Lamnatibia, Palacio & Saaksjarvi

Palacio, Edgard, Sääksjärvi, Ilari E. & Vahtera, Varpu, 2007, Lamnatibia, a new genus of the Polysphincta group of genera from Colombia (Hymenoptera: Ichneumonidae; Pimplinae), Zootaxa 1431, pp. 55-63 : 57-59

Genus Lamnatibia Palacio & Sääksjärvi gen.n.

( Fig. 2 )

Type-species: Lamnatibia andina sp.n.

Description. Small sized insects (fore wing length 4.0– 5.2 mm) which are patterned orange yellow, black and white. Mandibles slender strongly tapered from base to apex, with upper tooth quite straight and distinctly longer than lower tooth. Clypeus not divided into basal and apical parts; in profile moderately convex; apical margin slightly concave. Maxillary palp 5-segmented, not exceptionally long reaching back as far as fore coxa. Labial palp 4-segmented. Occipital carina completely absent. Subocular sulcus absent. Pronotum rather short, with anterior margin reflexed and curved backwards in a point, without a mediodorsal longitudinal crest, and with a shallow transverse furrow. Epomia indistinct, discernible only in the lower horizontal part, or completely absent in smaller individuals. Mesoscutum simple, without crestlike carinae in front of each notaulus. Notauli weakly impressed anteriorly. Epicnemial carina completely absent. Mesopleural suture weakly angled centrally. Submetapleural carina complete. Propodeum quite long and evenly declivous, without posterolateral swellings; dorsally without carinae enclosing any area. Pleural carina complete. Propodeal spiracle subcircular. Fore and middle femora basally swollen and ventrally expanded to form a longitudinal lamelliform tooth-like projection. Fore and middle tibia with a longitudinal lamelliform ridge extending from base to apex on ventral surface. Hind tibia without a glabrous longitudinal furrow on inner surface. Claws of females with a very large basal lobe and without a fringe of closely spaced hairs. Fore wing with vein 3rs-m absent. Hind wing with first abscissa of M + Cu1 strongly bowed well distal to its centre; distal abscissa of Cu1 absent, its position indicated by a very weak angulation of cu-a. Metasoma with tergite 1 moderately slender; remainder tergites stout. Tergite 2 with shallow oblique grooves cutting off depressed triangular areas anterolaterally; tergite 3 almost smooth and convex; remainder tergites smooth and convex. Female with subgenital plate uniformly but weakly sclerotized. Ovipositor very weakly curved upwards at the apex, 0.85 times the length of the hind tibia, and with apex tapered to sharp point; apical teeth indistinct.

Diagnosis. Lamnatibia is a very distinctive genus. It can be easily separated from other genera of the Polysphincta group by the specialized shape of the fore and middle femora, the presence of a thin, longitudinal ridge in the inner face of the fore and middle tibiae, and the combined absence of occipital and epicnemial carinae.

Male. Unknown.

Etymology. The generic name is from the Latin lamnae (lamella) referring to the longitudinal lamelliform ridge of the fore and middle tibia.

Remarks. Lamnatibia belongs in the Polysphincta group of genera (Gauld et al., 2002) as it has the mandibles slender and very strongly tapered, lobe of maxilla enlarged to occlude oral fossa, pedicel strongly inflated, fifth tarsomere of fore leg of female very swollen, and hind tarsus with pulvillus enlarged, projected conspicuously beyond apex of claw (Gauld et al. 2002; Gauld & Dubois 2006). In appearance, Lamnatibia resembles the genera Flacopimpla , Eruga and Zatypota , but can be easily distinguished from them, and all the other neotropical members of the Polysphincta complex, by the specialized shape of fore and middle femora ( Table 1 ). Nothing is known about the biology of the genus.

Eruga Flacopimpla Lamnatibia Zatypota

Upper tooth of mandible Upper tooth of mandible Upper tooth of mandible Upper tooth of mandible

unspecialized unusually long and up- unspecialized unspecialized curved

Figures

FIGURE 2. Habitus of Lamnatibia andina Palacio & Sääksjärvi sp. n. Holotype female.