Angiopolybia xanthopus

Andena, Sergio R., Noll, Fernando B., Daza, Mario N. & Carpenter, James M., 2024, The phylogeny of the species of the genus Agelaia Lepeletier, 1836, one of the basalmost groups of Epiponini, with notes on male genitalia (Hymenoptera: Vespidae; Polistinae), American Museum Novitates 2024 (4009), pp. 1-48 : 17-18

THE XANTHOPUS GROUP

The xanthopus group has tergum I subparallel after the spiracles (char. 60:1), which are projected (char. 61:1). The basalmost A. xanthopus is easily recognized by the pronotum with a fovea lying in a deep hollow, bounded anteriorly by the strongly raised and curved prominence ( Richards, 1978: 249). Richards (1978) subdivided this species into two subspecies: A. xanthopus xanthopus , which has yellow markings, and A. xanthopus melonotica , which is blackish brown with only the legs partly yellow ( Cooper, 2000). The pronotal fovea of the clade ( A. nebularum + A. yepocapa ) + ( A. baezae + A. cornelliana ) is in a shallow concavity (char. 26:1), and the posterior margin of the head in dorsal view is at the same level as the eyes (char. 24:1).

The grouping of A. cornelliana + A. baezae was expected. Richards (1943) had divided the A. cornelliana into three subspecies: A. cornelliana cornelliana , A. cornelliana subterranea , and A. cornelliana baezae . In 1978, Richards (p. 242) raised the subspecies baezae to species rank, stating that “this species differs from S. cornelliana in its stronger pronotal keel, broader less acutely pointed tegula.” Cooper (2000: 193) identified variation in the pronotal carina and tegula in the species of A. baezae . He stated: “I would be disposed, therefore, to consider A. conrelliana and A. baezae as a single species showing latitudinal variation. On the other hand, the specimens from the Pastaza Valley indicate that there could be more than one species occupying different altitudes in the Andes.” The specimens of A. cornelliana and A. baezae we saw in this work match the variations cited by Cooper (2000), however, we had in hand only one specimen of A. baezae from Pastaza Valley, which makes a more detailed comparative analysis difficult. We follow the suggestion of Cooper (2000) and do not synonymize the species. The clade A. cornelliana + A. baezae is supported by the tegula projected anteriorly (char. 57:1).

Cooper (2000) pointed out that A. nebularum is closest to A. cornelliana , A. baezae , and A. xanthopus , which are also montane species with tergum subrectangular behind the spiracles and with ground color black or blackish brown. In figure 6 all the xanthopus group has tergum I subrectangular (= subparallel) (char. 60:1). Although the species is black or blackish brown, Cooper (2000) cited a variant of A. yepocapa from Mexico, which has the anterior half of the mesepisternum paler and a specimen from Jalapa that has only the mesepisternal sulci black. Agelaia nebularum + A. yepocapa and A. fulvofasciata are the only three species in component A, which have bristles on tergum I long and dense (char. 65:0).

THE CLADE ( AGELAIA FULVOFASCIATA + A. HAMILTONI ) + ( FLAVIPENNIS GROUP + BEQUAERTI GROUP)

The homoplastic characters carina on pronotal tubercle on the middle region (char. 34:1); tegula with a hyaline area (char. 58:1) and tergum I slightly concave (char. 63:0) are shared by this clade.