Myzinum dubiosum (Cresson)

Kimsey, Lynn S., 2009, Taxonomic purgatory: Sorting out the wasp genus Myzinum Latreille in North America (Hymenoptera, Tiphiidae, Myzininae), Zootaxa 2224, pp. 30-50 : 41-42

Myzinum dubiosum (Cresson)

Fig. 2 , 16 ; Map 2

Myzine dubiosa Cresson 1872:200 . Holotype female; USA: Texas (PHILADELPHIA).

Myzine texana Cresson 1872:200 . Holotype female; USA: Texas, Comal Co. (PHILADELPHIA). Synonymized by Krombein 1938.

Plesia fulvinervis Cameron 1908:239 . Holotype female; USA: Colorado, Berkeley Co. (LONDON). Synonymized by Krombein 1938.

Male.―Body length 10–15 mm. Head: frons punctures contiguous to 1 PD apart; flagellomere I twice as long as broad; hypostomal angle 90° in side view; ocellocular distance as long as interocellar distance; flagellomere I length 1.8x breadth; flagellomere XI length twice breadth. Thorax: mesopleuron with omaulus, punctures 2–5 PD apart; propodeum densely, but finely punctate; forecoxa and midtrochanter unmodified; hindcoxa with short, small, tooth-like carina on inner margin. Metasoma: tergum VII flattened and polished apicomedially, laterally carinate along edge of apical tooth. Genital capsule ( Fig. 16 ): paramere ventral lobe as broad as dorsal lobe, 2.6–3.0x as broad as long, spines extending along half lobe length, dorsal lobe marginal setae fewer than six, less than half as long as volsella; volsella subtriangular, triangular in cross-section, setose apically, half as long as paramere ventral lobe; aedeagus apical bulb 2.0–2.5x as broad as shaft below. Color: black, with yellow markings; clypeus yellow, inner eye margin with yellow band, antennal lobe with yellow spot, mandible apically and medially yellow, scape largely yellow; pedicel and flagellum dark brown; pronotum with broad, transverse yellow band across anterior and posterior margins; scutum, scutellum, metanotum with large yellow medial spot, scutum sometimes with lateral yellow spot; mesopleuron with large anterior and posterior yellow spots; propodeum with large, sublateral yellow spot; coxae with dorsal yellow spot; femora apically yellow, tibiae mostly yellow, with some brown ventrally; tarsi yellow; wing membrane slightly brown-tinted, veins light brown to yellowish; metasomal terga I–VI with transverse posterior yellow band; sterna II–VI with lateral yellow spot. Ve st it u re: silvery.

Female.―Body length 10–13 mm. Head: frons punctures somewhat striatiform, contiguous near antennal lobes, becoming sparser near midocellus; interocellar distance 0.8x ocellocular distance; vertex punctures 1–3 PD apart; hypostomal angle acute in lateral view; flagellomere I length 0.8x breadth. Thorax: pronotum dorsal surface without tiny interpunctures between punctures, except in band across anterior margin; propodeum laterally smooth to finely transversely striate, posterior surface with a few large transverse ridges otherwise smooth; forebasitarsis with six rake spines. Color: black, with yellow and red markings; head with yellow band along inner and posterior eye margin and across antennal lobes; scape, pedicel and flagellum reddish brown, clypeus and mandible reddish brown to brown; pronotum with broad transverse anterior yellow band, sometimes broken medially, sometimes with yellow on posterior margin; mesopleuron with large anterior and posterior yellow spots; scutum with medial and posterolateral yellow spots; scutellum and metanotum with medial yellow spot; propodeum with large yellow sublateral spot; femora red, with ventral yellow spot; foretibia with large dorsal yellow spot; rest of legs reddish brown; metasomal tergum I reddish brown, with large dorsal yellow spot reaching posterior margin; terga II–VI brown, with broad, yellow, transverse band; sterna II–IV brown, with sublateral and sometimes posterolateral yellow spots; segment VI dark brown; wing membrane lightly brown-tinted becoming darker apically, veins reddish brown. Vestiture: silvery.

Distribution (Map 2).― USA: Arizona: Cochise, Graham, Maricopa, Mohave, Navajo , Pima, Pinal, Santa Cruz, Yavapai, Yuma Counties; California: Imperial, Kern, Riverside, San Bernardino Counties; Colorado: Adams, Berkeley Counties; Florida: Alachua Co.; Kansas: Riley Co.; New Mexico: Bernatillo, Dona Ana, Eddy, Hidalgo, Lincoln, Otero, San Juan, Socorro, Valencia Counties.; Texas: Brewster, Comal, Hudspeth, Lavaca, San Patricio Counties; Utah: Cache Co.; MEXICO: Baja California, Guerrero, Sonora; 124 females and 350 males were studied.

Discussion.―This is one of the smaller bodied species of Myzinum . Male dubiosum are easy to distinguish from those of other species, as they have a tiny tooth or angle on the inner margin of the hindcoxa. In addition, the paramere ventral lobe is half the breadth of the paramere in side view and the volsella is triangular in cross-section. Females on the other hand are more difficult to distinguish. They closely resemble female frontalis and the two species are often found in the same localities. Females can be distinguished by the bicolored wings (untinted in frontalis ), pronotum with interpunctures medially across the anterior margin (lacking in frontalis ) and the ocellocular distance at most 1.5x interocellar distance (broader in frontalis ).

Figures

FIGURES 1, 2. Female head, side view. 3, 6. Male wings. 4, 5. Male hindcoxa, trochanter and femur, side view. 7, 8. Male genital capsule inner surface. Abbreviations: ae = aedeagus, c = cuspis, d = digitus, p = ventral lobe of paramere. 9. Male metasomal segment I, lateral and dorsal views. 10 – 12. Male epipygium, dorsal view.

FIGURES 13 – 22. Male genital capsule, lateral view. Abbreviations: ae = aedeagus, dl = paramere dorsal lobe pa = paramere, v = volsella; vl = paramere ventral lobe.