Pseudomethoca peremptrix Williams, 2023

Williams, Kevin A., 2023, Taxonomic updates for diurnal velvet ants (Hymenoptera: Mutillidae) in the United States of America, Zootaxa 5301 (1), pp. 105-123 : 115-117

Pseudomethoca peremptrix Williams , sp. nov.

( Figs 17–23 , 31–34)

Diagnosis. FEMALE. Females of P. peremptrix can be recognized by the following combination of characters: head covered with moderately dense pale-golden setae; head wider than mesosoma, head width between eyes greater than vertex width; mandible acuminate to apex; gena unarmed; hypostoma with small sharp tooth; humeral carina sharp, distinct; T2 disc with two sub-circular pale golden setal spots; pygidial plate moderately narrow, microreticulate. MALE. Males of P. peremptrix can be immediately recognized by the orange-brown body color ( Figs 18, 20 ). The following combination of characters are also useful for diagnosis: body size small (<6 mm); vertex rounded posteriorly; clypeus convex with transverse apical furrow; mandible acuminate to apex; forewing marginal cell longer than stigma length; hypopygium evenly punctate and setose basally, apically bidentate; genitalia with cuspis longer than digitus; penis valve narrow unidentate apically without ventral pre-apical lamella.

Description. FEMALE (holotype). Body length 3.9 mm. Color: Integument pale orange-brown, except frons, vertex, mandibular apex, F3–10, mesonotum, femoral apices, tibiae, T2 postero-dorsally and T6 darker brown ( Figs 17, 19 ). Setae silvery-yellow, except setae blackish-brown on mesonotum and T2 disc (except lateral circular patches of pale golden setae) and T6 setae golden brown. Head: Moderately large, subrectangular; total head width 1.25 × pronotal width, vertex width 1.05 × pronotal width; punctures dense, small; eye large, distance between posterior margins of eye and vertex 0.75 × maximum diameter of eye; genal carina distinct, not reaching hypostomal carina, not reaching posterolateral angle of vertex; hypostomal region with distinct sharp tooth; clypeus anterior margin bidentate, spines small, more widely separated than antennal tubercles; F1 1.4 × pedicel length; F2 1.1 × pedicel length; antennal scrobe carina extending onto antennal tubercle forming short triangular lamella; mandible apically with three equidistant apical teeth, acuminate to apex. Mesosoma: Length (excluding prothoracic collar) subequal to width; mesosoma dorsally areolate-punctate, areolations wider posteriorly; propodeum posterior face mostly smooth with a few shallow reticulations; mesopleuron, metapleuron and lateral propodeal face mostly smooth; humeral carina distinct to epaulet, forming obtuse angle at humeral corner; small spine present immediately anterior to propodeal spiracle; propodeum with dorsal and lateral faces separated by serrate carina. Metasoma. T1 not constricted posteriorly, merging evenly with T2, anterior face with sparse punctures, denser posteriorly; S1 with distinct longitudinal carina; T2 evenly convex throughout, without elevated, longitudinal carinae, densely punctate; T3–5 with fine dense punctures; pygidial plate uniform microreticulae, lateral carinae distinct, width of plate less than half total T6 width ( Fig. 22 ).

MALE. Body length 4.5–5.0 mm. Color. Integument orange-brown, except mandibular apex, antenna, frons, lateral portions of vertex, tegula, femora, tibiae, tarsi and T6–7 darker brown to nearly black; wings translucent, weakly infuscated, veins dark brown; body setae silvery-white, except frons, mesoscutum, mesoscutellum and T3–5 with scattered erect dark brown setae and T6–7 with dense blackish setae ( Figs 18, 20 ). Head. Rounded posteriorly, vertex with sparse coarse punctures; mandible bidentate, acuminate to apex; clypeus punctate, weakly convex, anterior margin edentate, with shallow transverse furrow; antennal scrobe with dorsal carina reduced to transverse tubercle; antennal tubercle smooth; gena ecarinate; ocelli minute, ocellocular distance 5.7 × length of lateral ocellus, interocellar distance 1.9 × lateral ocellar length; scape with one anterior carina; F1 1.8 × pedicel length; F2 2.3 × pedicel length. Mesosoma. Pronotum, mesoscutum and mesoscutellum with scattered coarse punctures; tegula smooth, evenly convex, margins sparsely setigerously punctate; mesopleuron with coarse contiguous punctures; metapleuron and anterior portion of lateral propodeal surface smooth to faint microreticulate, posterior margin of lateral propodeal surface areolate-microreticulate; propodeum areolate dorsally and posteriorly. Forewing stigma small, marginal cell (measured along costa) 1.9 × stigma length. Metasoma. T1 shape sessile; S1 with irregular longitudinal carina; T2 with separated punctures, intervals smooth; S2 sculpture coarser than T2; T3–6 fringe setae variable in length, apparently simple; T3–6 punctures sparse; T7 anterior third punctate and setose, with laterally defined rugose pygidial plate, apical margin with short dense setae; hypopygium basally with uniform punctures and setae, smooth and sharp bidentate posteriorly. Genitalia ( Figs 31–34 ). Paramere weakly dorsoventrally flattened, weakly sigmoidal externo-ventrally, with moderately short latero-ventral setae. Cuspis sub-triangular with dense long setae interno-ventrally.Digitus shorter than cuspis. Penis valve unidentate apically without transparent preapical ventral lamella.

Material examined. Holotype, female, USA, Arizona, Santa Cruz Co., Duquesne Road at western edge of National Forest , 31.374 –110.821, 29.VII–4.IX.2017, pitfall trap, W. B. Warner ( CSCA) . Other material. USA, Arizona, Same data as Holotype (2 males, CSCA) ; MEXICO, Sonora, 30 mi. S Guaymas , 4.IX.1970, R. M. Bohart (2 males, UCDC) .

Distribution. Mexico (Sonora) and USA (Arizona).

Etymology. From the Latin peremptrix “she that destroys or kills”. The name is based on the similarity of this new species to Pseudomethoca perditrix Krombein, 1992 , which was named using a Latin term for destroyer.

Remarks. In color, body shape, size and distribution, this new species is superficially similar to P. perditrix , differing from that species by the presence of silvery setal spots on T2 (uniform setae in P. perditrix ), the dentate hypostomal carina (unarmed in P. perditrix ) and the slender pygidial plate (broader in P. perditrix ). In the most recent key to North American Pseudomethoca species ( Mickel, 1935), the female keys out to P. dentigula Mickel, 1935 from Texas. Unlike that species, the head has pale golden setae (head setae blackish in P. dentigula ) and the head shape is smaller and more rounded in P. peremptrix (large and quadrate in P. dentigula ). In Mickel’s (1935) key, the male keys out to P. gila ( Blake, 1871) . The male of P. peremptrix , however, can be immediately recognized by the orange-brown body color.

There is a small chance that this male might actually be P. perditrix , so males are not designated as paratypes. Two females of P. perditrix and the holotype female of P. peremptrix were collected using pitfall traps at the type locality by W.B. Warner. The two orange-brown males were found in the same collecting event as the holotype female (29.VIII–4.IX.2017), but the females of P. perditrix were collected on different dates (4–30.IX.2017 and 14– 31.VIII.2018). Male velvet ants are not common in pitfall traps and co-occurrence of males and females in the same pitfall trap has been used to support sex associations in other species ( Manley & Radke, 2002). Also, P. perditrix is relatively widespread in Arizona and has been seen as far North as Nevada, but, in the USA, no small-bodied orange-brown Pseudomethoca males have been seen outside this type locality. For these reasons, these orange males are almost certainly males of P. peremptrix .

Figures

FIGURES 17–23. Pseudomethoca peremptrix, sp. nov. 17, 19, 21, 22. Female. 18, 20, 23. Male. 17–18. Dorsal habitus. 19–20. Lateral habitus. 21, 23. Head, anterior view. 22. Pygidium.

FIGURES 31–38. Pseudomethoca species, male genitalia: dorsal view, ventral view, sagittal view, penis valve lateral view. 31–34. P. peremptrix, sp. nov. 35–38. P. sonorae, sp. nov.