reduced to a dot; the near-flat distal edge of the basitibial plate; the clear presence of appressed, branched setae on T5; the very narrowly transparent apical rim of T4; and the relatively flat clypeus, which does not appear fully half-circular in ventral view. From A. curta , it is distinguished using the couplet above and additional characters given in the A. curta section above.

Geographical and ecoregion distribution. This species is found throughout much of central Mexico, scarcely farther north than the Trans-Mexican Volcanic Belt, and ranges south in Central America as far as Nicaragua. Its northern limit appears to be near the southern tip of the Mexican state of Sinaloa, eastward to at least the southern tip of Zacatecas. Collection records are limited (72 unique locations) and consequentially its distribution and habitat requirements are less clear. This species is known from four WWF biomes spread across 20 ecoregions. The Tropical & Subtropical Dry Broadleaf Forests biome is most represented in collection events of A. squammulosa , with 64% of all events made in eight ecoregions. An additional 18% of all collection events took place in the four ecoregions comprising the Tropical & Subtropical Coniferous Forests biome. The remaining 18% of collection events are in the Desert & Xeric Shrublands and Tropical & Subtropical Moist Broadleaf Forest biomes. Overall, this species appears most prevalent in forested environments, although a greater number of collection events are necessary to get a good picture of its abundance in poorly sampled ecoregions.

Phenology. Throughout its range, A. squammulosa is active from August to March. There does not appear to be a significant phenological trend for this species, because flight time varies widely at both the northern and southern limits of its range. At the north end, collections exist from Sinaloa and Zacatecas in both October and March. To the south, it has been collected in Nicaragua and Honduras from October and February. Although there is no overall geographical trend in phenology, A. squammulosa does appear to be most common from September through November, during which 73% of all collection events have taken place.

Floral hosts. There are only 17 floral records for A. squammulosa . It is likely a generalist, as is the closely related A. curta , based on recorded visitation of three plant families despite only being known from six genera. The known floral records for A. squammulosa are:

Araceae : Zantedeschia aethiopica ; Asteraceae : Anthemis sp. , Bidens aurea , Cosmos sulphureus , Melanthera nivea ; Fabaceae : Dalea foliolosa var. citrina .

Comments. This species is unique among the New World bees of the subgenus Heliophila in several ways. It is the only species which has setae in the first submarginal cell and one of only two species in which the male has a single, apically truncated medial projection on T7. It is also the only species in the Neotropics. In Guatemala and Honduras, nearing the southernmost reaches of the distribution of A. squammulosa, Cockerell (1912, 1949 ) described five taxa: A. bispinosa , A. franciscana , A. usticauda , A. usticauda cinerior , and A. zamoranella . All of these entities are synonyms of A. squammulosa based upon examination of the types housed at the US National Museum in Washington, D.C. The lectotype of A. squammulosa was chosen for specimen quality (intactness) and visibility of characters. The labels of the lectotype read as follows (each label separated by a semicolon): “12. ♀ Sh; mex 63 Sich; 16 ♀; squammulosa Sich. 16 ♀ 19 ♂ 63 mex.” It should be noted that Brooks (1988) examined a specimen of “ A. squammulosa ” in the Berlin Museum from Guayaquil, Ecuador and concluded that it was likely mislabeled. We have not studied this specimen but at present this is the most reasonable conclusion, given its absence in extensive collections in Costa Rica and its apparent absence from Panamá ( Griswold et al., 1995). No Anthophora were included in the account of the bees of Panamá nor have any been found in more recent material ( Michener, 1954).