Physotarsus concavus Zhaurova

Zhaurova, Kira & Wharton, Robert, 2009, A revision of Physotarsus Townes (Hymenoptera: Ichneumonidae: Ctenopelmatinae), with description of 18 new species, Zootaxa 2207, pp. 1-52 : 17-19

Physotarsus concavus Zhaurova , n. sp. ( Figs 5 , 20–22 )

Diagnosis. Lateral ocelli separated by 1.1–1.2X their widest diameter from each other and about 1.8-2.0X their widest diameter from eye margin. Antennae with 33–42 flagellomeres. Pronotum completely glabrous. Mesoscutum shiny, very sparsely punctate on anterior 0.3. T1 about twice as long as broad. Head yellow with broad, black median stripe extending from base of antenna through vertex; occiput almost completely black. Mesosoma black and yellow ( Fig. 20 ). T1 yellow basally with two black bands extending from spiracle to or nearly to apex; T2 and often T3 with yellow triangular patch medially, otherwise dark brown to black, remaining tergites largely dark laterally, variously yellow to orange medially. Hind femur and tibia orange, tarsomeres 1 and 2 brown, tarsomeres 3 and 4 usually yellow, sometimes only ventrally. Fore wing entirely hyaline.

Physotarsus concavus is one of several species with a black and yellow mesosoma, a distinctly punctate mesopleuron, and a sparsely to impunctate mesoscutum. It is nearly identical to P. c o rd a t u s, P. emarginatus , and P. truncatus . but differs from these in the possession of distinctly pale middle tarsomeres on the hind leg. The subapical ring on the flagellum is also more distinct in P. concavus .

Physotarsus concavus is very similar in color to P. emarginatus , and to a lesser extent P. c o rd a t u s. The hind tarsi are darker in P. emarginatus and the dorsoposterior corner of the mesopleuron is black, while in P. cordatus the hind legs and metasoma are more extensively orange. Physotarsus concavus differs from both of these species in the more shallowly concave male subgenital plate.

Description. Female: Body ( Fig. 20 ) 4.2–5.9 mm, fore wing 3.8–5.3 mm. Head ( Fig. 21 ): Clypeal margin thick, evenly rounded laterally with thick, rounded central lobe. Clypeus ( Fig. 5 ) about 2.6–2.7X as wide as long, divided medially by very shallow transverse depression. Face covered with very short setae; setae longer, less dense on clypeus. Anterior tentorial pits elongate and upcurved laterally. Malar space 0.4–0.5X width of mandibular base. Face 1.8–1.9X as broad as long, slightly protruding in profile, sparsely punctate laterally, more densely punctate medially. Interantennal area flat, area immediately behind antennae weakly concave laterally turning convex before reaching ocelli. Anterior margin of torulus situated at about 0.7 of eye height. Interantennal distance greater than distance between lateral ocelli. Widest diameter of torulus 1.3X widest diameter of median ocellus. Lateral ocelli separated by 1.1–1.2X their widest diameter from each other and about 1.8–2.0X their widest diameter from eye margin. Area between lateral ocelli slightly depressed, area immediately behind ocelli not sharply declivitous. Antennae with 33–42 flagellomeres, first flagellomere 5.5–6.6X longer than wide, 1.3X widest transverse diameter of eye, second flagellomere 0.6–0.7X length of first. Occipital carina present on ventral 0.6 of head. Mesosoma: Anterior margin of pronotum medially very slightly emarginate, laterally rounded, slightly upcurved. Lateral groove of pronotum well-developed, sculptured, extending over dorsal 0.8, sometimes complete to ventroposterior margin. Pronotum completely glabrous, impunctate. Mesoscutum shiny, very sparsely punctate on anterior 0.3. Epicnemial carina parallels anterior margin of mesopleuron. Mesopleuron punctate, with prominent shiny spot. Metapleuron evenly setose. Propodeum with at least posterior vestige of pleural carina; impunctate medially, moderately densely punctate and pubescent laterally. Tarsal claws with stout setae basally. Fore wing stigma narrow, about 4.0X longer than wide; Rs+2r arising from basal 0.4 of stigma; marginal cell about 3.0X longer than wide; 2rs-m usually 1.6–2.4X longer than abscissa of M between 2rs-m and 2m-cu; Cu1a about 0.5–0.6X length of 2cu-a; cu-a interstitital to antefurcal relative to Rs&M, most commonly distinctly antefurcal. Hind wing M+Cu bowed; basal abscissa of Rs approximately equal length of rs-m; 1st abscissa of Cu1 1.2–1.7X longer than cu- a. Metasoma: T1 about 2.0X as long as broad; with shallow median groove basally fading to flat surface at level of spiracle, moderately convex posteriorly; spiracles not strongly protruding; dorsolateral carina extending 0.5–0.6X distance to spiracle. Cerci distinct, round to slightly ovate, nearly flat.

Male: Subgenital plate not emarginate, its margin even ( Fig. 22 ). Aedeagal margin not toothed. Otherwise similar to female in structure and color except first flagellomere 6.0–7.2X longer than wide, and ratios for quantitative characters in hind wing much more variable.

Color. Head yellow with broad, black median band extending from base of antenna through vertex; occiput almost completely black, black band usually extending anteriorly as narrow stripe to facial tubercle. Antenna usually with 3–4 yellow flagellomeres subapically, occasionally with one or two more, basal and apical members of subapical ring often partly brownish; flagellum otherwise dark brown to black dorsally, brown to light brown ventrally basad subapical ring. Mesosoma black and yellow, with pronotum almost completely black, scutellum yellow, propodeum mostly yellow with black transverse band along anterior margin narrower medially than laterally, mesopleuron largely yellow with broad, black, somewhat diagonal band extending from ventral margin of subalar ridge through mesopleural fovea. T1 yellow basally with two black bands extending from spiracle to or nearly to apex, bands sometimes partially coalescing posteriorly; T2 and often T3 with yellow triangular patch medially, otherwise dark brown to black, remaining tergites largely dark laterally, with varying amounts of yellow to orange medially; cerci light-brown. Fore and mid legs mostly yellow, including coxae, with femora and tibiae sometimes pale orange and apical tarsomeres of mid leg sometimes brown. Hind coxa yellow with broad black band laterally, trochanter and trochantellus largely black, femur and tibia usually extensively orange, tarsomeres 1, 2, and 5 usually dark brown; tarsomeres 3 and 4 usually yellow, sometimes only ventrally. Fore wing entirely hyaline.

Material Examined. Holotype Ψ ( AEIC, Type No. 3849): [ USA, Arizona] first line of data label: “Portal, Ariz.” second line: “IX.3.1974” third line: “H.&M. Townes”. Paratypes: 2 Ψ 1 ɗ, same data as holotype ( AEIC); 19 Ψ 10 ɗ, same data as holotype except dates ranging 13.viii–7.ix.1974, 23.viii1987 & 18.ix.1987 ( AEIC, TAMU); Arizona, 4 Ψ 4 ɗ Parker Canyon Lk., 22–24.viii.1974 (H&M Townes) ( AEIC, TAMU), 1 ɗ Nogales, 22.viii.1974 (H&M Townes) ( AEIC); 1 ɗ MEXICO, Nuevo Leon, San Pedro Iturbide, 32 km W. Linares, 6.x.1962 (H&M Townes) ( AEIC).

Remarks. This species is somewhat color variable, this being perhaps more obvious relative to other species due to the large number of specimens available. The metapleuron, for example, varies from nearly all yellow to all black, and the extent of yellow markings on the mesoscutum is also quite variable. In addition to variation in leg coloration noted in the description, a few specimens from Arizona (not included as paratypes) have the hind tarsi entirely pale. The color variation makes it a challenge to differentiate several similarly colored species from southwestern U. S.

The species name is Latin for concave, referring to the evenly concave margin of the male subgenital plate. This species is known only from southern Arizona and central Nuevo Leon, Mexico, but is likely to occur along the USA / Mexico border between these two areas.

Figures

FIGURES 5 – 8. ESEM, clypeus. 5, Physotarsus concavus n. sp., 6, P. luteus n. sp., 7, P. claviger n. sp., 8, Scolobates auriculatus.

FIGURES 17 – 20. Habitus, face, and male genitalia. 17 – 19, Physotarsus claviger n. sp.; 17, habitus; 18, face; 19, male genitalia, ventral view. 20, P. concavus sp. nov., habitus.

FIGURES 21 – 24. Habitus, face, and male genitalia. 21 – 22, Physotarsus concavus n. sp.; 21, face; 22, male genitalia, ventral view. 23 – 24, P. cordatus n. sp.; 23, habitus; 24, face.