Zethus (Zethus) stangei Porter, 2008

Porter, Charles C., 2008, A remarkable new species of Zethus Fabricius (Hymenoptera, Vespidae, Eumeninae) from Costa Rica, Insecta Mundi 2008 (27), pp. 1-4 : 2-3

Zethus (Zethus) stangei Porter , new species

( Fig. 1 -4)

Diagnosis. Middle tibia with 1 apical spur. Sternite II with a strong, flattened medio-apical bulge ( Fig. 2 ). Stem of tergite II much shorter than stem of tergite I, very broad, 3.5 as wide as long. Male clypeus very short ( Fig. 3 ). Male mandibles grossly enlarged ( Fig. 3 ). Tergite II sharply raised above its distal lamella, the lamella itself more than 2 mid ocellus diameters in length. Tegula strongly narrowed and prolonged posteriorly. The medio-apical bulge on sternite II and the peculiarly modified male clypeus and mandibles are unique in the genus Zethus . Other characters are summarized in the following description.

Description: Male Holotype. Length to apex of tergite II from 17.5-20 mm. Black with yellowish orange as follows: mandible, antenna, ocular spot, anterior and mesal margin of pronotum, tegula, parategula, wings slightly, and legs in part. Notum and mesopleuron with dense pale setae. Interantennal area low and mostly smooth. Notauli complete, somewhat weakened anteriorly toward base of scutum. Scutum coarsely and densely punctate. Apical lamella of propodeum much abbreviated, not differentiated from rest of submarginal carina. Hind face of propodeum mat, minutely striato-granulate, with a well defined median channel, its lateral carina weakly and irregularly defined, not percurrent. Petiole dorsally with scattered small and large punctures and obscure shagreening. Mandible, clypeus and antenna as in Fig.3 . Pronotum rounded between humerus and tegula; subhumeral area broad; pronotal lamella higher than one mid ocellus diameter. Tegula with outer margin evenly curved, except narrowed and produced apicad into a large, elongately triangular process which extends well beyond apex of parategula. Tergite II with numerous strong, mostly sparse punctures, and fine shagreening but becoming smooth and polished toward apex.

Female Paratype. Differs from male as follows. Scutum partly striato-punctate. Clypeus polished, sparsely punctate, with weak but rather broad well spaced striae which radiate from base a variable distance toward apex, its apical margin nearly truncate. Tergite II similar to male but more extensively smooth and polished, finely shagreened only on basal third. Front basitarsus with dense and short but very strong reddish peglike spines.

Type material. Holotype male, COSTA RICA, Alaju. Prov. , Est. San Ramón Oeste, 620 m, 3-19- IV-1999, F. Quesada [ FSCA] . Paratype female,

COSTA RICA, Guanacaste Prov., Estac. Cacao, SW side Volcán Cacao , 1000-1400 m, XI-XII-1989, R . Blanco and C. Chávez [ FSCA] .

Other material. Bohart and Stange (1965) record two additional specimens of this species, mistakenly ascribed to Z. magretti Zavattari (1912) , a female from Costa Rica (Juan Viñas, UCD) and a male from Panama (Volcán de Chiriquí, BMNH). These specimens have not been reexamined but Bohart and Stange’s description leaves no doubt that they belong here.

Relationships. This monobasic group is unique in having a medio-apical bulge on sternite II and the male mandible greatly enlarged with a corresponding reduction in the size of the clypeus. Otherwise, as observed by Bohart and Stange (1965),

the “female is similar to species in the coeruleopennis group.” Indeed, when Stange reexamined the holotype female of Zethus magretti Zavattari at Turin he was able to assign that species to the coeruleopennis group.

Collections

BMNH. Department of Entomology, British Museum of Natural History, Cromwell Rd., London SW7 5BD, England.

FSCA. Florida State Collection of Arthropods , Florida Department of Agriculture and Consumer Services, P.O. Box 147100, Gainesville , Florida 32614-7100.

UCD. Bohart Museum of Museum, University of California , 1124 Academic Surge, Davis, California 95616.

Figures

Figure 1. Zethus stangei, male holotype, lateral view of entire insect showing habitus. Note that the stem is very short.

Figure 2-3. Zethus stangei. 2) Male holotye, ventral view of abdomen showing medio-apical bulge on sternite II. 3) Male holotype, front view of head showing the grossly enlarged mandibles and abbreviated clypeus. 4) Female paratype, front view of head showing large, sparsely punctate clypeus and median sized mandibles.