Pseudostrangalia cruentata mcivori, Heffern & Santos-Silva, 2025

Heffern, Daniel & Santos-Silva, Antonio, 2025, Description of a new subspecies of Pseudostrangalia cruentata (Haldeman, 1847) (Coleoptera, Cerambycidae, Lepturinae) from the United States of America, Zootaxa 5569 (2), pp. 383-392 : 384-391

Pseudostrangalia cruentata mcivori ssp. nov.

( Figs 1–8, 10–11 )

Description. Holotype male ( Figs 1–4 , 8, 10 ). Head capsule black except reddish-brown central area between upper eye lobes, dark reddish-brown sides and dark-brown central area of frontal plate, and brown central area and anterior margin of intermaxillary process; wide central area of clypeus dark brown, slightly lighter laterally close to frons, except yellowish-brown apex close to genae and pale-yellow sides close to labrum; labrum blackish on posterior third, mostly yellowish brown on anterior 2/3; ventral mouthparts both dark brown and yellowish brown, except blackish palpomeres with yellowish-brown apex on maxillary palpomere IV; scape, pedicel, and antennomeres III–IV shiny black; antennomeres V–XI dull dark brown. Prothorax blackish. Ventral surface of mesothorax mostly dark brown. Mesanepisterna dark orangish brown with irregular brown areas, except brown inner margin. Metaventrite dark orangish brown laterally, orangish on remaining surface. Scutellum dark orangish brown, slightly lighter toward apex. Elytra black. Procoxae mostly dark brown; mesocoxae dark brown; metacoxae mostly dark reddish brown on outer side, gradually lighter toward inner side, except dark-brown posterior area close to trochanter. Pro- and mesotrochanters dark brown except dark yellowish-brown base; metatrochanters yellowish brown on basal half, dark brown on apical half. Profemora blackish except reddish-brown ventral surface on basal third; mesofemora orangish brown on basal half, blackish on apical half; metafemora orangish brown on basal 3/4, blackish on apical quarter. Tibiae and tarsi black, except dark yellowish-brown tarsal claws. Abdominal ventrites 1–4 dark orangish brown with irregular brown areas interspersed, except both pale-yellow and orangish brown apex of ventrite 4; ventrite 5 orangish brown.

Head. Frons abundantly, coarsely punctate, except subsmooth, triangular frontal plate, which may appear less triangular depending on viewing angle; with sparse, moderately short, erect yellowish setae centrally, except almost glabrous frontal plate, and moderately sparse, erect dark-brown setae laterally. Area between antennal tubercles and inferior margin of upper eye lobes moderately abundant, coarsely punctate, except dense, confluent punctures close to posterior half of eyes; remaining surface of vertex depressed, moderately finely and sparsely punctate, except smooth central area; with sparse, moderately long, erect yellowish setae, setae more abundant and longer laterally close to depressed region. Area behind eyes tumid close to eye; with moderately sparse, erect dark brown setae on tumid area, setae both as long or long than on vertex, glabrous close to prothorax. Antennal tubercles sparsely, finely punctate; with sparse, long, erect yellowish setae on inner surface and long dark-brown setae toward apex. Genae moderately abundantly, coarsely punctate, punctures slightly sparser toward frons and clypeus, except smooth frontal apex and area close to clypeus and frons; with moderately abundant, bristly yellowish-white setae not obscuring integument, setae absent on smooth areas. Postclypeus moderately abundantly, coarsely punctate, except smooth anterocentral area; with sparse, long, erect yellowish-white setae except more abundant yellowish-brown setae laterally close to labrum. Labrum shallowly, coarsely punctate on dark integumental area, subsmooth on remaining surface; with moderately sparse, long, erect yellowish-brown setae, except brown setae anterocentrally and fringe of short yellowish-brown setae on anterior margin. Gulamentum smooth, glabrous on posterior half; anterior half moderately abundantly, shallowly, coarsely punctate, with sparse, long, erect yellowish-white setae laterally, setae almost absent centrally, except intermaxillary process almost smooth, with a few short, bristly yellowish-white setae. Basal 3/4 of outer side of mandibles abundantly, coarsely punctate, with moderately abundant, long, erect yellowish-brown setae not obscuring integument; apical quarter smooth, glabrous. Distance between upper eye lobes 0.49 times distance between outer margins of eyes; in frontal view, distance between lower eye lobes 0.64 times distance between outer margins of eyes. Antennae 1.6 times elytral length, reaching elytral apex at middle of antennomere XI. Scape abundantly, moderately coarsely punctate, except ventral surface partially smooth on apical half; with moderately abundant, both short and long, erect dark brown setae not obscuring integument, except glabrous smooth area. Pedicel and antennomeres III–IV abundantly, moderately coarsely punctate, except smooth apex on III–IV; with abundant, bristly, short dark-brown setae not obscuring integument, setae denser, partially thick ventrally. Antennomeres VI–XI densely, very finely punctate; with abundant, bristly yellowish-white pubescence not obscuring integument. Antennal formula based on length of antennomere III: scape = 1.28; pedicel = 0.36; IV = 0.96; V = 1.44; VI = 1.68; VII = 1.60; VIII = 1.52; IX = 1.44; X = 1.36; XI = 1.64.

Thorax. Prothorax subtrapezoid; anterior margin straight; posterior margin slightly sinuous; sides divergent from anterolateral to posterolateral angles, concave from middle to posterior angle; anterior and posterior constrictions narrow, well marked; posterolateral angles with blunt apex. Pronotum slightly gibbous on each side of anterior third, moderately depressed posterocentrally; moderately abundantly and coarsely punctate, punctures slightly coarser on posterior third and appears to be finer depending on viewing angle; with moderately abundant, long, erect, both dark-brown and yellowish setae, part of setae dark brown basally, yellowish toward apex; setae on posterolateral angles abundant, long, dark brown. Sides of prothorax moderately abundant, finely punctate superiorly, abundant, partially confluent, shallowly, coarsely punctate inferiorly; with moderately abundant, long, erect setae throughout, except close to anterior margin, setae mostly dark brown. Prosternum abundantly, coarsely, somewhat rugose-punctate on posterior 3/4, except smooth area close to procoxal cavities, sparsely, finely, shallowly punctate on anterior quarter; with sparse, erect whitish setae on posterior 3/4, except glabrous smooth area, almost glabrous on anterior quarter, except sides with long, erect dark-brown setae. Prosternal process strongly narrowed on central area, triangularly expanded apically; with sparse, bristly whitish setae; narrowest area 0.08 times procoxal width. Ventral surface of mesothorax abundantly, coarsely, somewhat rugose-punctate; with sparse yellowish-white pubescence on central area of mesoventrite and abundant, bristly yellowish-white pubescence not obscuring integument on remaining surface. Mesoventral process slightly narrowed from base to apex, strongly notched apically; narrowest area 0.45 times mesocoxal width. Metanepisterna and sides of metaventrite with abundant whitish pubescence not obscuring integument; remaining surface of metaventrite with whitish pubescence gradually sparser toward central area. Scutellum with sparse, both brown and yellowish pubescence anteriorly, pubescence gradually denser toward apex. Elytra. Abundantly, coarsely punctate; with abundant, erect dark-brown setae throughout, some setae yellowish apically; posterior quarter of epipleural and apical margin with moderately long, thick dark-brown setae.

Legs. Coxae with moderately abundant, both whitish and yellowish pubescence not obscuring integument. Pro- and mesotrochanters with abundant, both whitish and yellowish pubescence not obscuring integument; metatrochanters with fringe of moderately abundant yellow setae on posterior half. Profemora with moderately abundant, bristly dark-brown setae not obscuring integument, except sparse setae on inner surface and yellowish setae gradually sparser toward apex on ventral surface; meso- and metafemora with abundant, bristly yellow setae on light integumental area, denser ventrally, and moderately abundant dark-brown setae on remaining surface. Protibiae with abundant, short, erect yellowish setae dorsally and laterally, setae distinctly denser on apical half of inner surface, and abundant, short, erect dark-brown setae ventrally; meso- and metatibiae with abundant, short, erect dark-brown setae. Dorsal surface of tarsi with moderately abundant, bristly dark-brown setae not obscuring integument; metatarsomere I 1.8 times longer than II–III together.

Abdomen. Ventrites with sparse, short, bristly yellowish setae not obscuring integument, except glabrous apex of ventrites 1–4; apex of ventrite 5 rounded, slightly emarginate centrally.

Female ( Figs 5–7 , 11 ). Similar to male, differing by: most of head and entire prothorax orangish; scutellum often mostly orangish; antennae shorter, 1.3 times elytral length, almost reaching posterior tenth of elytra (only one female measured); and apex of abdominal ventrite 5 rounded, with slightly rounded projection centrally.

Variation, male paratypes. Head capsule and clypeus entirely black; posterolateral angles of prothorax wide, distinctly rounded.

Dimensions (mm) (holotype male/male paratype /females paratypes). Total length, 8.95/9.40/8.55–14.25; prothoracic length, 1.55/1.65/1.40–1.95; anterior prothoracic width, 1.10/1.00/1.00–1.30; posterior and maximum prothoracic width, 2.20/2.25/1.90–3.25; humeral width, 2.60/2.70/2.55–4.20; elytral length, 4.75/5.50/5.35–7.80. Note: only five specimens were measured, one paratype male and three females.

Type specimens. Holotype male from the UNITED STATES OF AMERICA , Texas: Jeff Davis Co., Davis Mts Preserve , Madera Canyon , 1940 m, 30.657°N 104.166°W, hanging jug trap, ethanol/red wine bait, IV.22/ VI-4-2022, B. Raber & D. Heffern leg. ( TAMU) . Paratypes – UNITED STATES OF AMERICA , Texas: same data as holotype, 1 male, 1 female ( MZSP) ; same data as holotype, 1 male ( DHCO) ; 2 males, 1 female, same data as holotype except 1945 m, 30.657°N 104.168°W, IV.21 /VI.10.2023, D. Heffern, E. Riley & B. Raber leg. ( DHCO); 4 females, same data as holotype, except 2036 m, below Tobe Spring , 30.648°N 104.178°W, IV.25 /V.25.2024, D. Heffern, E. Riley & B. Raber leg. ( BRCO, DHCO, ERCO, SLCO); 1 male, 1 female, same data as holotype, except 2050 m, below Tobe Spring , 30.647°N 104.179°W, IV.25 /V.25.2024, D. Heffern, E. Riley & B. Raber leg. ( DHCO); 1 female, same data as holotype, except 2070 m, below Tobe Spring , 30.646°N 104.179°W, adult cut out of Quercus hypoleucoides A. Camus , 26.IV.2024, J. Vlasak leg. ( JVCO) .

Etymology. The new subspecies is dedicated to the late Don McIvor, who sold his ranch on Mount Livermore to The Nature Conservancy, which preserves the habitat of the taxon.

Biology. One adult (female paratype, JVCO) was extracted from a pupal cell within dead wood of living Quercus hypoleucoides A. Camus, 1932 ( Fagaceae ). The adult was nearly completely hardened and may have emerged within a week or two. The tree diameter was approximately 12cm with a scar of hard and dry wood on the outside but with moist wood deep inside close to the living tissue ( Fig. 21 ). The moist part was riddled with galleries and this is where pupation also took place (Josef Vlasak, pers. comm.). Immature lepturine larvae were found by Ronald Alten and the first author in the same vicinity, also in Q. hypoleucoides , on 25-V-2024. The first author believes this supports the idea that more than one year may be required to complete development.

Remarks. Although the new subspecies differs from the nominotypical subspecies only in the color pattern, these differences are constant. No specimens of P. c. cruentata Swaine & Hopping, 1928 are known with intermediate colors between them and the specimens of P. c. mcivori. This is true for specimens of P. c. cruentata examined in person and for those studied through photographs, descriptions, and redescriptions. Although we are unaware of this type of difference in Lepturinae , similar cases have already been reported for insects, for example, Sphecophaga vesparum vesparum (Curtis, 1828) and S. v. burra (Cresson, 1869) ( Hymenoptera , Ichneumonidae ). According to Berry et al. (1997) on the subspecies of S. vesparum : “We examined 164 specimens of S. v. vesparum and 87 specimens of S. v. burra , and scored 13 characters. Results showed that the two subspecies could not be reliably discriminated on any morphological characters, but that three colour characters gave>98% separation for females (not including the character originally used to define the subspecies), and seven colour characters gave 100% separation for males;” and “ Sphecophaga v. burra and S. v. vesparum could not be distinguished by any morphological features. However, we found that females of the two subspecies could be reliably discriminated (little overlap between character states) on four colour characters; the character that Townes & Townes (1962) used—colour of hind coxae and trochanters—was the least reliable of the four. Males could be discriminated on seven colour characters, although sample sizes were smaller and so the results are less reliable.”

Pseudostrangalia cruentata mcivori ssp. nov. differs from P. c. cruentata (Haldeman, 1847) ( Figs 9, 12–19 ) as follows: elytra entirely black in both sexes; prothorax always orange in females; prothorax always black in males and mesofemora bicolorous in both sexes ( Figs 2, 7 ). In P. c. cruentata , the elytra have a large, usually longitudinal, reddish or orangish area laterally, prothorax is black in females, and the mesofemora are entirely dark ( Figs 15, 19 ).

Quercus hypoleucoides A. Camus , is only found in Texas ( USA) in the Davis Mountains . The type locality of the new subspecies is in a mesic forest, which receives most rainfall from June through September (summer monsoons). Quercus hypoleucoides grows mainly in canyons or scattered in pine forests ( Vines 1960). Substantial numbers of this oak occur in Madera Canyon on the north slope of Mt. Livermore where the type series was collected. The first author has also seen this oak on other sides of Mt. Livermore such as Goat Canyon on the south side and Limpia Canyon on the east side.

In the eastern half of Texas, the nominate subspecies is an early spring species found from early March until the middle of April and usually taken on blooms of Crataegus sp. ( Rosaceae ) or Cornus drummondii C. A. Meyers ( Cornaceae ). The new subspecies, likewise, was also found relatively early (late April and May, considering the cooler temperatures at higher elevations), however there are extremely few bushes or trees with flowers at this time. This is probably why the ethanol / red wine bait was effective.

Pseudostrangalia cruentata mcivori appears to have avoided scientific discovery for the simple reason that higher areas (> 1900m) of the Davis Mountains are privately owned with restricted or no access. Additionally, it occurs in late spring before the summer monsoons and traditional fieldwork occurs. The first author has set bait traps at lower elevations in the Davis Mountains Preserve (below 1900 m) dominated by gray oaks ( Quercus grisea Liebm. ) and has not collected any specimens of the new subspecies in those locations.

Pseudostrangalia c. cruentata occurs over a wide area of Eastern North America , from central Texas to Iowa, Michigan, New York, North Carolina ( USA), and southern Quebec ( Canada) (see maps in Chemsak (2005) and Bousquet et al. (2017)). An updated map for only Texas is provided here ( Fig. 22 ). The distance between the type locality of the new subspecies and the westernmost record for the nominate subspecies is approximately 460 km (285 mi).

Figures

FIGURES 1–7. Pseudostrangalia cruentata mcivori ssp. nov. 1–4) Holotype male: 1) Dorsal habitus; 2) Ventral habitus; 3) Lateral habitus; 4) Head, frontal view. 5–7) Paratype female: 5) Head, frontal view; 6) Dorsal habitus; 7) Ventral habitus.

FIGURES 8–13. Pseudostrangalia sspp. 8) P. cruentata mcivori ssp. nov., holotype male, head, dorsal view; 9) P. cruentata cruentata (Haldeman, 1847), male, head, dorsal view; 10–11) P. cruentata mcivori, anterior region of the elytra: 10) Holotype male; 11) Paratype female. 12–13) P. cruentata cruentata, anterior region of the elytra: 12) Male; 13) Female.

FIGURES 20–22. 20) Typical trap used to collect specimens of P. c. mcivori. 21) Quercus hylopeucoides A. Camus, specimen from which an adult of P. c. mcivori was extracted. 22) Map of Texas (USA) showing the geographic distribution of P. c. cruentata (red circles) and P. c. mcivori (green circle).

FIGURES 14–19. Pseudostrangalia cruentata cruentata (Haldeman, 1847). 14–16) Male: 14) Dorsal habitus; 15) Ventral habitus; 16) Head, frontal view. 17–19) Female: 17) Head, frontal view; 18) Dorsal habitus; 19) Ventral habitus.