Penthetria appendicula Hardy 1945
Creators: name: Fitzgerald, Scott J.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Bibionidae
Penthetria
Penthetria appendicula

description: Penthetria appendicula Hardy, 1945
(Figs. 2–6, 44, 46–47, Map 1)
Type Material. Holotype male (not examined): COSTA RICA: Volcan Poas, 21 April 1916, A. Alfaro (USNM). Paratypes (examined): COSTA RICA: CARTAGO: San Cristobal, 5400 ft., 27 Mar ’28, F.G. Wallace, 1M (USNM); “La Carpentera” [=La Carpintera?], April, W.M. Mann, 1M (USNM); “La Carpentera” [=La Carpintera?], April 1924, H.W. Atkinson, 1F (allotype) (USNM).
Material examined. COSTA RICA: El Volcan Trazee, 3080 m, 9.IX.43, P. Knight, 3M (USNM); CARTAGO: S Cerro La Muerte, 3000 m, 11.VIII.90, J. Powell, 1M (SFC); S. border, Pension La Georgina, 3000 m, Cerro de Muerte, 23–25 May 1985, J. Powell, 8M, 2F (EMEC); Catie, 3 km SE Turrialba, 600 m, 13–16 May 1985, J. Doyen, 1M (EMEC); Rio Aquiares, nr. Santa Cruz, 1500 m, 9 km NW Turrialba, 15 May 1985, J. Doyen, 1M (EMEC); HEREDIA: #6 Heredia, Vota Steinvorth Finca S. slope V. Barba, 2100 m, 8 Feb. 1965, J.B. Karren, 4M (NHMLA); Est. Barra P.N. Braulio Carrillo, Oct. 1989, 2500 m, G. Rivera, L-N-233400, 523200, 18M, 2F (INBC); Est Barra, P.N. Braulio Carrillo, July 1990, 2500 m, B. Apu & G. Varela, L-N-23200, 523100, 2M (INBC); SAN JOSÉ: Volcan Poas, 9–10.VII.63, C.L. Hogue, 1M (NHMLA); Poas N.P., 5 Feb. 1987, G.E. Bohart, 3M, 1F (NHMLA); S. Gerardo de Dota, 9°33’N, 83°48’W, 2200 m, 1M, 1F (in copula) (CNCI); Cascajal de Coronado, Bajo La Rosa, 3-V-1995, Baumann & Houseman, 6M, 9F (1 pair in copula) (BYUC); Nubes de Coronado, La Abigail, 5-V-1995, Baumann & Houseman, 11M, 7F (BYUC), 1M, 1F (in copula) (SFC); Nubes de Coronado, Rio Virilla, 6-V-1995, R. W. Baumann & R. M. Houseman, 1M (BYUC); 6 March 1967, E.B. Fagan, 1M, 1F (FSCA); La Cima de Dota, 2300 m, 14 May 1993, M. Chavarria, LS183500-548300 # 2154, 4M, 3F (INBC); MEXICO: MEXICO: 22 August 1994, Arroy at El Capulin, B. Kondratieff, R. Baumann, 1M (CSUC); CHIAPAS: Mt. Tzontehuitz, 9400’, 12 mi NE San Cristobal, B. V. Peterson, 19 V 1969, 3M, 1F (CNCI), 1M, 1F (SFC); Mt. Tzontehuitz, 9400’, 12 mi NE San Cristobal, B. V. Peterson, 27 V 1969, 11M (CNCI); 9500’, Mt. Tzontehuitz, 27 V 1969, H.J. Teskey, 2M (CNCI); Mt. Zontehuitz, 9500’, 27 V 1969, Malaise trap, B. V. Peterson, 1M, 1F (CNCI).
Diagnosis. Males of P. appendicula can be distinguished from all New World congeners by the following combination of characters: tergite nine with posteromedial emargination deep (about two-thirds the length of the tergite) with a field of densely-set, short, black, spine-like setae on the posteroventral edge, which contrast the typical setae on the remainder of the tergite (Figs. 4–5), posterior, inner (ventral) surface of ninth tergite not developed (or at most only very weakly developed) into a pair of broad flat shelves when viewed posteriorly (Fig. 5), gonostylus shining, basally with long hairs, but more distally with only very minute and spare hairs, slender and apically coming to a narrowly rounded point (Fig. 5), ventromedial lobes of gonocoxite absent to very weakly developed, and R 2+3 often with a basal appendix (Fig. 2, ba).
Remarks. P. appendicula is a fairly large species with male wing 7.0–10.0 mm (n=5) and female wing 9.0–11.0 mm (n=2) and is most similar to P. distincta. Males of these two species share the tergite nine deeply emarginate posteromedially with a field of densely-set, short, black, spine-like setae on the posteroventral edge, which contrast typical setae on the remainder of the tergite, gonostylus shining, basally with long hairs, but more distally with only very minute and sparse hairs, and the tendency to have a basal appendix on R 2+3. Additionally, in dorsal view, both species have the paramere robust and dome-like, with the dorsal surface slightly laterally-compressed into a ridge and posteriorly with a slight nubbin at the apex (Figs. 42 & 44, p), though there is a pair of divergent lobes (whaletail-like structure) on the ventral subapical surface of the paramere, which can appear apical if the orientation of the paramere is tipped slightly (e.g., it can barely be seen in Fig. 44, dlp). The shared similarities of P. appendicula and P. distincta suggest they are more related to each other than to other New World species (see additional information on female characters below).
Females of P. appendicula and P. distincta can be differentiated from all New World congeners by the more elongate ultimate segment of the cerci, the more slender posteromedian lobes of sternite eight (Figs. 46–48), and the tendency to have an appendix at the base of R 2+3 (Fig. 2, ba). Differences between females of P. appendicula and P. distincta are minor and, at present, not enough females (associated with males) of the two species have been studied to ensure that the few character state differences found are consistent. From material studied, sternite ten is tapered posteriorly to a rounded point in P. appendicula (Fig. 47, s 10) versus not tapered and more truncate/broadly rounded posteriorly in P. distincta (as in Fig. 49, s 10; s10 not visible in Fig. 48 due to segments partially telescoped within preceding segments). However, females of P. neonigrita have sternite 10 variable (ranging from broad to more tapered posteriorly), so this character may not be useful in distinguishing species. Both P. appendicula and P. distincta have tergite nine medially divided, but it is more broadly represented dorsolaterally in P. appendicula and more strap-like in P. distincta.
Geographic & Seasonal Distribution. Mexico and Costa Rica (Map 1); additional Costa Rican records in Hardy (1945). Seasonal distribution summarized in Table 1.
description: Published as part of Fitzgerald, Scott J., 2021, Penthetria Meigen (Diptera: Bibionidae): Revision of the New World species and world catalog, pp. 451-500 in Zootaxa 4926 (4) on pages 461-463, DOI: 10.11646/zootaxa.4926.4.1, http://zenodo.org/record/4529512