Penthetria heteroptera (Say), 1823

Fitzgerald, Scott J., 2021, Penthetria Meigen (Diptera: Bibionidae): Revision of the New World species and world catalog, Zootaxa 4926 (4), pp. 451-500 : 472-475

Penthetria heteroptera (Say), 1823

( Figs. 1 , 16–21 , 38, 40 , 50–51 , 57 , Map 3 )

Penthetria atra Macquart, 1834: 175 (by monotypy). Pennsylvania, USA. [HT male BMNH; examined].

Penthetria longipes (Loew), 1858a: 109 (originally described in Plecia ). Louisiana, USA. [type could not be located for study; not at MCZC (online database accessed 2019) or ZMHB ( Werner, 1999)]. ( McAtee (1921) suggested this species may be conspecific with P. heteroptera and it was treated as such by Hardy (1945) though without discussion of the synonymy).

Penthetria lugubris Harris, 1835: 596 . Massachusetts, USA. Nomen nudum.

Type Material. Male , USA: “ Maryland ” ( Say 1823, as Bibio heteropterus ) .

Like many of Thomas Say’s types, the type (s) of this species could not be located and may be lost or destroyed. Evenhuis (1997) notes that due to exchanges with colleagues, some of Say’s types still exist in a handful of collections. However, the type (s) of P. heteroptera were not found at ANSP, BMNH, MZHF, NHMW, or OXUM. Despite the fact that the type of P. heteroptera could not be studied, the identity of this species seems sound as it is the only species of Penthetria currently known to occur in the eastern half of the United States, which includes the type locality in Maryland (material from Maryland has been studied to help establish the concept of P. heteroptera utilized herein (e.g., see Figs. 16, 20–21 , 38 , and material examined). It is noteworthy though that the most eastern record of P. yakima is Ontario, Canada, and it is possible that this species does exist in the northeastern USA.

Material Examined. CANADA: ALBERTA: Waterton Lakes , 29 VIII 1926, N. Criddle, 1M ( CNCI) ; Elkwater Park , 15 VIII 1952, L.A. Konotopetz, 1M ( CNCI) ; Edmonton , 7 IX 1936, F.O. Morrison, 1M ( BYUC) ; BRITISH COLUMBIA: mi 233 Al. Hwy, 29 VIII 1948, W. R. Mason, 1M, 1F (in copula) ( CNCI) ; Alaska Hwy, Lum & Almer , 58°N, Aug 29 1948, Mason & Hughes, 1M ( CNCI) ; MANITOBA: Napinka , 24 VIII 1927, R. M. White, 1M ( CNCI) ; Aweme , 27 VIII 1925, R. D. Bird, 1M ( CNCI) ; The Pas , 14-Sept-51, W. Krivda, 1M ( CNCI) ; Winnipeg , 16- IX-09 , J.B. Wallis, 1M ( CNCI) ; NEW BRUNSWICK: Greys Mills , 15 IX 1922, R. P. Gorham, 1M ( CNCI) ; ONTARIO: Ottawa , 27.IX.12, 1M ( USNM) ; St. Lawrence Is. Nat. Park, Mulcaster Island , 5 XI 1976, W. Reid, Code 48294-50, 1M ( CNCI) ; Toronto , 1M ( BYUC) ; Ottawa , 8/IX/11, J.D. Tothill, 1M ( CNCI) ; Elgin Co., Springwater Con. Area , 20 Sept 1992, Coll. # 495, Ian Carmichael, 1M ( CNCI) ; Metcalfe , 29 IX 1984, B.E. Cooper, 1M ( CNCI) ; fen 5 mi. S. Richmond , 19–25 IX 1978, D.M. Wood, 1M ( CNCI) ; Merivale , 22 Sept 1951, R. Lambert, 1M ( CNCI) ; N. Burgess Twp., Lanark Co., 22 IX 1968, D.M. Wood, 1M ( CNCI) ; Lake Muskoka , 7 IX 1925, G.S. Walley, 1M ( CNCI) ; Maynooth , 5 IX 1953, J.F. McAlpine, 1M ( CNCI) ; SASKATCHEWAN: Moose Jaw , Dyar & Caudell, 2M ( USNM) ; 5 km E of Leask , YPT, 31.VIII.05, slough margin (freshwater), J. R. Vockeroth, 1M ( SFC) ; Indian Head , 19 IX 1928, K. Stewart, Rb-38- Cb, 50-III-321, 1M ( CNCI) ; Cecil , 6 IX 1977, F.J.H. Fredeen, 1M ( CNCI) ; Moose Jaw , 5 IX, N. Criddle, 1M ( CNCI) ; vi–viii 2005, J. R. Vockeroth, 2M ( CNCI) ; Estevan , 6 IX, N. Criddle, 1M ( CNCI) ; Swift Current , 17 IX 1940, A. R. Brooks, 1M ( CNCI) ; Hudson Bay , 15 IX 1959, J. R. Vockeroth, 1M ( CNCI) ; Regina , 5-Sept-03, 1M, 1F (in copula) ( CNCI) ; QUEBEC: St. Johns , 23.IX.05, 1M ( USNM) ; Lake Edward Camp, Laurnetide Limits , 15 IX 1948, 1M ( CNCI) ; Abbotsford , 7 IX, 1937, G.E. Shewell, 2M ( CNCI) ; Old Chelsea , 25 IX 1955, J. R. Vockeroth, 1M ( CNCI) ; Mt. Orford , 9 IX 1937, G.E. Shewell, 1M ( CNCI) ; Summit Rigaud Mtn. , 24 IX 1985, B.E. Cooper, 1M ( CNCI) ; Gatineau Park nr. Champlain Lkout. , 22 IX 1991, J.M. Cumming, ex. in copula, 1M, 1F ( CNCI) ; Laniel , 14 IX 1939, J.L. Hitchon, Exp No. 12128-15, 1M ( CNCI) ; Norway Bay , 30 VIII 1938, G.A. Hobbs, 1M ( CNCI) ; Beech Grove P.Q., 24 IX 1954, C.D. Miller, 2M ( CNCI) ; Masham Twp. , Gatineau Co., IX 1977, D.M. Wood, 2M ( CNCI) ; Lanoraie , 20- IX-80 , F. Liard, 2M ( CNCI) ; USA: COLORADO: Colorado Springs, Sept, 1M ( USNM) ; Boulder, Sept, S.A. Rohwer , 2M, 1F (1 pr. in copula) ( USNM) ; campus, Univ. of Colorado , Boulder, 1M ( USNM) ; “ Colo. ,” 2773, 1M ( CSUC) ; Larimer Co., Lory SP, Arthurs Rock Trail , 09 IX 1997, Burt, J.M., 1M ( CSUC) ; Masonville , 9/5/‘3[?], 1M ( CSUC) ; Masonville , 9 6 ‘34, M. T. James Col., 3M ( CSUC) ; Weld Co., 9-29’35, 1M ( CSUC) ; Larimer Co., 19 Sep 1992, Anderson’s Atlas, Upper Cherokee Park , Bjostad, 3M ( CSUC) ; Larimer Co., 18 Sept 1997, Res. dam, D. Leatherman, E. Hamilton, 2M ( CSUC) ; Larimer Co., Poudre River Rt. 14, Ansel Waltrous , 9 IX 1986, P. Kleintjas, 1M ( CSUC) ; Douglas Co., 28 Sept 1988, Malaise Trap over buried pig, B. Kondratieff, 1M ( CSUC) ; Larimer Co., 30 Sept. 1993, Phantom Canyon, S. Fitzgerald, 1M ( CSUC) ; Sedgwick Co., 17 Sept 1993, jct. US 385 & CR4, ex. ponderosa pine, D. Leatherman, 1M ( CSUC) ; CONNECTICUT: Stamford , 20 Oct 1935, 1M ( USNM) ; Stamford, B. T. R. Lab Col. , 15 Oct 1937, 1M ( USNM) , 27 Oct 1937, 1M ( USNM) ; Redding, A.L. Melander, Nov 30, 1M ( USNM) , 21 Oct ’28, 2M ( USNM) , 3 Oct 36, 1M ( USNM) , 13 Oct 35, 1M ( USNM) ; DISTRICT OF COLUMBIA: Washington D.C., Rock Creek Park, 28 Oct 1956, P.H. Arnaud Jr., 1M ( USNM) ; FLORIDA: Putnam Co., Univ. of FL Res., 26/ 27 Nov 1946, R. G. Bellamy, F.C. No. 2045, 1M ( CNCI) ; GEORGIA: Black Mt. , 11-2-46, P.W. Fattig, 1M ( USNM) ; IOWA: Ames , 1959, H.H. Knight, 1M ( USNM) ; KANSAS: Douglas Co., 900 ft., September, A.L. Melander, 1M ( USNM) ; MAINE: Hancock Co., 12 mi E Aurora , 28 IX 1984, D.M. Wood, 1M ( CNCI) ; MARYLAND: near Plummer I, 11. Oct. 21, H.S. Barber, 1M ( USNM) ; Patuxent Ref Bowie , 9-X-1944, Mitchell, 1M ( USNM) ; Hagerstown , 27-Sept-12, 1M ( USNM) ; nr. Plummers Id , 10.19.14, R. C. Shannon, 1M ( USNM) ; Plummers I, 5.X.12, J. R. Malloch, 3M ( USNM) ; Plummers Id , R. C. Shannon, 28.X.15, 1M ( USNM) , 10.X.14, 1M ( USNM); Bladensburg , 23.IX.15, R. C. Shannon, 5M ( USNM) ; Plummer’s Island , H.S. Barber, 30.10.07, 1M ( USNM) , 8.X.1902, 1M ( USNM) ; Largo , 10/16/58, 1M ( OSAC) ; MASSACHUSETTS: Southbridge, S.W. Bromley, Sept 19, 1M, 1F ( USNM) ; Amherst , 9 Oct 1923, 1M ( USNM) ; Middlesex Co., Lincoln, Malaise trap, E. T. Armstrong , 12–13 Oct 1982, 1M ( USNM) , 14 Oct 1982, 1F ( USNM) , 15 Oct 1982, 1M ( USNM) ; Hampshire Co., W. Chesterfield, 27 Sept. 1971, A.B. Gurney, 1M ( USNM) ; Beverly , 4-Oct-68, 2M ( USNM) ; Beverly, Burgess , 12.10.75, 1M ( USNM) , 8.10.75, 1M ( USNM); Cape Cod, Eastham , 20 IX 1992, J. R. Vockeroth, in Acer rubrum swamp, 1M ( CNCI) ; Mount Wachusett, Princeton , 13 Sept 1922, W. T. M. Forbes Coll., 1M ( BYUC) ; MICHIGAN: Livingston Co., E.S. George reserve , 7 Oct 1949, 185, K. Bohnsack, 2M ( USNM) ; E. Lansing, 5.X.1939, C. Sabrosky, 1M ( USNM) ; Luce Co., 8-30-52, R. R. Dreisbach, 1M ( USNM) ; Delta Co., 8-25-52, R. R. Dreisbach, 2M ( USNM) ; Ag. Coll. Mich. , 635, J.M. Aldrich, 1M ( USNM) ; Ag. Coll. Mich , 635, C.F. B., 2M ( CSUC) ; Ag. Coll. Mich , 421, C.F. B., 1M ( CSUC) ; MINNESOTA: St. Anthony Park , Lugger, 1M ( USNM) ; MISSISSIPPI: Lafayette Co., V–VI 1962, F.M. Hull, 1M ( CNCI) ; MISSOURI: Douglas Co., 2 Oct 2004, Hunter Cr., CRFF-210, SE Ava, B. Kondratieff, R. Zuellig, 1M ( CSUC) ; MONTANA: “ Mon. ,” 1M ( USNM); NEBRASKA : Dunbar, W.W. Wirth, 13.IX.50, 1M, 7F ( USNM); NEW JERSEY: Sussex Co., Coleville , 11 Oct 1970, J.W. Adams, 3M ( USNM) ; Dyckman St , 3-Oct-26, A.L. Melander, 1M ( USNM) ; Midland Park, hovering in apple orchard, E.A. Cohen Jr. , Oct 1995, 1M ( USNM) ; NEW YORK: Ithaca , 1M ( USNM) ; Greene Co., 2500 ft., L.O. Howard, 1M ( USNM) ; Hartsdale, G.P. Engelhardt , 9.X.1901, 1M ( USNM) , 8.X.1936, 1M ( USNM) ; Hamilton Co., 13 July 2009, Thayer Lake outlet, Shingle Shanty Research Stn, 43.95N, 74.75W, BLT, L. Myers, 1M ( CSUC) ; Essex Co., 15 Sept 2007, Small Stream, Rt 73 Nr. Round Pond, L. Myers, 1M ( CSUC) ; PENNSYLVANIA: Lehigh Gap , 5-X-03, 1M, 1F (in copula) ( USNM) ; Wilmerding, A.L. Melander, IX.13, 1M ( USNM) , IX.15, 1M, 1F ( USNM), IX.23, 2M ( USNM); SOUTH DAKOTA: “S.D.,” J.M. Aldrich coll., 12M, 1F ( USNM) ; Brookings , 3M ( USNM) ; TENNESSEE: Greene Co., 19 Oct 1985, Kondratieff, 2M ( CSUC) ; TEXAS: Travis Co., Austin, Brackenridge Field Lab , 170 m, 27 Oct 1992, C. R. Nelson #5872 & L, Bezark, 1M, 1F (in copula) ( BYUC) ; VERMONT: “Vt.,” 1M ( OSAC) ; VIRGINIA: Rosslyn , Oct 03, 1M ( USNM) ; Great Falls, Hopk US, C. T. Greene, Oct 22/15, 1M, 2F ( USNM) ; Chain Bridge , 1-Nov-16, C. T. Greene, 1M ( USNM) ; Lorton , 18-Nov-17, W.L. McAtee, 1M ( USNM) ; Falls Church , 17-Oct-15, J. Silver, 1M ( USNM) ; Great Falls , 11-Nov-17, W.L. McAtee, 1M ( USNM) ; Falls Church , 10.22.01, A.N. Caudell, 1M ( USNM) ; Fairfax Co., Springfield , 7402 Reservation Dr., by power line, 38°45.22’N, 77°16.13’W, 14 Oct 2013, R. C. Mower, 2M ( BYUC) ; Montgomery Co., 18 Oct 1983, Blacksburg, Kondratieff, 1M, 1F (in copula) ( CSUC) ; WEST VIRGINIA: Ash , 1M ( USNM) ; WISCONSIN: “ Wis. ,” Coquillett, 1M, 1F ( USNM) ; Marathon Co., 18- IX-36 , sweeping, H. R. Dodge, 1M ( USNM) ; Shawano Co., Cloverleaf Lks. , 16.IX.1938, H. R. Dodge, 4M ( USNM) ; Clintonville, H. R. Dodge, 12.IX.35, 1M ( USNM) , 17.IX.34, 1M, 1F ( USNM).

Diagnosis. Males of P. heteroptera are most easily distinguished from New World congeners by the relatively stout gonostylus with the apex minutely truncated or with a slight apical notch (often with a small point developed on the anterodorsal side of the notch) ( Figs. 16–20 ), tergite nine with posterior emargination usually relatively shallow (one-fifth to about one-third the length of the tergite) and broadly U-shaped, but sometimes deeper (up to 2/5) and more V-shaped, ventromedian lobes of gonocoxites weakly to moderately developed ( Fig. 20 , vml), posteromedian cleft of gonocoxites typically rather broad and shallow (somewhat isosceles trapezoidal in shape) ( Fig. 20 , vmc), and paramere dome-like, broadly rounded posteriorly, not diamond-shaped ( Figs. 16, 20 , 38 ).

Remarks. Previously, all “Nearctic” ( USA / Canada) specimens of Penthetria have been treated under the name P. heteroptera (e.g., Hardy 1945, 1965b, 1981). The present study recognizes three species of Penthetria in the USA and Canada: P. heteroptera (east of the Rocky Mountains in USA and Canada), P. arizonensis (southern Arizona, USA to Central America), and P. yakima (northwestern USA and sympatric with P. heteroptera throughout Canada).

In the USA and Canada, P. heteroptera is most similar to P. yakima from which males can be differentiated by the more robust gonostylus and less diamond-shaped paramere (compare Figs. 38–41 ). P. heteroptera appears to be allopatric and quite distinct from P. arizonensis within the USA; the former with gonostylus as described above and the later with apex of gonostylus broadly rounded or broadly rounded and culminating in an obtuse point ( Figs. 7–8 ). However, some Mexican and Central American specimens of P. arizonensis have the gonostylus slightly truncate and approximating the terminalia of some P. heteroptera specimens (see Remarks under P. arizonensis ).

Females of P. heteroptera ( Figs. 50–51 ) are indistinguishable from females of P. yakima ( Fig. 56 ); these two species are sympatric in Canada. However, females may be tentatively determined based on geographic distribution in the USA since, based on material examined, P. heteroptera is the only species known from the eastern USA.

Intraspecific Variation. P. heteroptera exhibits a level of intraspecific variation that can create confusion when making identifications. The intraspecific variation described below can sometimes be found even within a single series (same place/date) and therefore does not appear to be clinal (no correlation to geographic distribution) and does not appear to indicate the presence of a cryptic species complex. P. heteroptera males have 8–10 (usually 9) flagellomeres due to the subdivision of the normally more elongate basal or apical flagellomere (variation in number of antennal flagellomeres was found to vary in other Penthetria species as well). Male hind basitarsus relatively slender to robust to slightly swollen and sausage-shaped. The hind tibia ranges from thin and almost parallel-sided to very slightly clavate apically to distinctly clavate apically (the relative degree of swollenness in the tibia and hind basitarsus are correlated; those with more swollen tibia also have a more swollen hind basitarsus). As with many other species in the genus the venation is plastic. R 2+3 can vary up to 50% in length ( Figs. 21 a–21b) and cell cua may be closed or open. Wing length ranges from 5.5–8.0 mm (n=8) in males and 6.5–11.0 mm (n=5) in females. Females can have 8–10 (usually 9) antennal flagellomeres.

Geographic & Seasonal Distribution. Widespread in the southern Canadian Provinces (British Columbia to New Brunswick; one female Penthetria sp. studied from Nova Scotia) and east of the Rocky Mountains in the United States (Maine south to Florida and west to Colorado) ( Map 3 ). No definitive specimens (gonostylus with apical notch) have yet been studied from south of the USA though the species is known from Texas. Specimens also studied from Montana and Vermont, but not plotted on map due to insufficient label data. The species is also present in Germany ( Fitzgerald & Werner 2004) as result of an accidental introduction. See additional Nearctic records (not plotted on Map 3 ) in Appendix. Flight period July to November with the majority of records from September and October ( Table 1) .

Figures

FIGURE 1. P. heteroptera, habitus, male (above) and female (below), 28 October, North Carolina, USA, Matt Bertone. Images courtesy of Matt Bertone (© Matt Bertone 2013).

MAP 3. Distribution of P. heteroptera (black circle) and P. yakima (star).

FIGURES 16–20. P. heteroptera, male terminalia. 16. Dorsal, topotypic (Maryland, USA). 17. Gonostylus, dorsal (Texas, USA). 18. Gonostylus, ventral (Virginia, USA). 19. Gonostylus, dorsal (Vermont, USA). 20. Ventral, topotypic (Maryland, USA). Scale bar = ca. 0.5 mm. Abbreviations: dlp, divergent lobes of paramere; gc, gonocoxite; gs, gonostylus; p, paramere; t9, tergite nine; vmc, ventromedian cleft of gonocoxite; vml, ventromedian lobes of gonocoxite.

FIGURES 21–22. Penthetria and Plecia, wings, illustrating variation in length and slope of vein R 2+3. 21a–b. Penthetira heteroptera, males (both from Maryland, USA). 22a. Plecia dentata Hardy, male. 22b. Plecia biformis Hardy, male (points, x, y, z described in “Discussion supporting generic diagnosis”). Scale bars = ca. 1.0 mm.

FIGURES 38–41. Male terminalia. 38. P. heteroptera, dorsal, tergite nine removed, topotypic (Maryland, USA). 39. P. yakima n. sp., holotype, dorsal, tergite nine removed. 40. P. heteroptera, posterior, topotypic (Maryland, USA). 41. P. yakima n. sp., holotype, posterior. Scale bar = ca. 0.5 mm.Abbreviations: c, cerci; ea, ejaculatory apodeme; ga, gonocoxal apodeme; gc, gonocoxite; gs, gonostylus; p, paramere; t9, tergite nine.

FIGURES 50–53. Female terminalia. 50. P. heteroptera, dorsal. 51. P. heteroptera, ventral. 52. P. arizonensis n. sp., ventral. 53. P. arizonensis n. sp., lateral. Scale bars = ca. 0.25 mm. Abbreviations: c1, cercus 1; c2, cercus 2; gf, genital fork; s7, sternite seven; s8, sternite eight; s10, sternite ten; sp, spermatheca; t7, tergite seven; t8, tergite eight; t9, tergite nine.

FIGURES 54–57. Female terminalia and eggs. 54–56. Female terminalia. 54. P. neonigrita n. sp., dorsal. 55. P. neonigrita n. sp., ventral. 56. P. yakima n. sp., ventral. 57. P. heteroptera, eggs (dissected from abdomen). Scale bars = ca. 0.25 mm. Abbreviations: c1, cercus 1; c2, cercus 2; s7, sternite seven; s8, sternite eight; s10, sternite ten; sp, spermatheca; t7, tergite seven; t8, tergite eight; t9, tergite nine.

FIGURES 7–8. P. arizonensis n. sp., holotype, male terminalia. 7. Dorsal. 8. Ventral. Scale bar = ca. 0.5 mm. Abbreviations: dlp, divergent lobes of paramere; gc, gonocoxite; gs, gonostylus; p, paramere; t9, tergite nine.