Trogloembolemus Olmi, Mita et Guglielmino

Olmi, Massimo, Mita, Toshiharu & Guglielmino, Adalgisa, 2014, Revision of the Embolemidae of Japan (Hymenoptera: Chrysidoidea), with description of a new genus and two new species, Zootaxa 3793 (4), pp. 423-440 : 434-437

Genus Trogloembolemus Olmi, Mita et Guglielmino , gen. nov.

( Fig. 6 )

Type species. Trogloembolemus fujiei Olmi, Mita & Guglielmino , sp. nov.

Diagnosis. Female ( Figs 6–8 ): micropterous; head and mesosoma fusiform; head with dorsal side flat; maxillary palpi 4-segmented; labial palpi 2-segmented; third segment of maxillary palpi broadened; ocelli absent; eyes strongly reduced; first antenna geniculated; antennal segment much longer than segment 3; pronotum without track of median longitudinal furrow; scutellum trapezoidadl, metanotum reduced to very narrow longitudinal carina; tibial spurs 1/2/2. Male: unknown.

Distribution. Japan (Honshu).

Hosts. Unknown.

World species. Type species only.

Etymology. The name of the genus is a composition of troglo - (= cave) and embolemus , meaning an embolemid living in caves or in deep cracks of the soil.

Remarks. In Trogloembolemus the female is micropterous, so that the new genus is close to Embolemus . The main differences between the females of these two genera are the following: in Trogloembolemus: head + mesosoma fusiform ( Figs 6 B, C); tarsi very slender ( Fig. 7 ); eye strongly reduced ( Fig. 6 A); scutellum very long and narrow, alutaceous, trapezoidal, with shorter base posterior ( Fig. 6 B); metanotum reduced to very narrow longitudinal carina forming a bridge upon the first region of propodeum ( Fig. 6 B); in Embolemus : head + mesosoma not fusiform ( Fig. 8 ); tarsi normal ( Fig. 8 ); eye normal ( Figs 2 A, 3A, 4A, 5A); scutellum subcircular ( Figs 2 B, 3B, 4B, 5B); metanotum short and transverse ( Figs 2 B, 3B, 4B, 5B).

1. Trogloembolemus fujiei Olmi, Mita et Guglielmino , sp. nov. ( Figs 6 , 7 , 9)

Description. Female. Micropterous; length 3.8 mm. Completely testaceous-ferruginous. Antenna geniculated, filiform, without rhinaria, slightly longer than head + mesosoma + metasoma (70:61); antennal segments in following proportions: 46:6:19:19:19:18:17:17:16:18. Head + mesosoma fusiform ( Fig. 7 ). Head ( Fig. 6 A, C) shiny, alutaceous, covered with short hairs, unsculptured, with dorsal side flat; anterior region of dorsal side very tapering ( Fig. 6 C); occipital carina complete; ocelli absent; eye ( Fig. 6 A) very small, reduced to small dark spot, approximately 0,0 5 as long as head (2:36); region of face from clypeus to antennal toruli with two hardly visible, incomplete, convergent longitudinal and median sutures. Maxillary palpi 4-segmented; labial palpi 2-segmented. Third segment of maxillary palpi broadened. Pronotum shiny, alutaceous, covered with short hairs, with two fine lateral incomplete carinae beginning at posterior border and reaching about 0.5 × length of pronotum; anterior collar very short; disc long, without median longitudinal groove; pronotal tubercle reaching tegula. Scutum very short, ovoidal, alutaceous, without tracks of median furrow. Notauli absent. Parapsidal lines present near lateral margins of scutum. Scutellum very long and narrow, alutaceous, trapezoidal, with shorter base posterior ( Figs 6 B, C). Metanotum reduced to very narrow longitudinal carina forming a bridge upon the first region of propodeum ( Figs 6 B, C, 7). Meso-metapleural suture complete. Mesopleuron and metapleuron dull, rugose, transversely striate. Propodeum dull, with dorsal surface granulated, not rugose, with spiracles normally prominent, with two lateral pointed apophyses on sides of posterior surface; dorsal surface without median depression situated at border between anterior and posterior surface; dorsal surface with two lateral carinae connecting spiracles to pronotal tubercles, by running laterally to metanotum, scutellum and scutum. Posterior inclined surface of propodeum weakly rugose, with some transverse carinae. Fore wing strongly reduced, slightly longer than tegula, reaching the depression at anterior border of propodeum. Hind wing absent. Tarsi very slender. Petiole short. Tibial spurs 1/2/2.

Male. Unknown.

Material examined. Holotype, ♀: JAPAN: Honshu, Wakayama Prefecture, Susami Town, Esumi, 40 m, 1.XII.2010, S. Fujie leg. (TUA).

Etymology. The species is named fujiei after the name of the collector, Mr. Fujie.

Remarks. The only known specimen of this species has been collected in a slope ( Fig. 10 ) at a depth of two metres below the ground surface. It is the first species of Embolemidae with troglobitic habitus and probably behaviour. Probably its hosts are nymphs of unknown troglobitic Cixiidae feeding on roots in caves or in cracks of the soil. It has been collected during a heavy rainy day by a collector of troglobitic Carabidae (Coleoptera) .

Figures

FIGURE 2. Embolemus honshuensis, female holotype. A. Head in lateral view. B. Mesosoma in dorsal view. C. Outline of border between anterior and posterior surface of propodeum. Scale bar 1.1 mm for A, 0.7 mm for B, 0.4 mm for C.

FIGURE 6. Trogloembolemus fujiei, female holotype. A. Head in lateral view. B. Mesosoma in dorsal view. C. Head + mesosoma in dorsal view. Scale bar 1.1 mm for A, 0.5 mm for B, 1.3 mm for C.

FIGURE 7, 8. 7. Trogloembolemus fujiei, female holotype in dorsal view. Length 3.8 mm. 8. Embolemus ruddii, female from Italy, Mt. Corvo (from Olmi 1996). Length 3.5 mm.

FIGURE 10. Photo of the slope where the holotype of Trogloembolemus fujiei has been collected. Esumi (Wakayama Prefecture, Japan) (courtesy of Mr. Fujie).