Megaprosternum Azevedo, New Genus, 2006

Azevedo, C. O., 2006, Two new genera of Sclerodermini (Hymenoptera: Bethylidae; Epyrinae) with large, scolebythid-like prosternums, Zootaxa 1191, pp. 35-47 : 37-46

Megaprosternum Azevedo, New Genus

Type species. Megaprosternum longiceps sp. nov. by present designation.

Diagnosis

Males. Body flattened dorsoventrally. Pronotal disc with posterolateral corners overlapped by mesoscutum, and extending laterally beyond anterior margin mesoscutum. Prosternum very large, pentagonal. Forewing with subcostal vein. Females apterous. Genitalia with paramere elongate, cuspis wide, aedeagus slender. Females. Similar to males except by being apterous.

Description of male

Body flattened dorsoventrally. Mandibles not elongate, overlapping at about one third of their length. Eyes situated forward on head. Antennal pedicel longer than segment III, much flattened. Pronotal disc evenly convex in cross section, slightly depressed anteriorly, lateral faces strongly concave, posterolateral corners slightly overlapped by mesoscutum, and extending laterally beyond anterior margin mesoscutum forming rounded lobe beyond tegulae. Scutellum separated from mesoscutum by suture. Propodeal disc in full contact with scutellum. Prosternum very large, pentagonal; width at least 2.5x median length of propleuron. Forewing with subcostal vein and small linear stigma ( Figs. 5 , 9 ). Legs flattened, all trochanters inserted distally on coxae. Posterior margin of tergites and sternites not emarginated. Genitalia with paramere elongate, basiparamere short, cuspis large aedeagus slender and basal ring present.

Description of female

Similar to males except by being apterous and having posterior margin of tergites II – V and of sternites III–VI twice emarginated at posterior margin.

Etymology The generic epithet [mega from Latin = large, pro from Latin = before, sternum from Greek = sternum] refers to huge prosternum. Gender: neuter.

Key to species of Megaprosternum

1. Apterous ( Fig. 18 ); females ....................................................... M. longiceps sp. nov. ­ Forewing fully developed ( Fig. 5 ); males.................................................................. 2 2(1). Head about 1.6x as long as wide, rectangular, sides subparallel ( Fig. 1 ); ocelli nearly touching one another ................................................................. M. longiceps sp. nov. ­ Head about 1.2x as long as wide, sides convergent posteriorly ( Fig. 6 ); ocelli distant each other about 0.5x their diameter ...................................... M. pentagonal sp. nov.

Megaprosternum longiceps Azevedo, New Species

Diagnosis Male. Head very long, about 1.6x as long as wide. Ocelli nearly touching one another.

Description of male.

Length. Body 3.33 mm. Forewing length 2.23 mm. Body entirely very flattened, head 0.26x as high as long in lateral view. Color. Body, mandibles, antennae, coxae, trochanters, and femora dark castaneous, palpi, tibiae, and tarsi castaneous.

Head ( Fig. 1 ). Mandibles with three apical, sharp teeth ( Fig. 2 ). Clypeus extremely short, apical margin straight, surface concave, extending back into frons for about half length of eyes, pentagonal, slender and polished with pair of lateral carinae which separate it from frons. First four antennal segments in ratio of 15:10:8:10, scape flattened medially, segment XI distinctly longer than wide, pubescence suberect with some erect setae outstanding pubescence. Eyes ovoid, setose. Frons coriaceous with some small and very sparse punctures. WH 0.63x LH, WF 0.41x WH, WF 0.76x HE, OOL 2.56x WOT, frontal angle of ocellar triangle acute, posterior ocelli distant from vertex crest 0.5x DAO. Vertex slightly convex, corners rounded, temples subparallel. VOL 1.68x HE. Occipital carina absent. Palpal formula 5:1.

Mesosoma ( Fig. 3 ). Mesoscutum about as long as pronotal disc, separated from scutellum by dark, very narrow and shallow line. Notauli and parapsidal furrows absent. Scutellum without groove or pits, posterior margin slightly convex. Metanotum reduced to hind wing opening. Propodeal disc with posterior half distinctly narrower than anterior half, median length 1.54x median width, without anterior and posterior transverse carinae, median and lateral carinae, disc coriaceous, stronger posteriorly, propodeal spiracles located at midlength of disc level with mesoleg opening, completely directed outward, declivity reduced. Prosternum with width 3.0x median length of propleuron ( Fig. 4 ). Mesopleuron coriaceous, central pit small and shallow. Profemur 3.4x long as wide, tibiae not spinose, all claws simple.

Metasoma. Weakly coriaceous. Setae long, particularly in distal segments. Hypopygium with three anterior sharp stalks, median one about as long as plate, as wide as anterior margin at base and progressively narrowing to apex, lateral ones short and slightly directed outward, posterior margin barely convex, lateral margins strongly constricted anteriorly.

Genitalia ( Figs. 10–11 ). Paramere evenly narrow, apex narrowly rounded, about 3x as long as basiparamere. Cuspis laminar, very wide, even wider basally, wider than paramere, apex truncate with corners broadly rounded, lateral margins converging apically, as high as two thirds of paramere. Digitus with apex directed outward, as high as cuspis. Basivolsella not fused to basiparamere, basal margin rounded and nearly reaching genital ring. Aedeagus slightly wider medially, as high as cuspis, apex strongly emarginated medially with expansion directed downward, apodeme short, not dilated basally.

Material examined Holotype, male, FIJI, Viti Levu , Nandaravatu, Microwave St [atio]n, 1100 m, 16–23.VIII. [19]78, Malaise trap, S. & J. Peck col. ( ANIC).

Etymology The specific epithet from Latin refers to very elongate head.

Megaprosternum pentagonal Azevedo, New Species

Diagnosis

Males. Head about 1.2x as long as wide, sides convergent posteriorly. Ocelli not touching each other. Macropterous. Females. Similar to males except by having head with sides parallel and wings absent.

Description of male

Length. Body 2.56 mm. Forewing length 1.59 mm. Body entirely very flattened, head 0.31x as high as long in lateral view. Color. Body, coxae, and femora dark castaneous, mandibles, antennae, palpi, trochanters, tibiae and tarsi castaneous.

Head ( Fig. 6 ). Mandibles with three apical, sharp teeth ( Fig. 7 ). Clypeus extremely short, apical margin barely convex, extending back frons for about half length of eyes, triangular and polished, without median carina. First four antennal segments in ratio of 12:6:5:5, scape flattened medially, segment XI distinctly longer than wide, pubescence suberect with some erect setae outstanding pubescence. Eyes ovoid, setose. Frons coriaceous with some small and very sparse punctures. WH 0.86x LH, WF 0.57x WH, WF 1.2x HE, OOL 2.26x WOT, frontal angle of ocellar triangle acute, posterior ocelli distant from vertex crest 0.5x DAO. Vertex slightly convex, corners rounded, temples slightly diverging anteriorly. VOL 1.27x HE. Occipital carina absent. Palpal formula 5:3.

Mesosoma ( Fig. 8 ). Mesoscutum about as long as pronotal disc, separated from scutellum by very narrow and shallow line. Notauli absent, but replaced by black strip anteriorly. Parapsidal furrows complete, weak and converging posteriorly. Scutellum without groove or pits, posterior margin slightly convex. Metanotum reduced to hind wing foramen. Propodeal disc progressively narrow posteriorly; median length 1.1x median width, without anterior and posterior transverse carinae and median carina, lateral carinae very weak, converging in declivity and reach propodeal foramen, disc coriaceous, stronger posteriorly, propodeal spiracles located at midlength of disc level with mesoleg foramen, and interrupting lateral carina and completely directed outward. Prosternum with width 3.0x median length of propleuron. Mesopleuron coriaceous, central pits small. Profemur 2.4x long as wide, tibiae not spinose, all claws simple.

Metasoma. Weakly coriaceous. Setae long, especially in distal segments. Hypopygium with three anterior sharp stalks, median one about as long as plate, as wide as anterior margin at base and progressively narrowing to apex, lateral ones short and slightly directed outward, posterior margin straight, lateral margins strongly constricted anteriorly ( Fig. 12 ).

Genitalia ( Figs. 13 – 14 ). Paramere slightly narrower just above base, apex rounded, about 3x as long as basiparamere. Cuspis laminar, very wide, nearly as wide as paramere, apex truncate with corners narrowly rounded, lateral margins parallel, as high as two thirds of paramere. Digitus with apex directed outward, as high as cuspis. Basivolsella not fused to basiparamere, basal margin rounded and nearly reaching genital ring. Aedeagus slightly wider medially, as high as cuspis, apex strongly emarginated medially with expansion directed downward, apodeme short, not dilated basally.

Description of female

Length. Body 2.61 mm. Color. Body wholly very flattened, head 0.29X as high as long in lateral view. Color. Body, tegulae, coxae, trochanters and femora dark castaneous, mandibles, antennae, palpi, tibiae and tarsi castaneous.

Head ( Figs. 15–16 ). Mandibles with three apical, sharp teeth ( Fig. 17 ). Clypeus retracted, apical margin concave, extending back frons for more than half length of eyes, triangular and polished, without median carina. First four antennal segments in ratio of 14:4:3:3, scape flattened medially, segment XI slightly longer than wide, pubescence subappressed, some suberect setae outstanding pubescence. Eyes ovoid, setose. Frons coriaceous with some small and very sparse punctures. WH 0.76x LH, WF 0.69X WH, WF 1.57x HE, OOL 4.0x WOT, frontal angle of ocellar triangle acute, posterior ocelli distant from vertex crest 0.67x DAO. Vertex slightly convex, corners rounded, temples parallel. Head rectangular. VOL 1.71x HE. Occipital carina absent. Palpal formula 5:3.

Mesosoma ( Fig. 18 ). Mesoscutum 0.44x as long as pronotal disc, separated from scutellum by inconspicuous line. Notauli absent. Parapsidal furrows complete, weak and converging posteriorly. Scutellum transverse, without groove or pits, posterior margin slightly convex. Metanotum completely absent dorsally. Propodeal disc reaching tegulae laterally, median length 1.1x median width, without anterior and posterior transverse carinae and median carina, lateral carinae very weak, converging in declivity and reach propodeal foramen, disc coriaceous, stronger posteriorly, propodeal spiracles located at midlength of disc at mesoleg foramen level, and interrupting lateral carina and completely directed outward. Prosternum with width 2.67x median length of propleuron. Mesopleuron coriaceous. Tegulae present, 0.05 mm long. Profemur enlarged, 2.0x long as wide, tibiae not spinose, all claws simple.

Metasoma. Weakly coriaceous. Setae long, particularly in distal segments.

Material examined

Holotype, male, AUST [ RALIA], Q[ueens]l[an]d, Mount Glorious , 27º19´54" S 152º45´29" E, 29.XI – 5.XII.1997, Malaise [trap] 3, T. Hiller col. ( ANIC) . Allotype, female, AUST [ RALIA], Q[ueens]l[an]d, M[oun]t Glorious, 630 m, dry sclerophyl Eucalyptus forest, S. F., 28.II – 9.III. [19]84, L. Masner col. ( ANIC) .

Remarks

The shape of the antenna, mandible teeth, ocellar triangle and mesosoma are very similar in both sexes, but sexual dimorphism is strong. Males have the wings fully developed, the clypeus short but more projected than the anterior margin of torulli, and the head with sides converging backward, whereas females are apterous, the clypeus is shorter than the anterior margin of torulli, the head is rectangular and the profemora is thicker than those of males.

Etymology The specific epithet from Greek refers to pentagonal shape of prosternum.

Solepyris Azevedo, New Genus

Type species. Solepyris unicus sp. nov. by monotypy and present designation.

Diagnosis

Female. Pronotal disc with lateral faces strongly concave. Forewings only with subcostal, basal, transverse median and anal veins; median and submedian cells fused by absence of median vein, subcostal vein much dilated distally, prostigma small and stigma absent.

Description of female

Body slightly flattened. Mandibles not elongate. Eyes situated forward on head.

Pronotal disc slightly depressed anteriorly, lateral faces strongly concave. Scutellum separated from mesoscutum by suture. Forewings only with subcostal, basal, transverse median and anal veins; median and submedian cells fused by absence of median vein, subcostal vein much dilated distally, prostigma small and stigma absent ( Fig. 21 ). Tibial spur formula 1:1:1. Male unknown.

Remarks This genus is easily recognized by forewing venation, which has only one wide closed cell.

Etymology The generic epithet [solus from Latin = single, Epyris = genus name] refers to number of closed cells in forewings. Gender: male.

Solepyris unicus Azevedo, New Species

Description of female Length. Body 3.92 mm, LFW 2.04 mm.

Color. Body dark castaneous, clypeus, mandibles, antennae and legs castaneous, except coxae and femora darker, wings hyaline, veins dark castaneous.

Head ( Fig. 19 ). Mandibles narrower apically with three apical teeth, uppermost shorter ( Fig. 20 ). Clypeus polished, extremely short, extending backward into frons, apical margin convex and situated behind level of anterior margin of torulli, without median carina. First four antennal segments in ratio of about 3:1:1:1, flagellomere longer than wide. Antennal torulli distant each other 1.8x their own diameters. Eyes slightly ovoid with sparse setae. Frons coriaceous with few sparse small punctures. Malar space narrow, 0.4x basal width of mandible. LH 1.12x WH, WF 0.59x WH, WF 1.32x HE, ocellar triangle compact, OOL 2.23x WOT, frontal angle of ocellar triangle acute, posterior ocelli distant from vertex crest 3.33x DAO. Vertex broadly convex. Temples subparallel. VOL 1.32x HE. Occipital carina present, but weak. Palpal formula 6:3, distal segments slightly flattened.

Mesosoma ( Fig. 19 ). Thorax coriaceous. Pronotal disc with posterior margin straight in dorsal view. Notauli absent. Parapsidal furrows complete but very weak. Scutellum slightly shorter than mesoscutum, scutellar groove nearly straight, not crossing all anterior width of scutellum, shallow, ends little dilated and angled backward. Propodeal disc 1.0x as long as median width, transverse anterior carina defined but narrow, median carina not defined, instead there is areolate basal triangle with median irregular striae, otherwise disc weakly areolate, posterior transverse carina present; spiracles located at lateral of propodeum, anterior corner with oblique foveolate groove; declivity polished, without median carina. Propleuron wide. Prosternum triangular with anterior margin convex, lateral margins hardly concave, slightly longer than wide; width 0.82x length of propleuron 0.56x as long as profemur, posterior vertex narrow but rounded and surpassing anterior margin of pleurosternum. Mesopleuron weakly coriaceous, little bulging in dorsal view, central pit small rounded. Mesosternum with median groove, posterior margin of mesosternum and metasternum carinate and foveolate. Legs not spinose. Profemora 2.0x as long as wide. Metalegs with coxae very closed each other, tibiae longer than femora, basitarsi much longer than second tarsomere. Claws simple, arched and with dilated base.

Metasoma. Nearly polished, pubescence of posterior half of sternites dense and long, especially apically, transverse section elliptical.

Material examined

Holotype, female: ECUADOR, Pich [incha], Rio Palengue, II.1976, Mal [aise] tr[ap], J. Bellwood col. ( CNCI) . Paratypes, 2 females: BRAZIL, Minas Gerais, Belo Horizonte, Ecological Station of UFMG, 25–26.xi.1996 , Malaise trap; J. C. R. Fontenelle col. ( UFMG) .

Variation

LH 1.13–1.15x WH, WF 0.57–0.6x WH, WF 1.1–1.2x HE, OOL 2.3x WOT, posterior ocelli distant from vertex crest 2.3x DAO, VOL 1.0x HE, triangle basal of propodeal disc slightly more striate and polished behind, prosternum of specimen from Ecuador has posterior vertex wider and small stigma in forewing. The main variation between Brazilian paratypes and Ecuadorian holotype is that the paratypes have larger eyes, making temple smaller and consequently index VOL/HE smaller. The disjunct distribution and variation in eye size does not justify splitting in two separate species.

Etymology The specific epithet from Latin refers to number of closed cells in forewings.

Discussion

The shape of pronotal disc with posterolateral corners that are overlapped by the mesoscutum and that extend laterally beyond anterior margin mesoscutum is peculiar to Megaprosternum and Solepyris . These genera also have in common a very large prosternum, which resembles species of Scolebythidae . The prosternum in Bethylidae is small, normally much smaller than procoxae, and usually with concave surface. In Megaprosternum the prosternum is huge and pentagonal ( Fig. 4 ), whereas in Solepyris it is subtriangular and not as large as in the former genus ( Fig. 21 ).

The bodies of Megaprosternum and Solepyris are extremely flattened and are similar to that of Alongatepyris and Thlastepyris . Evans (1973) suggested that bethylid species having the body extremely flattened likely attack insects living under bark. As such these two genera are probably closely related. Nonetheless, female of Megaprosternum is apterous, whereas in Solepyris female is fully winged.

The wing venation among the genera of Sclerodermini is very different, which helps make generic determinations. Megaprosternum is easily recognized by the great reduction of wing venation. The forewings have only the subcostal vein, which makes it different of all other genera in the tribe. Solepyris also have reduction in wing venation, with only one closed cell in the forewing, but it is not as reduced as in Megaprosternum . Even so, wing venation makes this genus easily recognizable.

Figures

FIGURES 1–5. Megaprosternum longiceps sp. nov. male. 1. Head in dorsal view; 2. Mandible in frontal view; 3. Mesosoma in dorsal view; 4. Prosternum in ventral view; 5. Forewing in dorsal view.

FIGURES 6–9. Megaprosternum pentagonal sp. nov. male. 6. Head in dorsal view; 7. Mandible in frontal view; 8. Mesosoma in dorsal view; 9. Forewing in dorsal view.

FIGURES 15–18. Megaprosternum pentagonal sp. nov. female. 15. Head in dorsal view; 16. Head in lateral view; 17. Mandible in frontal view; 18. Mesosoma in dorsal view.

FIGURES 10–14. Megaprosternum gen. nov. male. 10–11. M. longiceps sp. nov. 10. Genitalia in dorsal view; 11. Apex of aedeagus in latero­ventral view; 12–14. M. pentagonal sp. nov. 12. Hypopygium in ventral view.; 13. Genitalia in dorsal view; 14. Genitalia in ventral view. (scale bar = 250 m)

FIGURES 19–21. Solepyris unicus sp. nov. female. 19. Head, mesosoma and forewing in dorsal view; 20. Mandible in frontal view; 21. Prothorax, procoxae and trochanters in ventral view. (scale bar = 250 m)