Myzinum cocoritensis Kimsey

Kimsey, Lynn S., 2009, Taxonomic purgatory: Sorting out the wasp genus Myzinum Latreille in North America (Hymenoptera, Tiphiidae, Myzininae), Zootaxa 2224, pp. 30-50 : 40

Myzinum cocoritensis Kimsey , new species

Figs. 1 , 3, 4, 7, 9, 12, 14

Male.―Body length 7–13 mm. Head: hypostomal fossa broader than long; clypeus apicomedially bilobate; hypostomal angle obtuse in side view ( Fig. 1 ); ocellocular distance 0.6x interocellar distance; frons punctures; mandible with small subsidiary tooth; flagellomere I length 1.2x breadth; flagellomere XI length 1.7–1.8x breadth. Thorax: without omaulus; metapleuron polished, impunctate medially; propodeal punctures contiguous, arranged in transverse rows posteriorly; hindcoxa with obtuse sharp ventromedial tooth; hindfemur with short ventral carina submedially forming obtuse angle or tooth in side view. Metasoma: tergum I strongly convex, without lateral grooves or carinae; epipygium subapically elongate and narrowed, with shallow apical notch, apical teeth blunt. Genital capsule (Figs. 7, 14): paramere ventral lobe broadest medially, spines broad, peg-like, on apical three-fourths of lobe, narrowly notched between dorsal and ventral lobes, dorsal lobe broadly obtuse, with 4–5 short setae; volsellar shape triangular viewed laterally, axis twisted 90°, apical setae short, digitus apical lobe narrow, elongate with row of peg-like spines (not setae as in other Myzinum ); aedeagus strongly narrowed apically, apical bulb narrower than shaft base. Color: black to dark brown, with pale yellow to yellow markings; clypeus with medial yellow spot, mandible yellow with red apex; pronotum with yellow stripe along posterior margin, with oblique anterolateral yellow branch; parategula and tegula with yellow spot; forewing basal veins yellow; mesopleuron with small dorsal spot below wing fossa; scutum, scutellum and metanotum with medial yellow spot; femora yellow apically; tibial outer surface yellow; tarsi yellow to orange; metasomal terga I–VI with irregular transverse posterior stripe, sterna I–VI with small lateral yellow spot. Ves ti tu re: long, erect, silvery, particularly apparent on head.

Female.―Body length 11 mm. Head: hypostomal fossa as long as broad; hypostomal angle obtuse in side view. Thorax: pronotum laterally with coarse parallel ridges, dorsal surface polished, pronotum, scutum and scutellum punctures 1–3 PD apart; metapleuron and propodeal lateral surface with strong parallel horizontal ridges; propodeum with transverse ridges or wrinkles; forewing R1 vein obsolescent. Metasoma: terga and sterna finely, minutely shagreened, punctures 1–3 PD apart. Color: dark brown to black, with pale yellow marks; mandible base dark red, apex black; pronotum with anterolateral yellow spot; scutum with posteromedial yellow spot; metanotum yellow medially; tergum I with posterolateral spot; tergum II–V with irregular posterior stripe; sternum II–V with small lateral spot. Vestiture.―long, silvery.

Holotype male.― MEXICO: Sonora, Cocorit, 28 May 1962, F. D. Parker & L. A. Stange. Paratypes: 354 males, 1 female; 224 males, same data as holotype; 150 males, same data as holotype, except 11 June 1961, F. D. Parker; 1 female, same data as holotype, except 29 June 1963.

Etymology.―The species is named after the collection site of the holotype, Cocorit, Mexico.

Discussion.―This is an oddly modified, atypical species of Myzinum . It has so many highly derived features that it may ultimately deserve its own genus. Features that distinguish it from other Myzinum species include modifications of the head, male hindleg, female forewing, male first metasomal segment and the male genitalia. Unlike other Myzinum species the hypostomal bridge in cocoritensis is broadly obtuse in lateral view in both sexes, not forming a right or subacute angle. The male hindleg has a tooth on the ventral surface of the femur and side of the coxa. The female forewing lacks a R1 vein on the costal margin of the marginal cell. The male first metasomal segment is globular and lacks the basolateral indentations typical of other species. Male genitalic modifications are also unusual, with the paramere ventral lobe and volsella appearing twisted in side view.

This species appears to have the most limited distribution of any in the genus Myzinum . The type specimens were all collected in the early 1960’s, in the vicinity of Tucson and Cocorit. Both of these cities have seen enormous growth in the past decades and it may very well be that cocoritensis is now extinct. It would be well worth looking at likely habitats in the vicinity of both cities and in the intervening territory.

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.