Ptilothrix zacateca, Flórez-Gómez & Danforth, 2023

Florez-Gomez, Nathalia & Danforth, Bryan, 2023, The North American bees of the genus Ptilothrix Cresson, 1878 (Hymenoptera, Apidae, Emphorini), with the description of two new species, Journal of Hymenoptera Research 95, pp. 275-293 : 275

Ptilothrix zacateca sp. nov.

Figs 2C, D , 3C, D , 4C , 5 , 6

Diagnosis.

Female body size from 11.3-12.7 mm, male 10.5-13 mm. This species can be recognized by the overall whitish to pale yellowish pubescence, except for that on the female basitarsi, which is dark yellowish to pale brown. Differing from P. sumichrasti and P. chiricahua by the longer first flagellomere (length at least twice its apical width), presence of erect, overall longer pubescence, especially on the anterior areas of T2 and T3, more robust body and slightly larger size. Both sexes with tergal hair bands on T1-T4 in females, T1-T6 in males.

Description.

Male. Total length 12.34 mm (paratypes 10.5-13 mm, n=7). Head. Integument black, except brown middle area of the mandible, mandibular apex yellowish in some paratypes. Uniformly whitish pubescence covering all of the head except ocellocular area where hairs are sparser. Mandible with rounded apical margin. Maxillary palpus 6-segmented. Labrum rectangular, disc densely punctate, margin raised and impunctate. Clypeus slightly protuberant in lateral view, with coarse punctation. Inner ocular margins subparallel. Frons, paraocular area and vertex with close punctures, separated by a distance up to a puncture diameter. Ocellocular integument micro-sculptured and with punctures towards the eye margin, small area around the lateral ocellus polished and shiny, distance 0.63 mm. Antennae black, scape 0.8 mm, first flagellomere 2.5 times longer than its apical width. Head length 3.25 mm. Head width 3.85 mm. Gena width 0.8 mm. Lower interocular distance 2.45 mm. Upper interocular distance 2.5 mm. Interocular distance 1.03 mm. Antennocular distance 0.41 mm. MOD 0.25 mm

Mesosoma. Integument black. Overall pubescence whitish on pronotum, scutum, scutellum, mesepisternum, metepisternum and propodeum; pale yellowish on the scutum of some specimens. Scutum with close punctures regularly distributed, separated by less than a puncture diameter with shiny interspaces. Scutellar punctures even more closely spaced than those of the scutum. Disc of mesepisternum punctured as in scutum, deep punctures and very close one to each other, imbricate interspaces between punctures. Hypoepimeral area deeply and densely punctate, micro-sculptured towards the scrobal groove. Propodeal triangle with whitish short pubescence, middle line glabrous. Tegulae translucent brown. White tuft of hairs at the base of wings, membrane of wings slightly infuscate, venation brownish. Length of forewing 10.83 mm. Intertegular distance 3.25 mm. Scutum length 3.0 mm. Legs. Integument black to dark brown, except tarsi reddish brown. Pubescence whitish overall. Hind coxa and femur enlarged. Hind basitarsus slightly curved, 6 times the length of the second tarsomere. Hind tibial spurs dark brown, slightly hooked at the apex.

Metasoma. Overall integument black, margin of sterna subhyaline. T1-T4 with dense, whitish erect pubescence, posterior margin with band of white hairs. T5-T6 with dense and erect black pubescence on the anterior area, margin with a band of whitish dense pubescence. T7 covered with black pubescence, margin with two pointed projections forming a middle notch. Sterna with dense, whitish, erect pubescence. S6 with a median tuft of hairs. S7 and S8 as in Fig. 2C, D . Gonobase rounded, gonostylus filiform (Fig. 3C, D ).

Female. Total length 12.67 mm (11.3-12.7 mm n=8). Head. Integument color as in male, pubescence as in male, but less abundant. Mandible color and shape as in males. Labrum densely punctate, with subtriangular, raised, impunctate apex. Clypeus with coarse punctures separated by a distance up to twice a puncture diameter. Punctation of paraocular area and frons as in males, puncture size smaller than those on clypeus. Inner ocular margins nearly parallel. Integument of ocellocular area as in males, distance 0.76 mm. Antennae black, scape 0.93 mm long, first flagellomere 2.3 times longer than its apical width (Fig. 4C ). Head length 3.48 mm. Head width 4.49 mm. Gena width 0.83 mm. Lower interocular distance 2.81 mm. Upper interocular distance 2.85 mm. Interocular distance 1.22 mm. Antennocular distance 0.47 mm. MOD 0.30 mm. Mesosoma. Color, punctures and pubescence as in males, but pubescence shorter. Wing color and tegula as in male. Wings and tegula as in males. Length of forewing 10.62 mm. Intertegular distance 3.75 mm. Scutum length 3.37 mm. Legs. Overall black integument except brown tarsi. Hind tibia with whitish scopa, apical margin with a tuft of white pubescence, inner surface rugose and with short, whitish and appressed hairs. Scopa on hind basitarsus entirely dark yellowish to pale brown. Metasoma. Integument as in male. T1- T2 with erect whitish hairs, posterior margin with bands of whitish pubescence. T3 and T4 with whitish erect pubescence on the anterior area shorter than those in T1-T2, and with bands of pubescence. Prepygidial fimbria brownish, with whitish hairs intercalated laterally. Pygidial plate with rounded apex. Sterna with erect long, whitish-yellowish pubescence on the disc, denser at the margins.

Material examined.

Holotype. Mexico • ♂; Zacatecas; Guadalupe ; 28 Jun. 1953; C. & P. Vaurie leg.; D. Rockefeller Mex exped.;> AMNH

Paratypes. Mexico - Durango • 2 ♂; 14 mi N.E of Durango ; alt. 1889 m; 17 Jun. 1956; H.A. Scullen leg.; BBSL - Jalisco • 1 ♀; Villa Guadalupe; 26 Jul. 1951; H. E. Evans leg.; SEM SM0803860 • 1 ♂; same data as for preceding; SEM SM0803859 - Zacatecas • 3 ♂; same data as for holotype • 6 ♀; Fresnillo ; alt. 2133 m; 15 Aug. 1947; C.D. Michener leg.; D. Rockefeller Mex exped.;> AMNH. - Hidalgo • 1 ♀; 3 mi Pachuca; Kansas University Mexico exped.; 24 Jun. 1953; on Argemone ; UCRC 546145 • 1 ♂; same data as for preceding; UCRC 546145 .

Comments.

This species is endemic to Mexico. Records are from the mountain regions in the Sierra Madre Occidental from 1800-2000 m (Fig. 5 ). Its preferred host plants are unknown, although two specimens were collected on Argemone flowers, suggesting a possible association. But labels of most of observed material did not include information about related plants and specimens did not have pollen loads to facilitate these associations. It has been collected from June-August.

Etymology.

This species is named in honor to the Zacatecos, the indigenous group that inhabited the state of Zacatecas, the area where the holotype was collected.

Figures

Figure 2. A Ptilothrix chiricahua sp. nov. male S 7 B Ptilothrix chiricahua sp. nov. male S 8 C Ptilothrix zacateca sp. nov. male S 7 D Ptilothrix zacateca sp. nov. male S 8 E Ptilothrix sumichrasti male S 7 F Ptilothrix sumichrasti male S 8 G Ptilothrix bombiformis male S 7 H Ptilothrix bombiformis male S 8.

Figure 3. A, B Ptilothrix chiricahua sp. nov. male genital capsule A dorsal view B ventral view C, D Ptilothrix zacateca sp. nov. male genital capsule C dorsal view D ventral view E, F Ptilothrix sumichrasti male genital capsule E dorsal view F ventral view G, H Ptilothrix bombiformis male genital capsule G dorsa view F ventral view.

Figure 4. Ocellocular area and antenna of A female lectotype of Ptilothrix sumichrasti B female paratype of Ptilothrix chiricahua sp. nov. C female paratype of Ptilothrix zacateca sp. nov.

Figure 5. Distribution map of the North American species of the genus Ptilothrix: Ptilothrix chiricahua sp. nov., Ptilothrix zacateca sp. nov., Ptilothrix sumichrasti and Ptilothrix bombiformis.

Figure 6. Ptilothrix zacateca sp. nov. A male holotype habitus, lateral view B male holotype habitus; frontal view C male holotype dorsal view D male holotype metasoma E female paratype habitus, lateral view F female paratype habitus, frontal view G female paratype dorsal view H female paratype metasoma.