Myzinum

Kimsey, Lynn S., 2009, Taxonomic purgatory: Sorting out the wasp genus Myzinum Latreille in North America (Hymenoptera, Tiphiidae, Myzininae), Zootaxa 2224, pp. 30-50 : 33-34

Key to the North American species of Myzinum

1 Metasoma with 7 visible segments, apical sternum forming slender hook (uncus); antenna 13-segmented, usually held straight, not coiled; body long slender; males....................................................................................................... 2

- Metasoma with 6 visible segments, apical sternum not slender or hook-like; antenna 12-segmented, usually coiled; body robust; females ................................................................................................................................................... 10

2 Forewing marginal cell Rs vein obsolescent or indicated by stained line (Fig. 3); hypostomal angle obtuse in side view; paramere ventral lobe with 3–4 peg-like spines apically (Fig. 7) .................. cocoritensis Kimsey, new species

- Forewing marginal cell Rs vein present (Fig. 6); hypostomal angle forming right or acute angle in side view; paramere ventral lobe with slender spines apically (as in Fig. 8)................................................................................. 3

3 Metasomal tergum VII with medial longitudinal groove or crease (as in Fig. 11).......................................................4

- Metasomal tergum VII flat, without medial longitudinal groove or crease.................................................................. 5

4 Wing membrane evenly brownish yellow; tergum VII usually marked with yellow; volsella flat, apically rounded ... ............................................................................................................................................ quinquecinctum (Fabricius)

- Wing membrane largely hyaline, darkened at tip; tergum VII black, without yellow; volsella triangular in cross-sec- tion, pointed apically .......................................................................................................................carolinanum Panzer

5 Midcoxa dentate, lobate or broadly angulate on inner margin (as in Fig. 5)................................................................ 6

- Midcoxa unmodified..................................................................................................................................................... 7

6 Midcoxa lobate or dentate (Fig. 5); paramere ventral lobe less than 3x as long as broad basally, margin above notch angulate, ventral lobe having spines along apical fourth of length ( Fig. 21 ) ............................... obscurum (Fabricius)

- Midcoxa broadly angulate; paramere 3.5x or greater as long as broad basally, margin above notch linear, ventral lobe having spines along three-fourths of length ( Fig. 17 ) .......................................................................... frontalis Cresson

7 Hindcoxa with small, low tooth on inner margin; paramere ventral lobe with spines extending along more than half length; volsella triangular in cross-section ( Fig. 16 ) ....................................................................... dubiosum (Cresson)

- Hindcoxa without small tooth on inner margin; paramere with ventral lobe spines extending along one-third length or less; volsella various ................................................................................................................................................. 8

8 Paramere medial notch absent, ventral lobe undeveloped, not distinguished from dorsal lobe; volsella as long or nearly as long as paramere ventral lobe (as in Fig. 19 ); aedeagus not apically bulbous, narrowly enlarged apically, with ventral ridge narrow, not lamellate ....................................................................................................................... 9

- Paramere medial notch deep, clearly separating ventral from dorsal lobe; volsella one-third to one-half as long as paramere ventral lobe; aedeagus apically bulbous, greatly inflated, more than twice as broad as shaft below, ventral ridge broadly lamellate ( Fig. 20 ) ......................................................................................................... navajo Krombein

9 Flagellomere I 1.4–1.6x as long as broad; volsella triangular in cross-section. ......................... maculatum (Fabricius)

- Flagellomere I 1.2–1.3x as long as broad; volsella flat in cross-section ........................................ confluens (Cresson)

10 Forewing marginal cell Rs vein obsolescent or indicated by stained line; hypostomal angle obtuse in side view ( Fig. 1 ) ............................................................................................................................... cocoritensis Kimsey, new species

- Forewing marginal cell Rs vein present (as in Fig. 6); hypostomal angle forming right angle or acute angle in side view (as in Fig. 2 ) ....................................................................................................................................................... 11

11 Propodeal side smooth, without striae or ridging ....................................................................... carolinianum (Panzer)

- Proodeal side longitudinally or obliquely striate or ridged......................................................................................... 12

12 Pronotal disk with numerous tiny punctures between larger ones across most of surface, accompanied by short bristle-like orange or yellow setae ........................................................................................................ fulviceps ( Cameron)

- Pronotal disk without numerous tiny punctures between larger ones or only a few tiny ones anteriorly, with scattered pale or black setae ....................................................................................................................................................... 13

13 Propodeum posteriorly entirely covered with coarse ridges radiating out from petiolar socket ....... navajo Krombein

- Propodeum posteriorly smooth or with weak radiating striae .................................................................................... 14

14 Scutum and scutellum entirely black, without yellow markings; metasomal terga with lateral yellowish, ovoid spots not bands ....................................................................................................................................... obscurum (Fabricius)

- Scutum and scutellum black with yellow markings; one or more metasomal terga with complete or medially broken yellow band ................................................................................................................................................................. 15

15 Antenna pale red; wing membrane yellowish brown; pronotal disk with anterolateral yellow spot and broad posterior band; ocellocular distance about twice as long as interocellar distance; body length 18–22 mm ........................... ............................................................................................................................................ quinquecinctum (Fabricius)

- Antenna brownish red to black; wing membrane untinted; bicolored or infuscate; pronotal disk coloration variable; ocellocular distance usually less than twice as long as interocellar distance; body length less than 18 mm ............. 16

16 Forewing with costal margin dark, infumate, rest of wing untinted; pronotal disk beyond anterior margin at least partly bipunctate unless punctures confluent .............................................................................. maculatum (Fabricius)

- Forewing entirely hyaline or uniformly infuscate; pronotal disk usually not bipunctate beyond anterior margin .... 17

17 Metasomal terga I–V with anterior and posterior transverse yellow bands ................................... confluens (Cresson)

- Metasomal terga I–V only with anterior transverse yellow band or lateral spots ...................................................... 18

18 Wings hyaline ...................................................................................................................................... frontalis Cresson

- Wings brown-tinted, at least along costal margin .............................................................................. dubiosum Cresson

Figures

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

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.