Nixonia stygica, Johnson & Masner, 2006

Johnson, Norman F. & Masner, Lubomír, 2006, Revision of World Species of the Genus Nixonia Masner (Hymenoptera: Platygastroidea, Scelionidae), American Museum Novitates 3518 (1), pp. 1-32 : 26-29

Nixonia stygica , new species

Figures 64–67

DESCRIPTION: Holotype female. Length: 4.8 mm; body generally black; femora, tibiae, tarsi, antenna, tegula black; palpi brown; wings infuscate throughout, brownish.

Head (figs. 64–66) transverse in dorsal view, width 1.9 times length; vertex rugulose-punctate, shining; lateral ocellus contiguous with inner orbit; POL 1.1 times LOL; occiput rugulose-punctate, shining; occipital carina present medially as low, crenulate carina; frons (fig. 65) rugulose-punctate, shining, above toruli with dense transverse wrinkles; frons narrow, IOS 0.7 times greatest length of eye; toruli separated by distance subequal to diameter of torulus, frons between toruli not projecting, flat; rim of torulus raised dorsally, laterally; apical margin of clypeus broadly convex; area below eye (in normal position of malar sulcus) with fine granulate microsculpture; cheeks laterad of malar area rugosepunctate, with distinct longitudinal sculpture; mandible short, bidentate, upper tooth only slightly longer than lower, without dense basal tuft of setae; maxillary palpal segment 4 distinctly expanded medially, subtriangular; A1 finely reticulate, greatest width at midpoint of segment; length of A3 1.8 times length of A2.

Mesosoma (figs. 64, 66) as high as wide, length 1.4 times height in lateral view; pronotal shoulders coarsely punctate; lateral surface of pronotum with fine longitudinal rugulosity; netrion punctate-rugulose, with strong longitudinal sculpture; mesoscutum: deeply punctate, with fine reticulate microsculpture; parapsidal lines absent; scutellum coarsely punctate, with reticulate microsculpture, without longitudinal sculpture; median propodeal tooth triangular, narrow, length 1.6 times maximum width, rounded apically, longitudinally carinate; upper mesepisternum with strong longitudinal sculpture; fine foveae separating mesepisternum and mesepimeron extending from base of wing to coxal cavity; lower mesepisternum finely reticulate-punctate; mesepimeral hook largely smooth, with few longitudinal keels; tegula finely punctate; apex of R 1 in forewing reaching costal margin; apex of forewing extending to midpoint of T5; R in hindwing with tracheate section short, broadly separated from hamuli by distance greater than its length; tibiae with fine, semidecumbent spines on outer surface.

Metasoma (fig. 67) 3.2 times longer than greatest width; T1 distinctly wider than long; terga longitudinally rugose; female T6 moderately large apical emargination, width greater than depth, anteromedially with field of granulate microsculpture.

Additional character from male: tyloids present on A4, A5.

DIAGNOSIS: This very dark species is most similar to N. corrugata . It may be distinguished by its black body and the more elongate forewing, extending nearly to the apex of T5.

ETYMOLOGY: Named after the River Styx, dark river of Hades, in reference to the overall color of the animal.

MATERIAL EXAMINED: Holotype female. SOUTH AFRICA: Eastern Cape Province, 43 km NE Willowmore , 33 ° 08.31 9 S 23 ° 50.48 9 E, 18.XI–22.XI.1999, M. E. Irwin et al., OSUC 146451 . Deposited in SANC . Paratypes: SOUTH AFRICA: Western Cape Province, 23 km N Oudstshoorn , 33 ° 25 9 28 0 S 22 ° 14 9 42 0 E, 500 m, 1–23.X.2004, M. E. Irwin, F. D. Parker, M. Hauser, malaise trap in wash, SA-11, OSUC 168997 , 1 female . Western Cape Province, 30 km NE Barrydale , 33 ° 14 9 49 0 S 20 ° 57 9 34 0 E, 440 m, 1– 22.X.2004, malaise trap in woodland wash, OSUC 168998 , 1 female . Western Cape Province, 18 km S Sutherland , 32 ° 32 9 16 0 S 20 ° 37 9 09 0 E, 1390 m, 3–24.X.2005, M. E. Irwin, F. D. Parker, M. Hauser, malaise trap, SA 19, OSUC 168999 , 169000 , 1 male, 1 female . Deposited in INHS, CNCI .

Nixonia watshami , new species

Figures 9, 13 , 68–73

DESCRIPTION: Holotype female. Length:

5.5 mm; body generally black; femora, tibiae,

tarsi reddish brown; A1–A2, tegula brown; palpi light brown; wings partially infuscate, brownish.

Head (figs. 13, 68–70) moderately transverse in dorsal view, width 1.4 times length; vertex rugulose-punctate, shining; OOL short, lateral ocellus separated from inner orbit by less than one ocellar diameter; POL 1.6 times LOL; occiput rugulose-punctate, shining; occipital carina not developed; frons (fig. 69) rugulose-punctate, above toruli with dense transverse wrinkles; frons broad, IOS 1.1 times greatest length of eye; toruli separated by distance of approximately one-half diameter of torulus, frons between toruli not projecting anteriorly; rim of torulus evenly raised; apical margin of clypeus with blunt medial projection; area below eye (in normal position of malar sulcus) with fine granular microsculpture, distinct from surrounding area; sculpture of cheeks laterad of malar region with slight longitudinal orientation; mandible moderately long, bidentate, upper tooth only slightly longer than lower tooth, without dense basal tuft of setae; maxillary palpal segment 4 distinctly expanded, subtriangular (figs. 9, 73); A1 finely reticulate, greatest width in apical two-thirds of segment; length of A3 1.8 times length of A2.

Mesosoma (figs. 68, 70) as high as wide, length 1.3 times height in lateral view; pronotal shoulders rugose-punctate; lateral surface of pronotum with fine longitudinal rugulosity; netrion with weak longitudinal sculpture, deep punctures; mesoscutum rugose-punctate, without transverse elements in sculpture, shining; parapsidal lines absent; scutellum rugose-punctate, sculpture with fine longitudinal elements in posterior half; medial propodeal tooth strong, slightly longer than wide, rugulose, with slight emargination posteriorly; upper mesepisternum with strong longitudinal sculpture; fine foveolae separating mesepisternum and mesepimeron present in upper half of sclerite, absent below; lower mesepisternum finely reticulate-punctate; mesepimeral hook longitudinally keeled; tegula with granular microsculpture; apex of R 1 in forewing touching costal margin; apex of forewing slightly surpassing apex of T4; R in hindwing with tracheate section long, nearly reaching hamuli; tibiae with only fine, semidecumbent spines on outer surface.

Metasoma (fig. 71) 2.9 times longer than greatest width; T1 distinctly wider than long; all terga longitudinally rugose; T6 with moderately large emargination medially, width of emargination greater than depth; base of T6 with anteromedial field of granulate microsculpture.

DIAGNOSIS: This is a rather small and unremarkable species of Nixonia . It seems to be most similar to N. pretiosa and may be distinguished by its uniformly dark color.

BIOLOGY: Egg parasitoid of Acanthoplus discoidalis (Walker) ( Orthoptera : Tettigoniidae , Hetrodinae ).

ETYMOLOGY: Named in honor of Anthony Watsham, wonderful friend and great naturalist, who has dedicated his life to Zimbabwe.

MATERIAL EXAMINED: Holotype female, BOTSWANA: Serowe , Farmer’s Brigade,

III.1992, P. Forchammer, malaise trap, OSUC 146414 , deposited in CNCI. Paratypes : BOTSWANA: Central Dist. , Serowe , II.1990, P. Forchhammer, malaise trap, 1 male, CASENT 2042613 ; III.1990, 2 males, CASENT 2042615 , CASENT 2042614 ; IV.1990, 2 males, CASENT 2042617 , CA- SENT 2042616; V.1990, 1 male, CASENT 2042612 . Serowe , Farmer’s Brigade , II.1989, P. Forchhammer, malaise trap, 1 male, OSUC 149459 ; III.1986, malaise trap, 1 female, OSUC 146413 ; III.1989, malaise trap, 1 male, OSUC 149449 ; III.1993, malaise trap, 2 males, OSUC 146417 , OSUC 146418 ; IV.1986, malaise trap, 1 male, OSUC 146416 ; 5–8.V.1994, malaise trap, 1 male, OSUC 146415 ; V.1987, 1 female, OSUC 146412 ; V.1989, malaise trap, 17 males, 1 female OSUC 149431 , OSUC 149432 , OSUC 149433 , OSUC 149434 , OSUC 149435 , OSUC 149436 , OSUC 149437 , OSUC 149438 , OSUC 149439 , OSUC 149440 , OSUC 149441 , OSUC 149442 , OSUC 149443 , OSUC 149444 , OSUC 149445 , OSUC 149446 , OSUC 149447 , OSUC 149448 ; VI.1988, malaise trap, 3 males, OSUC 149451 , OSUC 149452 , OSUC 149453 ; VII.1988, malaise trap, 4 males, OSUC 149454 , OSUC 149455 , OSUC 149456 , OSUC 149457 ; X.1988, malaise trap, 1 male, OSUC 149458 . No locality data, reared ex eggs of Acanthoplus discoidalis , C 805, 2 males, 2 females, OSUC 149820 , OSUC 149821 , OSUC 149822 , OSUC 149823 . NAMIBIA: Ovambo , Omusati, 1997 (probably IV–VI.1997), from eggs of bush cricket Acanthoplus discoidalis , wasp emerged V.2000, 1 female, OSUC 146456 . Gobabis, Farm Vendetta 202, Swart Nossob R., 21 ° 55 9 S 18 ° 11 9 E , 26–28.XI.1996, M. E. Irwin, E. I. Schlinger, E. Marais, malaise trap, 1 female, OSUC 146457 . ZIMBABWE: Harare [recorded as Salisbury ], IV.1982, A. Watsham, 1 male, OSUC 146452 ; V.1982, 2 males, OSUC 146453 , OSUC 146454 . Deposited in CASC, CNCI, OSUC, SANC, UCDC, USNM .

COMMENTS: Armored bush crickets are pests of millet and sorghum in southern Africa (www.icrisat.org/satrends/01aug/1.htm). In this area of erratic rainfall, it is normal for some of the eggs to hatch not in the season immediately following oviposition, but one year later. Apparently, this is also true of its egg parasitoid. S. V. Green (personal commun.) reported ‘‘...the Acanthoplus eggs had lain dormant [in the laboratory] for several years, then I incubated them under moist conditions and had some hatching of Acanthoplus (no parasitoids detected at that time). Then I reincubated the unhatched Acanthoplus eggs a year later and this time got the single Nixonia , but no armored bush crickets.’’

Figures

Figs. 64–67. Nixonia stygica, n.sp., holotype female (OSUC 146451). 64. Lateral habitus. 65. Head, frontal view. 66. Head and mesosoma, dorsal view. 67. Apex of metasoma, dorsal view. Scale in millimeters.

Figs. 7–13. 7. Nixonia flavocincta, n.sp., head, frontal view (OSUC 146461); 8. N. atra Masner, maxillary palpomeres 2–5 (OSUC 146405). 9. N. watshami, n.sp., maxillary palpomeres 1–5 (OSUC 146418). 10. N. atra, mandible (OSUC 146405). 11. N. krombeini, n.sp., mandible (OSUC 146436). 12. N. krombeini, head, frontal view (OSUC 146436). 13. N. watshami, head, frontal view (OSUC 146418).

Figs. 68–73. Nixonia watshami, n.sp. 68. Lateral habitus (OSUC 146454). 69. Head, frontal view (OSUC 146454). 70. Head and mesosoma, dorsal view (OSUC 146454). 71. Apex of metasoma, dorsal view (OSUC 146456). 72. Antenna, ventral view (OSUC 146457). 73. Mouthparts, lateral view (OSUC 146457). mp4, maxillary palpomere 4; s, paired multiporous basiconic sensilla. Scale in millimeters.