A taxonomic study on the genus Ettchellsia Cameron, with descriptions of three new species (Hymenoptera, Megalyridae, Dinapsini)

Abstract Three new species of Ettchellsia Cameron, namely, Ettchellsia ignita sp. n. from Peninsular Malaysia and Borneo, Ettchellsia nigripes sp. n. from Sulawesi and Ettchellsia reidi sp. n. from Borneo are described and illustrated. A key to the species of Ettchellsia is provided based on females.

introduction Cameron (1909) described a remarkable new wasp genus from Borneo that he dedicated to his housekeeper, Mary Ettchells. Cameron found the insect so unusual that he struggled to place it to family, and debated if it should be placed into a new family. Subsequent authors (Baltazar 1961;Shaw 1988Shaw , 1990Vilhelmsen et al. 2010) have clarified the placement of Ettchellsia Cameron in the family Megalyridae. Ettchellsia Cameron 1909 is a small genus comprising three described species (Cameron 1909;Baltazar 1961;He 1991). Ettchellsia species show an Indomalayan distribution, i.e., E. piliceps Cameron occurring in Borneo, E. philippinensis Baltazar occurring in Philippines and E. sinica occurring in Yunnan, China. Shaw (1990) defined Ettchellsia as a monophyletic genus based on three synapomorphies: the rugose hind tibia, unique pattern of propodeal carinae (as in Figs 10-12), and smooth posterior border of the mesopleuron, without a row of foveae separating the mesopleuron and metapleuron. Shaw (1990) also examined specimens from Thailand and Viet Nam, which he regarded as range extensions and variations of Ettchellsia piliceps Cameron. One specimen from Taiwan was not placed to species because it was a male. Vilhelmsen et al. (2010) also referred to unidentified species of Ettchellsia from Taiwan and Thailand. According to recent phylogenetic studies, the genus Dinapsis Waterson (distributed in the Afrotropical region) was strongly suggested to be the closest relative of Ettchellsia (Shaw 1990;Vilhelmsen et al. 2010). Ettchellsia species are quite rare; however, recently some specimens were obtained from Peninsular Malaysia, Sulawesi and Kalimantan. They were identified by us as three different new species. These findings and recent taxonomic works on the genus Carminator Shaw, the other genus of the family found in Asia (Mita et al 2007;Mita and Konishi 2011) may imply the megalyrid species diversity of the Indomayan region is still not clarified well. The biology of Ettchellsia has remained unknown, and no distributional areas are reported except for type localities. It is almost the same case with Carminator. Based on a knowledge of other Megalyridae, Ettchellsia is presumed to be an idiobiont ectoparasitoid, probably attacking beetle larvae (Shaw 1990). Southeast Asia is a key area to understanding the complicated evolutionary history of the family Megalyridae because the sister-group pairs of both Ettchellsia (Dinapsis Waterson: Afrotropical) and Carminator (Cryptalyra Shaw: Neotropical) occur in far separated areas (Shaw 1990;Vilhelmsen et al. 2010). Further findings from Southeast Asia will help the understanding of the evolutionary history of the Megalyridae.

Materials and methods
The morphological terms used in the descriptions follow Shaw and van Noort (2009) and Vilhelmsen et al. (2010). Photo images were produced using Leica Application Suite (Leica Microsystems) and Combine ZM software (Alan Hadley, www.hadleyweb. pwp.blueyonder.co.uk). Line drawings were made using a drawing tube attached to a binocular microscope. The depositories of the types are as referenced after the collection data.

Key to the females of the species of Ettchellsia
Fore wing (Fig. 1) bearing four transverse dark bands; vein M 1.9 × basal part of RS; erect setae on C 0.2 × those on Sc+R and A.
Color. Head black; mandible black; antenna brown-black except scape and pedicel brownish; long setae on vertex and gena black, other setae white. Mesosoma black except brown tegula; long erect setae black; fore-and middle legs brown; hind leg with coxa, distal half of femur and distal four tarsomeres brown-black, trochanter and basal part of femur brown, tibia and basitarsus black; long setae on dorsal surface of hind tibia and basitarsus black. Metasoma and ovipositor reddish brown; ovipositor sheath pale brown.
Distribution. Peninsular Malaysia; Borneo. Etymology. This species is named for the reddish coloration of the metasoma. Remarks. This species is similar to E. sinica with both having a strongly humped mesoscutum, however, it is distinguished from the latter by the strongly narrowed median region of propodeum (Fig. 12); long erect black setae on hind tibia and basitarsus, many of which are longer than the width of the hind tibia (setae are whitish and shorter in E. sinica); reddish brown metasoma (Fig. 1) (metasoma is black in E. sinica). Mesosoma (Fig. 6) entirely covered with short decumbent setae, but long erect setae also present on mesonotum; mesoscutum smooth except lateral carina present on anterior surface; dorsal mesoscutal surface not humped; axilla and scutellum smooth; metanotum setose; propodeum (Figs. 13) with pair of median, submedian and lateral carinae; median region narrowed anteriorly, with eight indistinct transverse carinae, posterior margin posteriorly produced; submedian propodeal region converging posteriorly, with two transverse carinae excluding posterior areola; lateral region with two (right side) or four (left side) transverse carinae.

Ettchellsia nigripes
Fore wing (Fig. 4) bearing four transverse dark bands but separation between second and third bands indistinct; vein M 2.2 × basal part of RS; erect setae on C 1.2 × longer than those on Sc+R, equal to those on vein A.
Color. Body entirely black except tarsi and ovipositor sheath dark brown, ovipositor reddish brown; long setae on vertex, gena, mesonotum and dorsal surface of hind tibia and basitarsus black, other setae white.
(Male) Unknown. Distribution. Sulawesi Island. Etymology. This species is named for its black legs. Remarks. This species is similar to E. reidi Mita & Shaw, sp. n. by the almost flat mesoscutum, however, it is distinguished from the latter by the anteriorly weakly narrowed median region of propodeum (Fig. 13) and the mostly smooth surface between posterior ocellus and eye (Fig. 5).
surface; dorsal surface not swollen; axilla and scutellum smooth; metanotum setose; propodeum ( Fig. 14) with pair of median, submedian and lateral carinae; median propodeal region narrower centrally, with a few transverse carinae in holotype, carinae indistinct in a paratype; posterior margin dorsally producing; submedian region smooth excluding posterior areola, parallel-sided; lateral region with at most four transverse carinae but keels sometimes indistinct.
Fore wing (Fig. 7) bearing three transverse dark bands with clear spot around Rs+M; vein M 1.6-1.7 × basal part of RS; erect setae on C 2.0 × those on Sc+R, 1.2 × those on A.
Color. Head black; mandible dark brown; antenna dark brown except scape, pedicel and 5-8th flagellomeres brown; long setae on vertex, gena black. Mesosoma black; long setae on mesonotum black; legs black except tarsi brownish; long setae on dorsal surface of hind tibia and basitarsus black. Metasoma brownish black; ovipositor and ovipositor sheath dark brown.
(Male) Unknown. Distribution. Kalimantan Barat, Borneo. Etymology. The species name is dedicated to the collector of the types, Chris Reid, a coleopterist working at the Australian Museum, Sydney.
Remarks. The specimens were collected as part of the Insects of Indonesia Project, a collaboration of the ROM with the MZB. This species is similar to E. nigripes Mita & Shaw, sp. n. About identification of the two species, see the remarks of E. nigripes.