JHR 85: 57-79 (202 1) yaa JOURNAL OF 4 Preewed openscess our doi 10.3897/hr.85.67792 RESEARCH ARTICLE () Hymenoptera The International Society of Hymenopterists RESEARCH https://jhr.pensoft.net Revision of Nearctic Heterischnus Wesmael, 1859 (Hymenoptera, Ichneumonidae, Ichneumoninae, Phaeogenini) Brandon Claridge! | Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT, 84322, USA Corresponding author: Brandon Claridge (brandonclaridge1 @gmail.com) Academic editor: Gavin Broad | Received 29 April 2021 | Accepted 6 June 2021 | Published 31 August 2021 http://z00 bank. org/17378F99-93CF-4C53-8513-9879AIBCA2DE Citation: Claridge B (2021) Revision of Nearctic Heterischnus Wesmael, 1859 (Hymenoptera, Ichneumonidae, Ichneumoninae, Phaeogenini). Journal of Hymenoptera Research 85: 57—79. https://doi.org/10.3897/jhr.85.67792 Abstract The Nearctic species of Heterischnus Wesmael are revised. Redescriptions are provided of the three known species, H. bicolorator, H. huardi and H. coloradensis. Heterischnus mexicanus sp. nov. is newly described and H. bicolorator is recorded for the first time from the Nearctic region. The first key to the Nearctic spe- cies is provided along with species images and distribution maps. Keywords Ichneumoninae, Phaeogenini, new species, taxonomy Introduction Heterischnus Wesmael (Hymenoptera: Ichneumonidae: Ichneumoninae) is a morpho- logically well-defined genus in the tribe Phaeogenini and is comprised of 30 described species in the Holarctic and Afrotropical regions (Yu et al. 2016). Heterischnus was formerly placed in the subtribe Heterischina (Diller 1981; Selfa and Diller 1994). However, Santos et al. (2021) found that the majority of the Phaeogenini subtribes were non-monophyletic and are therefore not recognized here. Heterischnus species are parasitoids of microlepidoptera, especially Pterophoridae (Bragg 1970; Sedivy 1986; Diller and Shaw 2014). Rearing records from other groups, such as noctuids (Rudow Copyright Brandon Claridge. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. 58 Brandon Claridge / Journal of Hymenoptera Research 85: 57-79 (2021) 1917; Meyer 1934) or even bark beetles (Scolytinae) (Uchida 1956), are suspect. Fe- males of at least some species overwinter as adults (Diller and Shaw 2014; Longu-Con- stantineanu and Constantineanu 2014), and as in nearly all ichneumonines, adults emerge from the host pupa (Diller and Shaw 2014). Species richness for Heterischnus is concentrated in the Palearctic with only five described species known from the Afrotropical region and three from the Nearctic (Yu et al. 2016). Unlike the Palearctic and Afrotropical regions, which have been the subject of more recent taxonomic works (Perkins 1959; Aubert 1965; Diller 1995; Selfa and Diller 1997; Rousse et al. 2013; Valemberg 2014), research on the Nearctic Heterischnus ended in the early twentieth century (Cushman 1927). The purpose of the current paper is to revise the Nearctic species. One new species is described and Heterischnus bicolorator (Aubert) is newly recorded from the Nearctic region. A species key is provided, along with images and distribution maps to aid in identification. Materials and methods Morphological terminology follows Bennett et al. (2019). “MS1” refers to the first metasomal segment and “T2”, “T3”, ect. refer to the corresponding metasomal ter- gites. Females are described in full, while only deviations in structure and color are noted for males. Specimen images were taken with a Canon EF-S 60mm macro lens for habitus images and a Venus Optics Laowa 25mm Ultra-Macro lens for higher magnification images mounted on a Canon 1200D camera body. Image stacking was performed with Helicon Focus and further processed in the web-based photo editor Photopea (photopea.com). Figures were assembled in LibreOffice Draw 5.4.4.2. Dis- tribution maps were generated in the open-source software QGIS 3.6.2. Specimens examined are deposited in the following collections: CNCI Canadian National Collection of Insects, Arachnids and Nematodes Agricul- ture Canada: Ottawa, Ontario, Canada; EMUS_ Entomology Museum, Utah State University: Logan, Utah, USA; UCDC Bohart Museum of Entomology: University of California, Davis: Davis, Cali- fornia, USA; USNM_ National Museum of Natural History, Smithsonian Institution: Washington D.C., USA; Results Heterischnus Wesmael, 1859 Heterischnus Wesmael, 1859: 83. Type species: Ichneumon pulex Miller. Monotypic. Rhexidermus Forster, 1869: 192. Type species: Rhexidermus japonicus Ashmead. Mono- typy by inclusion in Ashmead (1906). Revision of Nearctic Heterischnus (Hymenoptera, Ichneumonidae, Ichneumoninae) 59 Posocentrus Provancher, 1875: 273. Type species: Posocentrus huardi Provancher. Monotypic. Ischnopsidea Viereck, 1914: 77. Type species: Ichneumon thoracicus Gravenhorst. Monotypic and original designation. Aethiopischnus Heinrich, 1938: 127. Type species: Aethiopischnus olsoufieffi Heinrich. Monotypic and original designation. Generic diagnosis. Among Phaeogenini genera, Heterischnus is easily recognized by a combination of the following: unidentate, falciform mandible; epistomal suture dis- tinct; basal flagellomeres slender and elongate (Fig. 1); scutellum moderately narrow, convex, and distinctly elevated above metanotum; areolet (cell 1-2Rs) of the fore wing is closed (Fig. 1); hind coxa simple; thyridium wide. In some species, notably He- terischnus huardi (Provancher), the clypeus is medially truncate with acute sublateral projections making such species instantly recognizable as Heterischnus. However, the ventral clypeal margin varies between the aforementioned morphology and being me- dially straight without acute sublateral projections. The majority of species tend toward the latter condition. Additionally, the tarsal claws of Heterischnus pulex (Miiller) are pectinate which is unique among Phaeogenini, although the tarsal claws are simple in the remaining species. Key to the Nearctic species of Heterischnus 1 Coxae black (Fig. 2A). No trace of white markings on head or mesosoma (Fig. 2A—C). Gena rugulose-punctate, sculpture becoming denser ven- GA PE ae en erage Ta beg Sane fe urea ge anes ee ac ae ue Reece H. bicolorator — Coxae light brownish-red or yellowish-white (e.g. Fig. 7A). Yellowish-white markings on mesosoma or head (e.g. Figs 7A, 8B). Gena punctate without EUS OSIOV. wcedha consi bacvnnd vcs wteAiis ewes Linsey sVaneidsUdeunte deapione lu aodgsaVasunes ihe sebsewen lUiacvdetener im 2 Propodeum densely and coarsely punctate (Fig. 10E). Propodeum with lon- gitudinal carinae reduced or obsolete and at least lateral longitudinal carina obsolete posteriorly (Fig. 10E). Female with flagellomeres 7-8 to 11-12 waitedorsally-(BiG VO): esisiies sioulelsatotiea taeabanlttatisn senate H. mexicanus sp. nov. = Propodeum smooth (Fig. 7E) or rugulose-punctate (Fig. 4E). Propodeal longi- tudinal carinae well-developed (Figs 4E, 7E). Female with flagellomeres 10-12 dorsally white (Fig. 4A) or antennae entirely dark-brown (Fig. 7A)..........0. 3 3 Supra-antennal area densely rugulose-punctate (Fig. 4D). Supraclypeal area densely rugulose-punctate (Fig. 4C). Females with flagellomeres 10-12 dor- sally white. Male clypeus black or dark reddish-brown (Fig. 5B)... eee Be rer an rope enn pe Ry Me IRAN arr Ban er AE Aa oP H. coloradensis - Supra-antennal area smooth with fine and sparse punctation (Fig. 7D). Su- praclypeal area punctate or moderately rugulose-punctate (Fig. 7C). Females with no trace of white markings on flagellomeres (Fig. 7A). Male clypeus pri- marily white with ventral margin black to dark reddish brown (Fig. 8B)........ Frode Moraasbart onal ce mula dvalicdarme st mene teaser dmedistnarestesaltiectornes H. huardi 60 Brandon Claridge / Journal of Hymenoptera Research 85: 57-79 (2021) Asc Teme A Figure |. Unpublished illustration of Heterischnus huardi (Provancher) lateral habitus and frontal view of head by Professor Masaaki Tokunaga or his assistants, commissioned by Dr. Henry Townes. Heterischnus bicolorator (Aubert) Figs 2, 3 Rhexidermis bicolorator Aubert, 1965: 16. Syntype series of 14 specimens [Musée de Zo- ologie, Lausanne, Switzerland]. Images of syntype (GBIFCH00759357) examined. Diagnosis. Heterischnus bicolorator can be distinguished from other Nearctic Heterisch- nus species by a combination of the following: 1) flagellum, clypeus, and mesosoma without white markings; 2) coxae black to dark brown; 3) gena rugulose-punctate; and 4) T2—3 brownish-red. Description. Female (Fig. 2). Body length: 7.7—8.2 mm. Fore wing length: 5.0— 5.4 mm. Color. Head black, except brownish-red mandibular apex. Antenna brown. Meso- soma black. Legs brownish-red with coxae and trochanters varying from black to dark brown, except for brown tarsomere 5. MS1 varying from 0.5 anterior black to dark brown with 0.5 posterior brownish-red, to entirely black; T2 varying from entirely brownish-red, to brownish-red with 0.1 posterior brown; T3 brownish-red with posterior 0.1 brown to dark brown; T4—7 dark brown to black. Wing membrane clear; veins light brown. Head. Clypeus smooth with dorsal 0.6 punctate with punctures separated by 0.5—1.0x their diameter becoming less dense apically; apical margin medially concave Revision of Nearctic Heterischnus (Hymenoptera, Ichneumonidae, Ichneumoninae) 61 Figure 2. Heterischnus bicolorator (Aubert), female A habitus B mesosoma, lateral view C head, frontal view D head, dorsal view E propodeum, dorsolateral view. Scale bars: 5.0 mm (A); 1.0 mm (B-E). to nearly straight with blunted sublateral apices. Supraclypeal area rugulose-punctate. Gena rugulose-punctate ventrally, dorsally smooth with coarse punctures 0.5—1.0x their diameter. Malar space 1.5—1.8x basal mandibular width. Supraclypeal area rugu- lose-punctate. Vertex smooth with coarse punctures separated by 0.5—1.0x their diam- eter. Antenna with 34 flagellomeres. Mesosoma. Mesonotum smooth with coarse punctures separated by 0.1—0.5x their diameter. Scutellum smooth with dense, coarse punctures separated by 0.2—1.0x their diameter. Mesopleuron varying from densely, coarsely punctate to rugulose-punctate. Speculum coarsely punctate dorsally. Ventral division of metapleuron densely, coarsely punctate to rugulose-punctate. Dorsal division of metapleuron finely punctate. Pro- podeum rugulose. Propodeal carination complete, except lateral longitudinal carina obsolete anteriorly. Tarsal claws simple. 62 Brandon Claridge / Journal of Hymenoptera Research 85: 57-79 (2021) Figure 3. Nearctic distribution of Heterischnus bicolorator (Aubert). Metasoma. Postpetiole varying from granulate to rugulose. T2 length 1.4—1.5x posterior width. T2—7 granulate with dense, shallow, punctation becoming sparser and indistinct posteriorly. Gastrocoelus longitudinally rugulose. Thyridium distant from T2 anterior margin by 2.0—3.0x thyridial length. Male. Not examined (not known from Nearctic region). Material examined. Non-type material: Canava * 19; British Columbia, Stone Mountain Park; 5500 ft; 20.vii.1973; H. & M. Townes; EMUSENT00000302 ¢ 19; same collection data as preceding; 22.viii.1973; H. & M. Townes; EMUS00000151. USA © 19; Alaska, Umiat; 20.vii.1947; C. Schultz; USNM. Distribution and biology. Heterischnus bicolorator is known from western Europe and as far east as Chita Oblast in Russia (Yu et al. 2016). In the Nearctic, it is known only from two localities in Alaska and British Columbia (Fig. 3), but is likely present through- out the intervening areas, including the Yukon Territory. No host information is known. Comments. The three Nearctic specimens examined agree with both the original description (Aubert 1965) and images of a syntype specimen. No significant color or morphological differences could be found that would indicate that the examined Nearctic specimens are not conspecific with Palearctic specimens of H. bicolorator. Heterischnus coloradensis (Cushman) Figs 4-6 Ischnopsidea coloradensis Cushman, 1920: 253. Holotype: 2 [USNM]. Not examined. Diagnosis. Heterischnus coloradensis (Cushman) is chromatically and morphologically similar to H. huardi but can be distinguished from the latter and other Nearctic species Revision of Nearctic Heterischnus (Hymenoptera, Ichneumonidae, Ichneumoninae) 63 Figure 4. Heterischnus coloradensis (Cushman) female A habitus B mesosoma, lateral view C head, fron- tal view D head, dorsal view E propodeum, dorsolateral view. Scale bars: 5.0 mm (A); 1.0 mm (B-E). by a combination of the following: 1) male clypeus dark reddish-brown to black; 2) flagellomeres 10/11—12/13 dorsally white in female; 3) supra-antennal area rugulose- punctate; and 4) first lateral area of propodeum rugulose-punctate. Description. Female (Fig. 4). Body length: 6.8-8.7 mm. Fore wing length: 4.2— 5.1 mm. Color. Head black. Mandible yellowish-white with brown apex. Antenna dark brown with flagellomeres 10/11—12/13 dorsally white. Mesosoma black with following areas white: occasionally anterior margin of pronotum (25% of specimens), posterior 0.2 of dorsal margin of pronotum, usually subalar prominence (60% of specimens), and tegula. Fore and middle legs light brownish-red except for tarsomere 5 brown. Hind leg brownish-red except for basal 0.1 of tibia white, apical 0.2 of tibia brown, tar- someres brown. Metasoma black to dark brown. Wing membrane clear; basal 0.1—0.2 of wing with veins white, remaining sections brown. 64 Brandon Claridge / Journal of Hymenoptera Research 85: 57-79 (2021) Head. Clypeus smooth, basally with fine punctures separated by 0.5—1.0x their di- ameter becoming less dense apically; ventral margin with sublateral apical projections subobsolete to obsolete. Malar space 1.5—2.0x basal mandibular width. Supraclypeal area rugulose-punctate. Gena smooth, coarsely punctate with punctures separated by 0.2—1.5x their diameter. Supra-antennal area rugulose-punctate. Vertex smooth, finely punctate with punctures separated by 0.5—2.0x their diameter. Antenna with 32-34 flagellomeres. Mesosoma. Mesonotum smooth, with punctures separated by 0.5—2.0x their di- ameter. Scutellum smooth, finely punctate with punctures separated by 1.0—2.0x their diameter. Mesopleuron densely, coarsely punctate with punctures confluent to sepa- rated by about 0.5x their diameter becoming more sparse dorsally; tendency in some specimens to form lateral rugulae. Speculum coarsely punctate dorsally, smooth ven- trally. Ventral division of metapleuron rugulose-punctate. Dorsal division of metapleu- ron with a few scattered punctures. Propodeum overall rugulose-punctate with areola and posterodorsal face rugulose; carination complete. Tarsal claws simple. Metasoma. Postpetiole rugulose-punctate. T2 length 1.0—1.2x posterior width. T2-7 granulate with dense, shallow punctures; punctation becoming sparser and in- distinct posteriorly. Gastrocoelus rugulose-granulate. Thyridium distant from T2 ante- rior margin by 0.5—2.0x thyridial length. Male (Fig. 5). Body length 6.8-9.1 mm. Fore wing length: 4.3-5.6 mm. As in female except for: yellowish-white markings on mesosoma more extensive. Material examined. Paratype: USA * 19; Colorado, Larimer Co., Forrester’s; 19.vii.1895; C. F & N. E. Baker; USNM paratype 22850. Non-type material: USA * 19; California, Modoc Co. 1 mile N of Stough Reser- voir; [41.5767, -120.2538], 15.vi.1963; UCDC ¢ 19; California, Modoc Co., Cedar Pass; [41.5623, -120.2688]; 29.vi.1955; D. L. Dahlsten; UCDC ° 19; California, Ne- vada Co., Sagehen Cr. near Hobart Mills; [39.4342, -120.2048]; 15.vii.1964; M. E. Ir- win; UCRCENT529785 ¢ 19; Colorado, Grand Co., Phantom Valley, Rocky Moun- tain National Park; 9400 ft; [40.2833, -105.8505]; 16.vi.1948; H., M., G.,D. & J. Townes; EMUSENT00000417 * 12, 34°33 Colorado, Routt Co., Steamboat Springs; [40.4857, -106.8309]; 6.viii.1948; H., M., G.,D. & J. Townes; EMUSENT00000722, EMUSENT00000132, EMUSENT00000207, EMUSENT00000073 ¢ 14; same col- lection data as preceding; 5.viii.1948; EMUSENT00000345 « 14; Idaho, Oneida Co., 3 mi. S of Roy Summit; [42.2635, -112.7653]; 6.vii.1972; G. E Knowlton; EMUSE- NT00000137 © 14; Idaho, Blaine Co., 9 mi. SW Bellevue; [43.3353, -114.2901]; 28.viii.1965; J. S. Buckett; UCDC ¢ 19; Idaho, Boise Co., Idaho City; [43.82813, -115.8341]; 9.vi.1978; H. & M. Townes; EMUSENT00000777 * 329; same col- lection data as preceding; 13.vi.1978; EMUSENT00000258, EMUSENT00000317, EMUSENT00000225 ¢ 1929; same collection data as preceding; 14.vi.1978; EMUSENT00000192 * 243; Idaho, Custer Co., nr. Stanley; [44.2161, -114.9353]; 2.viii.1978; H. & M. Townes; EMUSENT00000253, EMUSENT00000206 ¢ 160; same collection data as preceding; 7.viii. 1978; EMUSENT00000288 ¢ 244; same col- lection data a preceding; 8.viii.1978; EMUSENT00000719, EMUSENT00000297 e 192; Idaho, Oneida Co., Rock Creek; [42.4320, -114.3054]; 17.vii.1972; G. E Revision of Nearctic Heterischnus (Hymenoptera, Ichneumonidae, Ichneumoninae) 65 Figure 5. Heterischnus coloradensis (Cushman) male A habitus B head, frontal view. Scale bars: 5.0 mm (A); 1.0 mm (B). Figure 6. Distribution of Heterischnus coloradensis (Cushman). Knowlton; EMUSENT00000138 ¢ 14; same collection data as preceding; 6.vii.1972; EMUSENT00000224 ¢ 14; Montana, Madison Co., 16 miles S. of Cameron; [45.0604, -111.6656]; 18.vii.1971; UCDC * 329; Montana, Gallatin Co., Boze- man; [45.6771, -111.0428]; 30.vi.1978; R., B. & C. Dasch; EMUSENT00000629, EMUSENT00000056, EMUSENT00000194 ¢ 499; same collection data as preceding; 7.vii.1978; EMUSENT00000193, EMUSENT00000077, EMUSE- NT00000566, EMUSENT00000357 * 14; Nevada, Elko Co., Elko; [40.8385, -115.7628]; 21.viii.1964; FE S. Buckett; UCDC * 19; Nevada, Elko Co., Tuscarora; [41.3146 -116.2233]; 5.vi.1978; H. & M. Townes; EMUSENT00000393 ¢ 19; Ne- vada, Storey Co., Virginia City; [39.3093, -119.6499]; 14.vi.1951; W. J. Wall; UCDC ¢ 12; Oregon, Union Co., Mt. Emily; [45.4379, -118.0913]; 03-11.vi.1987; T. R. 66 Brandon Claridge / Journal of Hymenoptera Research 85: 57-79 (2021) Torgersen, EMUSENT00000420 * 19; Utah, Box Elder Co. Willard Peak.; 9000 ft; [41.4210, -112.0561]; 25.vii.1960; G. E. Bohart; EMUSENT00000347 * 299; Utah, Cache Co., Black Smith Fork Canyon; [41.6278, -111.8040]; 1-6.vii.1964; W. J. Hanson; EMUSENT00000391, EMUSENT00000108 * 19; Utah, Cache Co., North Logan; [41.7706, -111.8045]; 25-31.v.1983; C. R. Nelson; EMUSE- NT00000030 * 14; Utah, Cache Co., Tony Grove; 2290 m; 41.8884, -111.6571; 18.v.-1.vi.2019; B. Claridge; Malaise trap; EMUSENT00000547 * 19; Utah, Cache Co., Tony Grove Canyon; [41.8902, -111.6371]; 25.viii—2.ix.1976; W. J. Hanson; EMUSENT00000026 ¢ 13; Wyoming, Albany Co., Pole Mountain; 41.22, -105.45; 13—20.vii.2013; Malaise trap, ungrazed short grass prairie; L. Haimowitz, H, Aguirre; EMUSENT00004739. Distribution and biology. Collecting dates span mid-May to early September, although the greatest number of records are from July and August. Heterischnus colo- radensis occurs from the Rocky Mountains west to the eastern slopes of the Sierra Ne- vada Range (Fig. 6). Throughout its range, H. coloradensis is sympatric with H. huardi. No host information is known. Comments. [n addition to the examined paratype, a specimen that was compared with the holotype by Henry Townes was examined. Heterischnus huardi (Provancher) Figs 7—9 Posocentrus huardi Provancher, 1875: 273. Lectotype: 2 [University of Laval Entomol- ogy Collection, Quebec, Canada]: designated by Townes (1939). Not examined. Phaeogenes recticaudus Provancher, 1886: 42. Holotype: 2 [University of Laval Entomol- ogy Collection, Quebec, Canada]: Synonymized by Townes (1944). Not examined. Ischnopsidea alberta Cushman, 1927: 1. Holotype: 2 [USNM]: Synonymized by Townes (1944). Not examined. Diagnosis. Heterischnus huardi can be distinguished from other Nearctic species by the combination of the following: 1) clypeus yellowish-white in males; 2) female flagellum without any trace of yellowish-white banding; 3) supra-antennal area smooth with fine, shallow punctures; 4) and first lateral area of propodeum varying from entirely smooth to smooth and rugulose, but never rugulose-punctate as in H. coloradensis. Description. Female (Fig. 7). Body length: 5.5—8.8 mm; fore wing length: 3.8— 5.6 mm. Color. Head usually black, infrequently varying from dark reddish-brown to dark brown. Mandible yellowish-white except for dark brown apex. Antenna brown. Meso- soma overall black to dark brown, with the following areas yellowish-white: dorsal margin of pronotum, subalar prominence, and tegula; specimens from California and Oregon usually with mesonotum, scutellum, mesopleuron, and ventral division of metapleuron brownish-red to varying extents. Fore and middle legs with coxae, Revision of Nearctic Heterischnus (Hymenoptera, Ichneumonidae, Ichneumoninae) 67 Figure 7. Heterischnus huardi (Provancher) female. Eastern and western Nearctic dark phase (A-E) A habitus B mesosoma, lateral view C head, frontal view D head, dorsal view E propodeum, dorsolateral view F western Nearctic reddish phase H. huardi female habitus. Scale bars: 5.0 mm (A, F); 1.0 mm (B-E). trochanters and trochantelli white to light reddish-brown; tibiae and femora light red- dish-brown; tarsomeres 1-4 light reddish-brown; tarsomere 5 brown. Hind leg with coxa and trochanter light reddish-brown; trochantellus white to light reddish-brown; femur light reddish-brown; tibia light reddish brown with apical 0.5 dorsally brown; tarsomere 1 brown with basal 0.3 varying from light reddish-brown to brown; tar- someres 2—5 brown. Metasoma varying from dark brown to black; one specimen from Nojoqui Falls Park, California with T1 medially brownish-red. Wing: membrane clear; basal 0.2 of wing with veins white, remaining vein sections brown. Head. Clypeus smooth, dorsally with fine punctures separated by 0.5—1.0x their diameter becoming less dense ventrally; ventral margin truncate medially and with sublateral projections varying from blunt to sharp. Supraclypeal area rugulose-punc- 68 Brandon Claridge / Journal of Hymenoptera Research 85: 57-79 (2021) tate with punctures separated by 0.5—1.5x their diameter, becoming less dense laterally. Gena smooth, finely punctate with punctures separated by 3.0—5.0x their diameter. Malar space 1.0—1.2x basal mandibular width. Supra-antennal area smooth and finely punctate with punctures separated by 1.0—3.0x their diameter. Vertex smooth and finely punctate with punctures separated by 1.0—3.0x their diameter. Antenna with 25-29 flagellomeres. Mesosoma. Mesonotum smooth and finely punctate with punctures separated by 0.5—2.0x their diameter. Scutellum smooth and finely punctate with punctures sepa- rated by 2.0—3.0x their diameter. Mesopleuron punctate with punctures separated by 0.2—1.0x their diameter, tendency in some specimens to form lateral rugulae. Specu- lum smooth with several scattered punctures. Ventral division of metapleuron punctate with punctures separated by 0.2—1.0x their diameter. Dorsal division of metapleu- ron finely punctate separated by 0.4—1.0x their diameter. Propodeum overall smooth, pleural area rugulose-punctate; carination complete, except lateral longitudinal carina absent anteriorly. Tarsal claws simple. Metasoma. MS1 with postpetiole smooth anteriorly, posteriorly longitudinally ru- gulose laterally. T2 length 1.3—1.4x posterior width. T2—7 granulate with dense shal- low punctation becoming sparser and indistinct posteriorly. Gastrocoelus longitudinal- ly rugulose. Thyridium distant from T2 anterior margin by 2.5—4.0x thyridial length. Male (Fig. 8). Body length: 5.4-8.9 mm; fore wing length: 3.8-5.6 mm. As in female except for: clypeus usually (90% of specimens) white except for dark brown to black apical margin and medial mark extending from apical 0.1 up to 0.3; infrequently most of clypeus dark brown to black with white area only present medially or as dorso- lateral markings; very rarely clypeus entirely dark brown. Malar space shorter (0.8—1.0 basal mandibular width.) Material examined. Non-type material: Canapa * 192; Alberta, Edmonton; [53.5487, -113.4927]; 1.iv.1924; Owen Bryant; USNM ¢ 19; Alberta, Seebe, K.EE.S; 29.viii. 1958; “ex Pterophoridae willow’; 57-A-1575-047; 314; CNCI ¢ 329; Alberta, Sturgeon, L. Rt. 34; [53.6316, -113.6161]; 26.vi.1977; B. & C. Dasch; EMUSE- NT00000163, EMUSENT00000567, EMUSENT00000254 * 13; British Colum- bia, Craigallachie, 22 km E Sicamous; 350 m; [50.8397, -118.9738]; 28.vi.—14. viii.1988; S. & J. Peck; EMUSENT00000453 © 544; British Columbia, Dome Creek; [53.7503, -121.1034]; 27.viii.1973; H. & M. Townes; EMUSENT00000092, EMUSENT00000178, EMUSENT00000088, EMUSENT00000268, EMUSE- NT00000718 © 14; British Columbia, Fort Nelson; [58.8040, -122.6981]; 25. viii.1973; H. & M. Townes; EMUSENT00000538 * 11929; British Columbia, Mt. Robson Provincial Park; [53.0352, -119.2310]; 23.vii.1977; B. &¢ C. Dasch; EMUSE- NT00000477, EMUSENT00000195, EMUSENT00000568, EMUSENT00000213, EMUSENT00000479, EMUSENT00000027, EMUSENT00000343, EMUSE- NT00000447, EMUSENT00000358, EMUSENT00000122, EMUSENT00000536 ¢ 14; British Columbia, Stone Mountain Peak; 3800 ft; [58.5862, -124.7642]; 13. vii.1973; H. & M. Townes; EMUSENT00000628 ¢ 19; same collection data as pre- ceding; 17.vii.1973, EMUSENT00000241 * 19; British Columbia, Y.N.P, “End of Revision of Nearctic Heterischnus (Hymenoptera, Ichneumonidae, Ichneumoninae) 69 | ry Figure 8. Heterischnus huardi (Provancher) male A habitus B head, frontal view. Scale bars: 5.0 mm (A); 1.0 mm (B). Figure 9. Distribution of Heterischnus huardi (Provancher). Ire River Road”; 10.viii.1956; “ex. Platyptilia sp. A. fir.”; 56-18-1148-01; 406; CNCI ¢ 229; Ontario, Algonquin Provincial Park; [45.5539, -78.5965]; 08.viii.1983; B. & C. Dasch; EMUSENT00000344, EMUSENT00000328 ¢ 19; Ontario, Cumber- land; [45.5163, -75.4060]; 3.v.1975; L. Ling; EMUSENT00000752 ¢ 19; same col- lection data as preceding; 8.v.1975; EMUSENT00000541 ¢ 19; same collection data as preceding; 10.v.1975; EMUSENT00000661 ¢ 19; same collection data as preced- ing; 11.v.1975; EMUSENT00000032 * 19; same collection data as preceding; 6. vi.1975; EMUSENT00000033 * 19; same collection data as preceding; 8.vi.1975; EMUSENT00000063 * 1; same collection data as preceding; 9.vii.1975; EMUSE- NT00000631 © 244; same collection data as preceding; 13.vii.1975; EMUSE- 70 Brandon Claridge / Journal of Hymenoptera Research 85: 57-79 (2021) NT00000482, EMUSENT00000061 © 244; same collection data as preceding; 18.vii.—10.viii.1975; EMUSENT00000121, EMUSENT00000512 ¢ 19; Saskatche- wan, Prince Albert National Park; [53.9143, -75.4060]; 19.vii.1941; J. G. Rempel; EMUSENT00000508 ¢ 19; same collecting data as preceding; 20.vii.1941; EMUSE- NT00000418 ¢ 19; Yukon Territory, Burwash Flats Mi. 1105 Alcan Hwy.; [61.3536, -138.9976]; 4.vii.1977; B. & C. Dasch; EMUSENT00000506 ¢ 19; Yukon Territory, Teslin L. Mi. 820 Alcan Hwy.; [60.1745, -132.7143]; 30.vi.1977; B. & C. Dasch; EMUSENT00000603 ¢ 19; same collecting data as preceding; 1.vii.1977; EMUSE- NT00000167. USA ® 49 9; Alaska, Municipality of Anchorage, Anchorage; [61.1993; 149.8533]; 6-12.vii Peter A. Rush; EMUSENT00000028, EMUSENT00000720, EMUSENT00000058, EMUSENT00000690 ¢ 29 9; same collection data as preced- ing; 16—20.vii.1976; EMUSENT00000089, EMUSENT00000118 ¢ 19; same col- lection data as preceding; 20—23.vii.1976; EMUSENT00000390 © 399; Alaska, Delta Junction; [64.0377; -145.7301];7.vii.1977; B. & C. Dasch; EMUSE- NT00000228, EMUSENT00000136, EMUSENT00000633 ¢ 1; Alaska, Ketchi- kan Gateway Borough, Ketchikan; [55.3465; -131.643] 16.viii.1959; R. H. Washburn e 19; Alaska, Tok; [63.3361; -142.9855]; 5.vii.1977; B. & C. Dasch; EMUSE- NT00000717 © 19; California, Big Oak Flat Road, nr. Crane Crk., Yosemity Na- tional Park; [37.7517; -119.8004]; 28.vi.1959; D. W. Price; UCDC ¢ 244; Califor- nia, Marin County, Inverness; [38.0998; -122.8619]; 6.x.1946; H. K. Townes; EMUSENT00000287, EMUSENT00000389 ¢ 19; California, Tulare County, Min- eral King Road; [36.4500; -118.5945]; 16.v.1970; B. Knapp; EMUSENT00000449 1Q; California, Santa Barbra County, Montecito; [34.4368; -119.6321]; 08.iv.1997— 13.iv.1997; A. Calderwood, R. Doutt; EMUSENT00000078 ¢ 19; California, Santa Barbra County, Nojoeui Falls Park; (34.5344; -120.1776]; 3.vii.1959; R. M. Bohart; UCDC ¢ 19; Colorado; Doolittle Ranch, Mt. Evans; [39.6752; -105.6011]; 9800 ft; 20.vii.1964; B. & C. Dasch; EMUSENT00000688 ¢ 19; same collection data as pre- ceding; 12.vii.1973; EMUSENT00000753 * 29; Colorado, Jackson County, Gould; [40.5271; -106.0300]; 6.viii.1974; H. & M. Townes; EMUSENT00000212, EMUSENT00000062 * 19; Colorado, Grand County, Grand Lake; [40.2518; -105.8301]; 2.viii.1948; H. & M. Townes; EMUSENT00000510 ¢ 19; same collect- ing data as preceding; H., M., G.,D. & J. Townes; EMUSENT00000658 ¢ 19; Colo- rado, Rabbit Ears Pass; [40.3847; -106.6117]; 9500 ft; 7.viii.1948; H., M., G. & D. Townes; EMUSENT00000422 © 19; Idaho, Galena Summit, nr. Stanely; [43.8702; -114.7134]; 8700 ft; 4.viii.1978; H. & M. Townes; EMUSENT00000778 © 299; Idaho; Boise County; Idaho City; [43.82813; -115.8341]; 13.vi.1978; H. & M. Townes; EMUSENT00000299, EMUSENT00000269 ¢ 19; Idaho; Boise County, Lowman; [44.0807; -115.6202]; 4000 ft; 11.vi.1978; H. & M. Townes; EMUSE- NT00000723 * 2929; same collection data as preceding; 12.vi.1978; EMUSE- NT00000331, EMUSENT00000211 ¢ 39 9; same collection data as preceding; 6000 ft; 13.vi.1978; EMUSENT00000180, EMUSENT00000242, EMUSENT00000751 ¢ 12; same collection data as preceding; 4000 ft; 14.vi.1978; EMUSENT00000090 14, 299; Idaho, Boise County, Lowman; [44.0807; -115.6202]; 6.viii.1978; H. & M. Townes; EMUSENT00000478, EMUSENT00000450, EMUSENT00000029 « Revision of Nearctic Heterischnus (Hymenoptera, Ichneumonidae, Ichneumoninae) Fak 14; same collection data as preceding; 3.viii.1978 ¢ 19; Idaho, nr. Stanley; [44.2159; -114.9352]; 5.viii.1978; H. & M. Townes; EMUSENT00000570 © 19; Maine, 4.5 mi. W Bangor; [44.7994; -688326]; 12.viii.1986; B. & C. Dasch; EMUSE- NT00000416 * 19; same collection data as preceding; 13.viii.1986; EMUSE- NT00000086 ¢ 29 9; Maine, Cumberland County, Sebado Lake; [43.9303; -70.5678]; 12.v.1919; B. W. Hall; EMUSENT00000093, EMUSENT00000183 ¢ 229; Mas- sachusetts; Mt. Greylock; [42.6375; -73.1663]; 02.viii.1958; B. & C. Dasch; EMUSE- NT00000283, EMUSENT00000282 ¢ 19; Michigan, Emmet County;,Mackinaw City; [45.7776; -84.7283]; 04.viii.1980; B. & C. Dasch; EMUSENT00000313 ¢ Lich, 19; Michigan, Iron County, Pentoga Park; [46.0387; -88.5105]; 01.viii.1980; B. & C. Dasch; EMUSENT00000689, EMUSENT00000749 * 12; New York, Ithaca; [42.4443; -76.5017]; 12.vi.1952; C. Dasch; EMUSENT00000107 ® 19; same collec- tion data as preceding; 15.vii.1950; EMUSENT00000315 ¢ 19; same collection data as preceding; 22.vii.1950; EMUSENT00000256 244; same collection data as pre- ceding; 7.vii.1951; EMUSENT00000597, EMUSENT00000569 * 12; New York, McLean Bogs; [42.4911; -76.297 1]; 22.v.1953; B. & C. Dasch; EMUSENT00000476 ©2344; New York, Otsego County, Milford Center; [42.5241; -74.9887]; 13.vii.1935; H. K. Townes; EMUSENT00000662, EMUSENT00000452 ¢ 19; New York, One- onta County, Oneonta; [42.4584; -75.0602]; 1900 ft; 18.viii.1935; H. K. Townes; EMUSENT00000183, EMUSENT00000721 * 19; New York, Ulster County, Slide Mountain, [41.9996; -74.3854]; 2800-4000 ft; 25.viii.1936; H. 8& C. Townes; EMUSENT00000481 * 24'3, 229; North Carolina, Macon County, Highlands; (35.0536; -83.1969]; 21.vi.1977; H & M Townes; EMUSENT00000359, EMUSE- NT00000573, EMUSENT00000660, EMUSENT00000148 © 16, 22; same collec- tion data as preceding; 22.vi.1977; EMUSENT00000208, EMUSENT00000633, EMUSENT00000240 *© 399; same collection data as preceding; 23.vi.1977; EMUSENT00000119, EMUSENT00000633 © 19; same collection data as preced- ing; 24.vi.1977; EMUSENT00000210 » 14; same collection data as preceding; 26.vi.1977; EMUSENT00000598 * 19; North Carolina, Mt. Mitchell; [35.7668; -82.2653]; 5500 ft; 25.vii.1968; C. Dasch; EMUSENT00000542 © 19; North Caro- lina, Buncombe County, Pisgah Mountain; [35.4197; -82.7484]; 4800-5300 ft; 21. vi.1940; H & M Townes; EMUSENT00000513 © 14; Ohio, McAllister Biological Station; [41.4478; -83.7789]; 18—21.vi.1986; B. & C. Dasch; EMUSENT00000198 ¢ 12; Oregon, Benton County, Corvalis; [44.5630; -123.2644]; 02.vi.1978; H. & M. Townes; EMUSENT00000043 * 19; same collection data as preceding; 11.v.1987; EMUSENT00000045 ¢ 192; same collection data as preceding; 19-20.vi.1965; C. Dasch; EMUSENT00000329 * 19; Oregon; Jackson County, Hyatt Reservoir; (42.1683; -122.4634]; 29.vi.1978; H. & M. Townes; EMUSENT00000252 © 13; Oregon, Pierce County, Hyatt Reservoir; [42.1683; -122.4634]; 29.vi.1978; H. & M. Townes; EMUSENT00000356 * 14; Oregon, Union County, Mt. Emily; [45.4379; -118.0913]; 06—21.viii.1987; T. R. Torgersen; EMUSENT00000166 ¢ 49 9; Oregon, Mt. Hood; [45.3269; -121.7136]; 3500 ft; 19.vii.1978; H. & M. Townes; EMUSE- NT00000177, EMUSENT00000342, EMUSENT00000296, EMUSENT00000327 ¢ 19; same collection data as preceding; 20.vii.1978; EMUSENT00000165 ¢ 19; 72 Brandon Claridge / Journal of Hymenoptera Research 85: 57-79 (2021) same collection data as preceding; 24.vii.1978; EMUSENT00000223 ¢ 19; same col- lection data as preceding; 26.vii.1978; EMUSENT00000227 * 329; same collection data as preceding; 30.vii.1978; EMUSENT00000386, EMUSENT000000386, EMUSENT00000133, EMUSENT000000226 * 19; Oregon, Josephine County, Selma; [42.2787; -123.6152] 20.v.1978; H. & M. Townes; EMUSENT00000480 ¢ 22.2; same collection data as preceding; 27.v.1978; EMUSENT00000075, EMUSE- NT00000656 * 19; Pennsylvania, Forest County, 1 mi. N Marienville; [41.4794; -79.1101]; ; 3.vii.1980; C. Dasch; EMUSENT00000236 © 19; Pennsylvania, Forest County, 4 mi. N Marienville; [41.5104; -79.0688]; 03.vii.1980; C. Dasch; EMUSE- NT00000419 © 229; Pennsylvania, Tioga County, Gaines; [41.7520; -77.5572]; 23-26.vii.1994; B. & C. Dasch; EMUSENT00000059, EMUSENT00000179 ¢ 19; same collection data as preceding; 26.vii.1994; EMUSENT00000239 14; same col- lection data as preceding; 30.vi.1980; EMUSENT00000338 © 19; Pennsylvania, Mercer County, Mercer; [41.2265; -80.2393]; 12-15.vi.1995; B. & C. Dasch; EMUSENT00000149 ¢ 14; Utah, Cache County, Logan, USU campus; 41.74194; -111.81183; 1460 m; 8.vii.2019; B. Claridge; EMUSENT00000021 ¢ 229; Utah, Cache County, Uinta-Wasatch-Cache National Forest, Tony Grove; 41.8876; -111.6009; 2290 m; 03-17.viii.2019; B. Claridge; EMUSENT00000202, EMUSE- NT00000232 ¢ 19; Utah, Cache County, UWC National Forest, Tony Grove; 41.8884; -111.6299; 17-31.viii.2019; B. Claridge; EMUSENT00003712 ¢ 14, 19; Washington, Pierce County, Ashford; [46.7579; -122.0304]; 6.vii.1940; H. & M. Townes; EMUSENT00000483, EMUSENT00000630 © 19; same collection data as preceding; 11.vii.1940; EMUSENT00000360 © 19; same collection data as preced- ing; 20.vii.1940; EMUSENT00000540 ¢ 19; Washington, Barnes State Park; [46.2724; -122.909]; 12.viii.1940; H. & M. Townes; EMUSENT00000060 * 9; Washington, Mt. Rainier; 2900 ft; 12.vii.1940; H. & M. Townes; EMUSE- NT00000750 © 19; same collecting data as preceding; 7.vii.1940; EMUSE- NT00000693 ¢ 19; same collecting data as preceding; 4200 ft; 15.vii.1940; EMUSE- NT00000301 © 19; same collecting data as preceding; 4700 ft; 21-vii.1940; EMUSE- NT00000330 ¢ 19; same data as preceding; 5000 ft; 14.vii.1940; EMUSE- NT00000543 © 19; same data as preceding; 9.vii.1940; EMUSENT00000120 ¢ 19; same data as preceding; 5300 ft; 16.viii.1940; EMUSENT00000332 ¢ 19; same data as preceding; 17.viii.1940; EMUSENT00000571 ¢ 19; same data as preceding; 5700 ft; 8.vii.1940; EMUSENT00000362 ¢ 12; Washington, Mt. Rainier National Park, Paradise; [46.7853; -121.7349]; ; 26—27.vi.1987; B. V. Brown; EMUSENT00000600 ©2499, 299; West Virginia, Bickle Knob; [38.9343; -79.7314]; 4020 ft; 15.vii.1979; B. & C. Dasch; EMUSENT00000691, EMUSENT00000103, EMUSENT000003 14, EMUSENT00000687 * 504,19; same data as preceding; 17.vii.1979; EMUSE- NT00000316, EMUSENT00000599, EMUSENT00000284, EMUSENT00000057, EMUSENT00000042, EMUSENT00000147 * 12; West Virginia; Randolph Coun- ty, Bowden; [38.9088; -79.7098]; 14—-17.vii.1992; B. & C. Dasch; EMUSE- NT00000146 © 19; same collection data as preceding; 21—22.vii.1982; EMUSE- NT00000104 © 19; same collection data as preceding; 23—24.vii.1982; EMUSE- Revision of Nearctic Heterischnus (Hymenoptera, Ichneumonidae, Ichneumoninae) p3 NT00000044 © 14,19; same collection data as preceding; 25. vii. 1982; EMUSENT000000387, EMUSENT00000776 © 19; same collection data as preceding; 7-9.v.1993; EMUSENT00000238 ¢ 19; same collection data as preced- ing; 16.vii.1979; C. Dasch; EMUSENT00000117 244, 19; West Virginia, Dolly Sods Area; [39.0447; -79.3438]; 26.vii.1982; B. & C. Dasch; EMUSENT00000255, EMUSENT00000392, EMUSENT00000627 ¢ 14; West Virginia, Pendleton Coun- ty, Spruce Knob; [38.7001; -79.5328]; 4862 ft; 18.vii.1979; B. &¢ C. Dasch; EMUSE- NT00000209 ¢ 49 9; same collection data as preceding; 19.vii.1979; B. & C. Dasch; EMUSENT00000537, EMUSENT00000747, EMUSENT00000659, EMUSE- NT00000074 Distribution and biology. Heterischnus huardi is the most widely distributed North American Heterischnus species. It ranges from the eastern US and throughout Canada to western North America, where it extends north to Alaska, centrally south through the Rocky Mountains, and south along the Pacific Coast through the Sierra Nevada and outer California Coast Ranges. In the California Coast Ranges, it is associ- ated with mixed hardwood forests in the north near Inverness and coastal woodland near Nojoqui Falls Park and Montecito in the south (Kiichler 1978). Bragg (1970) reared five H. huardi specimens from the plume moth, Amblyptilia pica (Walsingham) (Pterophoridae) on Pelargonium (Geraniaceae). Females oviposited into fourth instar prepupae (Bragg 1970). Additionally, two specimens from the CNCI were reared from pterophorids. The first was reared from a Platyptilia pupa collected from Abies (Pinaceae) in British Columbia. The second record was from an unidenti- fied pterophorid pupa collected from Salix (Salicaceae) in Seebe, Alberta. Comments. The color pattern of H. /uardi varies throughout it range. The usual color pattern consists of a dark brown to black head, mesosoma, and metasoma, ex- cluding white markings. Along the Pacific coast in Oregon and California, specimens exhibit varying degrees of brownish-red color on the mesonotum, scutellum, meso- pleuron, and ventral division of the metapleuron. Without stating any supporting evidence, Valemberg (2014) listed Jschnopsidea al- berta Cushman and Phaeogenes recticaudus Provancher as subspecies of H. huardi. The elevation of these names from synonymy to subspecific status is unwarranted. There is no indication from the material examined in this study that any subspecies of H. /uardi can be delimited. The lectotype of H. huardi was not examined, although a specimen that was com- pared with the lectotype by Townes was examined. Heterischnus mexicanus sp. nov. http://zoobank.org/C665E98C-D2E7-4EDB-AGAF-181C26B1DB50 Figs 10-12 Diagnosis. Heterischnus mexicanus sp. nov. can be distinguished from all congeners by a combination of the following: 1) flagellomeres 7/8—11/12 dorsally white in female; 74 Brandon Claridge / Journal of Hymenoptera Research 85: 57-79 (2021) Figure 10. Heterischnus mexicanus sp. nov., holotype female A habitus B mesosoma, lateral view C head, frontal view D head, dorsal view E propodeum, dorsolateral view. Scale bars: 5.0 mm (A); 1.0 mm (BE). 2) propodeum densely and coarsely punctate; and 3) longitudinal carinae of propo- deum reduced or obsolete with at least lateral longitudinal carina posteriorly obsolete. Description. Female (Fig. 10). Body length: 7.7—-8.4mm; fore wing length: 4.4— 4.5 mm. Color. Head black, except following areas white: mandible except for brown apex, venterolateral corners of clypeus, and small ovoid adjacent to eye in supra-antennal area; clypeus varying from black to brownish-red; supraclypeal area brown in one spec- imen; flagellum brown, flagellomeres 7/8—11/12 with ventral surfaces white. Meso- soma overall brownish-red; anterior margin of pronotal collar, dorsal margin of lateral area of pronotum, subalar prominence, and tegula, white; following areas can be dark brown to fuscous: dorsal 0.5 of propleuron, more or less all of remaining non-white areas of pronotum, dorsal region of mesopleuron immediately below tegula, posterior margin of mesoscutum, metanotum, dorsal division of metapleuron, and propodeum. Revision of Nearctic Heterischnus (Hymenoptera, Ichneumonidae, Ichneumoninae) fs) Fore and middle legs with coxae, trochanters, and trochantelli white except for: basal 0.5—0.7 of coxae brownish-red ventrally; femora and tibia brownish-red; tarsomeres light brown to brown. Hind leg brownish-red except for: narrow white apical margin of trochanter; tibia dorsally with irregular light brown maculations; and brown tar- someres. Metasoma varying from completely brown to dark brown, to having median section of Tl, and lateral margins of remaining tergites, brownish-red and remaining areas dark brown. Wing: membrane clear; basal 0.2 of wing with veins white, remain- ing vein sections brown. Head. Clypeus smooth, dorsally with fine punctures separated by 1.0—1.5x their diameter becoming less dense ventrally; ventral margin medially straight and with blunted or obsolete sublateral apices. Supraclypeal area rugulose-punctate with punc- tures separated by 0.5—1.2x their diameter becoming sparser laterally. Gena smooth, finely punctate with punctures separated by 0.5—1.5x their diameter. Malar space 1.5—1.8x basal mandibular width. Supra-antennal area smooth, coarsely punctate with punctures separated by 0.2—0.5x their diameter. Vertex smooth, with coarse punctures separated by 0.5—2.0x their diameter. Antenna with 31-33 flagellomeres. Mesosoma. Mesonotum smooth with coarse punctures separated by 0.5—1.0x their diameter. Scutellum smooth, coarsely punctate with punctures separated by 0.5—1.0x their diameter. Mesopleuron coarsely punctate with punctures separated by 0.2—0.5x their diameter. Speculum smooth, punctation varying between impunctate to coarsely punctate dorsally. Ventral division of metapleuron coarsely punctate with punctures separated by 0.1—0.3x their diameter. Dorsal division of metapleuron varying from smooth to sparsely and finely punctate. Propodeum coarsely punctate with punctures separated by 0.1—0.3x their diameter. Posterior transverse carina and pleural carina present; lateral longitudinal carina absent; remainder of carinae reduced and varying from obsolete to subobsolete medially. Tarsal claws simple. Metasoma. Postpetiole varying from punctate to granulate. T2 length 1.3—-1.4x posterior width. [2—7 granulate with dense shallow, punctures becoming sparser and indistinct posteriorly. Gastrocoelus granulate. Thyridium distant from T2 anterior margin by 0.8—1.2x thyridial length. Male (Fig. 11). Body length 7.0—7.3 mm; fore wing length: 3.9-4.4 mm. As in female, except for: UCDC specimen with small yellowish-white triangular mark be- tween clypeus and ventral corner of eye; clypeus yellowish-white except dark brown ventral margin; apical 0.3 of hind tibia brown. In the Big Bend, Texas specimen hind tibia entirely brown. Material examined. Holotype: Mexico * 9; Coahuila, 6 mi. west of Saltillo; 21.vii.1972; B. & C. Dasch; EMUSENT00000197. Paratypes: MExico ° 44; same collection data as holotype; 20—22.vii.1972; B. & C. Dasch; EMUSENT00000162, EMUSENT000000346, EMUSENT000000326, EMUSENT00000509 ¢ 19; Puebla, 30 mi. SW of Tehuacan; 6800 ft; 12.x.1968; R. H., E. M. Painter; EMUSENT00000692. USA ¢ 19; Arizona; Portal, 28.viii.1974; H. & M. Townes; EMUS0000273 ¢ 19; same data as preceding; 6.ix.1987; EMUSE- NT00000272 © 14; Texas Big Bend; 5000 ft.; 10.viii.1975; S. & J. Peck; EMUSE- NT00000361 * 14, 19; Texas, Government Springs, Grapevine Hills, Big Bend Na- 76 Brandon Claridge / Journal of Hymenoptera Research 85: 57-79 (2021) Figure | 1. Heterischnus mexicanus sp. nov., paratype male (Mexico: Saltillo) A habitus B head, frontal view. Scale bars: 5.0 mm (A); 1.0 mm (B). Figure 12. Distribution of Heterischnus mexicanus sp. nov. tional Park; 5000 ft.; 1.ix.1971; E. E. Grissell & R. E Denno; UCDC « 19; “Ex- chrysanthemum cut flws. fr. Mexico at El Paso”; 1.xi.1963; C. Overmiller; USNM. Distribution and biology. Heterischnus mexicanus sp. nov. is the southernmost ranging Heterischnus species in the New World. Its range spans from the southern bor- der of the USA in Arizona and Texas south to central Mexico in Tehuacan (Fig. 11). Records indicate that adults are active from late July to October and are likely active later in the year in the southern portion of its range as the latter date is from Tehuacan, Mexico. No host records are known for H. mexicanus. Comments. As in H. coloradensis and H. huardi, a few specimens of H. mexicanus sp. nov. show an overall lighter coloration. Etymology. This species epithet refers to its distribution, the majority of which is in Mexico. Revision of Nearctic Heterischnus (Hymenoptera, Ichneumonidae, Ichneumoninae) ries Acknowledgments I am thankful to Dr. Andrew Bennett (CNCI), Dr. Robert Kula (USNM), and Dr. Lynn Kimsey (UCDC) for providing valuable specimens and Dr. Michael Ivie for his assistance searching for specimens at the Montana State University insect collection. I’m also thankful to Dr. Gavin Broad, Dr. Andrew Bennett, and Davide Dal Pos for their helpful comments that greatly improved the manuscript. Finally, I am grateful to Dr. David Wahl for his encouragement and guidance throughout this research. This research was supported by the Utah Agricultural Experiment Station, Utah State University, and approved as journal paper number 9466. References Ashmead WH (1906) Descriptions of new Hymenoptera from Japan. Proceedings of the United States National Museum 30: 169-201. https://doi.org/10.5479/si.00963801.30- 1448.169 Aubert JF (1965) Ichneumonides d’Europe appartenant a dix espéces nouvelles et plusieurs genres nouveaux. Bulletin de la Sociét Entomologique de Mulhouse: 15-23. Bennett AMR, Cardinal S, Gauld ID, Wahl DB (2019) Phylogeny of the subfamilies of Ich- neumonidae (Hymenoptera). Journal of Hymenoptera Research 71: 1-156. https://doi. org/10.3897/jhr.7 1.32375 Bragg, DE (1970) Host records for the parasites Diadegma acuta and Rhexidermus huardi (Hy- menoptera: Ichneumonidae). Annals of the Entomological Society of America 62(1): e339. https://doi.org/10.1093/aesa/63.1.339 Cushman RA (1920) North American Ichneumon-flies, New and Described, with Taxonomic and Nomenclatorial Notes. Proceedings of the United States National Museum 58: 251-— 292. https://doi.org/10.5479/si.00963801.58-2334.25 1 Cushman RA (1927) Miscellaneous notes and descriptions of ichneumon-flies. Proceedings of the United States National Museum 72: 1-22. https://doi.org/10.5479/si.00963801.72-2709.1 Diller E (1981) Bermerkungen zur systematik der Phaeogenini mit einem vorlaufigen catalog der gattungen (Hymenoptera, Ichneumonidae). Entmofauna 2: 93-111. Diller E (1995) Neues iiber Arten aus der Gattung Heterischnus Wesmael 1859 (Hymenoptera, Ichneumonidae, Ichneumoninae, Phaeogenini). Linzer Biologische Beitrage 27: 785-794. Diller E, Shaw MR (2014) Western Palaearctic Oedicephalini and Phaeogenini (Hymenoptera: Ichneumonidae, Ichneumoninae) in the National Museums of Scotland, with distribu- tional data including 28 species new to Britain, rearing records, and descriptions of two new species of Aethecerus Wesmael and one of Diadromus Wesmael. Entomologists’s Ga- zette 65: 109-129. Forster A (1869) Synopsis der Familien und Gattungen der Ichneumonen. Verhandlungen des Naturhistorischen Vereins der Preussischen Rheinlande und Westfalens 25: 135-221. Heinrich GH (1938) Les Ichneumonides de Madagascar. 3. Ichneumonidae—Ichneumoninae. Mémoires l’Academie Malgache 25: 1-138. 78 Brandon Claridge / Journal of Hymenoptera Research 85: 57-79 (2021) Kiichler AW (1978) The map of the natural vegetation of California. Department of Geogra- phy, University of Kansas, Lawrence, Kansas. Lungu-Constantineanu CS, Constanineanu R (2014) New data on ichneumonid hibernation (Hymenoptera: Ichneumonidae) in the Barnova forest massif (Iasi county, Romania). Ro- manian Journal of Biology 59(1): 11-16. Meyer NF (1934) Schlupfwespen die in Russland in den letzten Jahren aus Schadlin- gen gezogen sind. Zeitschrift fiir Angewandte Entomologie 20: 611-618. https://doi. org/10.1111/j.1439-0418.1934.tb00385.x Perkins JF (1959) Hymenoptera. Ichneumonoidea. Ichneumonidae, key to subfamilies and Ichneumoninae—I. Handbook for the Identification of British Insects 7(2ai): 1-116. Provancher L (1875) Les Ichneumonides de Québec. Naturaliste Canadien 7: 263-274. Provancher L (1886) Additions et corrections au Volume II de la Faune Entomologique du Canada. Traitant des Hyménoptéres. Québec, 495 pp. QGIS Development Team (2020) QGIS geographic information system. Open Source Geo- spatial Foundation Project. http://qgis.osgeo.org Rousse P, van Noort S, Diller E (2013) Revision of the Afrotropical Phaeogenini (Ichneumo- nidae, Ichneumoninae), with description of a new genus and twelve new species. ZooKeys 354: 1-85. https://doi.org/10.3897/zookeys.354.5968 Rudow F (1917) Ichneumoniden und ihre Wirte. Entomologische Zeitschrift 31: 66-67. Santos BF, Wahl DB, Rousse P, Bennett AMR, Kula R, Brady S (2021) Phylogenomics of Ichneumoninae (Hymenoptera, Ichneumonidae) reveals pervasive morphological conver- gence and the shortcomings of previous classifications. Systematic Entomology 46: 704— 724. https://doi.org/10.1111/syen.12484 Sedivy J (1986) The hosts of Ichneumon flies in Europe (Hymenoptera, Ichneumonidae). Acta Entomologica Bohemoslovaca 83(1): 10-23. Selfa J, Diller E (1994) Illustrated key to the Western Palearctic genera of Phaeogenini (Hyme- noptera, Ichneumonidae, Ichneumoninae). Entmofauna 15(20): 237-251. Selfa J, Diller E (1997) A new species of Heterischnus Wesmael, 1859, from the Western Palearc- tic Region (Hymenoptera, Ichneumonidae, Ichneumoninae). Entomofauna 18: 469-476. Townes HK (1939) Corrections to the Gahan and Rohwer lectotypes of Provancher’s Ichneu- monidae (Hymenoptera). Canadian Entomologist 71: 91-95. https://doi.org/10.4039/ Ent7191-4 Townes HK (1944) A catalogue and reclassification of the Nearctic Ichneumonidae (Hyme- noptera). Part 1. The subfamilies Ichneumoninae, Iryphoninae, Cryptinae, Phaeogeninae and Lissonotinae. Memoirs of the American Entomological Society 11: 1-477. Uchida T (1956) Neue oder bisher unbekannte Ichneumoniden aus Japan und seinen Umgeg- enden (I). Insecta Matsumurana 20: 57-76. Valemberg J (2014) Les Heterischnus Palearctiques (Hymenoptera: Ichneumonidae: Ichneu- moninae: Phaeogenini: Heterischina). Clefs dichotomiques. Supplément au Bulletin de la Société Entomologique du Nord de la France 351: 1-44. Viereck HL (1914) Type species of the genera of Ichneumon flies. United State National Mu- seum Bulletin No. 83, 186 pp. https://doi.org/10.5479/si.03629236.83. 1 Revision of Nearctic Heterischnus (Hymenoptera, Ichneumonidae, Ichneumoninae) fay) Wesmael C (1859) Remarques critiques sur diverses espéces d’Ichneumons de la collection de feu le Professor J.L.C. Gravenhorst, d'un court appendice Ichneumonlogique. Memoires Couronnes Académie Rorale Sciences Belgique 8: 1-99. https://www.biodiversitylibrary. org/page/42580283 Yu DSK, Achterberg C van, Horstmann K (2016) Taxapad 2016, Ichneumonoidea 2015. Da- tabase on flash-drive, Nepean. http://www.taxapad.com Supplementary material | Nearctic Heterischnus material examined Author: Brandon Claridge Data type: occurences Explanation note: The .csv file contains the material examined section in table format and follows the Darwin Core guidelines. This file is intended to help readers better use the material examined section and for uploading the occurrence data to GBIF. Copyright notice: This dataset is made available under the Open Database License (http://opendatacommons.org/licenses/odbl/1.0/). The Open Database License (ODbL) is a license agreement intended to allow users to freely share, modify, and use this Dataset while maintaining this same freedom for others, provided that the original source and author(s) are credited. Link: https://doi.org/10.3897/jhr.85.67792.suppl1