Xenapates goergeni, Koch, 2007

Koch, Frank, 2007, Three new species and three new records of Xenapates from Togo (Hymenoptera: Symphyta: Tenthredinidae), African Invertebrates 48 (2), pp. 111-120 : 114-115

Xenapates goergeni sp. n.

Figs 5 , 12

Etymology: This species is named after Dr Georg Goergen, head of the Biodiversity Centre (IITAC).

Description:

Female.

Head black; mandible reddish brown with pale yellow basal half; clypeus and labrum pale yellow. Thorax black with following pale yellow: ventrolateral markings of pronotum, postspiracular sclerite, mesosternum and ventral part of mesopleuron, anterior margin of mesepimeron; mesopleuron between blackish dorsal and pale yellow ventral part with a very inconspicuously whitish longitudinal strip. Legs yellow; coxae whitish, distal tarsomeres brown. Wings uniformly infuscate; costa, subcosta, stigma and rest of venation brownish black. Abdomen yellow; sawsheath black, valvifer 2 yellow.

Head from above slightly narrowed behind eyes. Antenna 1.7× as long as maximum head width. POL:OOL=1.0:1.8–1.9 (1.8 HT). Postocellar area: width:length = 1.0:1.4; lateral furrows conspicuously convex. Frontal area with very obtuse anterior crossridge, medially interrupted; lateral furrows convex, ending scrobiculate at anterior crossridge, lateral tubercles inconspicuously developed; interantennal groove very shallow, crescentshaped. Vertex, frons and gena impunctate, strongly shining. Base of mandible scarcely sculptured, moderately shining. Pubescence on vertex brown, about as long as diameter of a lateral ocellus. Thorax nearly impunctate, strongly shining.Abdomen without microsculpture, strongly shining.

Serrulae 9–11 as in Fig. 5 .

Length: 7.8–8.0 mm.

Male. Unknown.

Holotype:^“ TOGO: Kloto , forest area, Oct. 2001, leg.: G. Goergen ”; [red] “ Holotypus, Xenapates goergeni sp. n., det.: F. Koch ” ( MNHU).

Paratype: 1^same data as holotype ( IITAC) .

Host plant: Unknown.

Distribution: Togo ( Fig. 1 ).

Remarks:In the Xenapates key by Koch (1995), the new species is similar to X. pectoralis Forsius, 1927. The anterior crossridge of the frontal area of X. pectoralis, however, is not medially interrupted, and the wings are very slightly bicoloured with a more infuscate apical and a paler basal half. Additionally, X. goergeni differs in the very indistinct or not visible whitish longitudinal strip on the mesopleuron. This character is, however, also variable in X. pectoralis, from mostly conspicuously white to rarely indistinctly visible. For accurate identification it is therefore essential to examine the shapes of the serrulae, which are distinctly different ( Figs 5, 6 ). Furthermore, X. pectoralis is distributed in south-eastern Africa ( Fig. 1 ).

It is very difficult to describe the variability of the new species based on only two specimens. Nevertheless, the distal flagellomeres of the paratype are dirty whitish ventrally, the metascutellum is yellow laterally, and the crossridge of the frontal area is more conspicuously interrupted.

Figures

Figs 2–6. Serrulae 9–11 of Xenapates species:(2) X.atratus sp. n., (3) X.braunsi (Konow), (4) X. gabunensis (Konow), (5) X. goergeni sp. n., (6) X. pectoralis Forsius.

Figs 11–13. (11) Xenapates atratus sp. n., (12) X. goergeni sp. n., (13) X. togoensis sp. n.

Fig. 1. Distribution of Xenapates species that are relevant to the differential diagnosis of the new species.