Ichneumonid wasps from Madagascar . VI . The genus Pristomerus ( Hymenoptera : Ichneumonidae : Cremastinae )

1 Iziko South African Museum, Natural History Department, PO Box 61, Cape Town 8000, South Africa; Stellenbosch University, Department of Botany and Zoology, Evolutionary Genomics Group, Private Bag X1, Stellenbosch 7602, South Africa E-mail: rousse.pascal@wanadoo.fr (corresponding author) 2 Muséum National d’Histoire Naturelle, Dépt. Systématique & Evolution, UMR7205 MNHN–CNRS, CP50, 45 rue Buffon, 75005 Paris, France E-mail: villeman@mnhn.fr † Deceased author


Introduction
Madagascar and the nearby islands of the Western Indian Ocean have been classified as a "Biodiversity hotspot" (Myers et al. 2000). Its endemism rate is exceptionally high (Goodman & Benstead 2003) and it remains one of the least investigated biogeographic areas on the planet. It is unfortunately also characterized by a rapid loss of natural habitats, mainly due to large-scale deforestation. The inventory of Malagasy biodiversity is therefore a priority for conservation purposes. André Seyrig (1897Seyrig ( -1945 was a pioneer by collecting and inventorying the local entomofauna. He mainly focused on the huge The key provided allows for the identification of these species. The reader may also refer to Table  1, though correct identification of isolated male specimens of this genus may be not achievable. The species are presented in alphabetical order and new taxa are described. The examined specimens were collected by A. Seyrig unless otherwise stated. Except for P. keyka sp. nov. and P. ranomafana sp. nov. (deposited in the CAS collection), all holotypes are housed in the MNHN collection.

Taxonomic descriptions
Phylum Arthropoda Latreille, 1829 Class Insecta Linnaeus, 1758 Order Hymenoptera Linnaeus, 1758 Family Ichneumonidae Latreille, 1802 Subfamily Cremastinae Förster, 1869 Genus Pristomerus Curtis, 1836(definition after Townes 1971 Diagnosis Body moderately slender, metasoma moderately to strongly compressed. Occipital carina usually complete. Females (often) and males (nearly always) with hind femur swollen and bearing a tooth on lower side. Forewing with areolet open (3rs-m absent), vein Rs&M opposite or a little basal to vein cu-a, and 2rs-m basal to 2m-cu by at least 2rs-m length. Hindwing with vein Cu1 spectral. Tergite 1 moderately slender, glymma hardly distinct. Lower edges of tergite 1 separated and parallel. Epipleura of tergite 2 narrow, separated by a crease and turned under. Thyridium present, transverse or subcircular, located in basal 0.2 of tergite 2. Ovipositor tip most often sinuate. Apex of male gonosquama rounded.

Diagnosis
Small species; face pale yellow; head and mesosoma pale yellow with brown markings, metasoma dark brown, tergite 4 and following lighter, more or less yellow maculated; head strongly constricted behind eyes; face transverse and ventrally narrowed, densely punctate, clypeus smooth, narrow, convex in profile; mesoscutum densely punctate, scutellum moderately punctate with posterior face striate; area superomedia about 2 x longer than wide; female femoral tooth small, sometimes reduced to a small angulation; ovipositor moderately short, its tip straight; POL 1.9; OOL 1.1; CT 1.4; ML 0.5; OT 1.3; FFT 1.

Differential diagnosis
Closely related to P. moramora, but readily distinguishable by the straight tip of ovipositor, the transverse head and the relatively narrow clypeus.

Etymology
Euphonic arrangement of letters.
CoLor. Antenna brown, scape and pedicel ventrally orange. Head and mesosoma yellow with dark maculae. Dark brown to brown: frons, vertex, lobes of mesonotum, a transverse spot on mesopleuron and metapleuron, scuto-scutellar groove, apex of scutellum and post-scutellum, metanotum and median basal half of propodeum (in some individuals, the dark marking is faded on pleurae, scutellum and propodeum). Legs yellow, front and mid coxae and all trochanters white, hind leg more orange with tarsus and tibia basally and apically infuscate; dorsal margin of hind tibia white. Wings hyaline, pterostigma light brown. Metasoma brown, tergites 1-3 dark brown, their apex more or less bordered with yellow, lateral margins of tergite 2 sometimes bordered with yellow, other tergites brown orange. Thyridia yellow. Ovipositor sheath brown.

Remarks
The straight ovipositor is a very rare feature in Pristomerus spp. mentioned by Townes (1971) in only one undescribed Afrotropical species. Fitton, 1994 Fig. 4

Differential diagnosis
Closely related to P. vahaza. Both share the same color pattern but may be distinguished by the shape of mesosoma, distinctly elongate in P. vahaza, and by the scutellum which is flat in P. vahaza and convex in P. caris.

Remarks
The large series of specimens available in Seyrig's collection shows considerable variation with respect to the description of P. caris by Polaszek et al. (1994). The propodeum carination is highly variable, with area basalis petiolate to truncate, and area superomedia which greatly varies in length. Color also varies from lighter specimens with reduced brownish markings to darker ones with larger black spots on face, vertex, mesoscutum and propodeum. We furthermore observed two male groups with differently sized ocelli (Fig. 4C, D). Such variability is however not correlated with any other plastic or geographical difference. These specimens might represent a species complex whose study needs more comprehensive molecular and morphometric investigations. Tosquinet, 1896 Fig. 5

Differential diagnosis
Species recognizable by the combination of the color pattern and the almost smooth mesoscutum of male.

Host records
Five specimens collected by B. Sigwald in 1962 emerged from lycaenid cocoons on Crotalaria sp. (Leguminosae); three of these cocoons have been found inside pods (new host record).

Remarks
This species exhibits a moderate variability in the color pattern, especially on the extension of the dark markings on mesosoma and metasoma. The specimens from Madagascar are noticeably lighter than those from mainland Africa, especially Namibia.

Distribution
Madagascar (Toliara and Toamasina province) (new distribution record). Mozambique and Senegal.

Differential diagnosis
Species characterized by the black and white color pattern of metasoma, and the entirely densely punctate-granulate mesosoma.

Etymology
Refers to a great beer of similar color pattern.
MesosoMa. Moderately elongate, nearly 2 x longer than high. Pronotum, mesonotum, mesopleuron and metapleuron densely punctate-granulate. Speculum punctate with a narrow smooth ventral area. Notaulus strongly impressed. Propodeum long, densely punctate, area petiolaris transversally wrinkled, area basalis opposite or slightly truncate, area superomedia about 2.5 x longer than wide, about as long as area petiolaris. Legs: femoral tooth reduced but distinct, followed by a row of small tubercles.
CoLor. Head ivory white with frons, vertex, temple, occiput, posterior half of gena, and a small triangle under toruli black. Antenna basally black, fading to testaceous from flagellomere 3 but two apical flagellomeres darker. Mesosoma and legs testaceous orange. Metasoma black, tergites 2 and following largely white apically. Wings hyaline, densely hairy, pterostigma dark brown.

Differential diagnosis
Species closely related to P. caris, from which it differs by the characters given in the key; the ovipositor is strikingly longer than in any other Pristomerus species in Madagascar.

Etymology
Dedicated to Ace Hanson.
CoLor. Orange overall with flagellum and ovipositor sheath brownish. Head ivory white with frons centrally, vertex and occiput dark brown. Wings hyaline, pterostigma orange.

Differential diagnosis
The combination of small size, orange face, absence of femoral tooth in female and hardly enlarged ocelli in male makes this species readily distinguishable from any other in Madagascar but P. moramora. Both may be differentiated by characters given in the key.

Etymology
Euphonic reference to the small size of this species: "kely" is the Malagasy word for "little".

Differential diagnosis
Species mainly characterized by the quite short antennae with 23 flagellomeres and the very weak microsculpture.

Etymology
Euphonic arrangement of letters.

Male
Unknown.

Differential diagnosis
Species highly characteristic on account of the head color, the relatively short ovipositor and the laterally not delimited area superomedia.

Etymology
Euphonic arrangement of letters.
MetasoMa. Tergites 1 almost smooth, post-petiole and tergite 2 finely aciculate. Tergite 2 almost as long as tergite 1 and about 2 x longer than apically wide. Ovipositor relatively short, slightly up-curved and briefly sinuate at apex.
CoLor. Head blackish brown with clypeus, malar space and mandible pale yellow. Mandibular teeth and antennae dark brown. Mesosoma testaceous-orange, dorso-laterally slightly infuscate. First tergite blackish. Second tergite with basal half yellow, apical half black with a yellow margin. Remainder of metasoma testaceous-orange. Legs orange, hind tibia (basally) and hind tarsus darker. Wings hyaline, pterostigma and ovipositor sheath dark brown.

Etymology
"Mora mora" is an indispensable expression in Madagascar meaning "take it easy".
CoLor. Antenna brown, scape and pedicel orange ventrally. Head and mesosoma yellowish-orange with more or less extended brown markings. Face, inner orbits and gena yellow. Brown: frons, ocellar triangle, lobes of mesonotum, a large macula on mesopleuron and metapleuron, scuto-scutellar groove, dorsal face (and sometimes lateral margins) of scutellum, basal part of propodeum, including entire area superomedia and areae dentiparae. In some individuals, the median lobe of mesoscutum, and the scutellum are light brown. Legs yellowish-orange, front and mid trochanters white. Hind leg with coxa, femur, basal and apical margins of tibia, and tarsus infuscate, hind tibia mid-dorsally white. Wings hyaline, pterostigma brown. Metasoma brown, base of tergite 1 orange, post-petiole and other tergites dorsally dark brown and more or less marked with orange posteriorly. Thyridia yellow. Ovipositor sheath brown. Length: 3.1 (2.6-3.5) (6 specimens). Posterior ocelli equally distant from each other as from eye (POL = OOL = 1.0). Face not narrowed ventrally. Hind femur swollen, femoral tooth long, followed by a row of denticles. Otherwise similar to female.

Remarks
Five specimens (4 ♀♀, 1 ♂) with a larger (L: 3.7-3.9) and lighter body have been related to P. moramora but not included in the type series: they have identical ocellar indices, the same number of flagellomeres and a similar microsculpture; however, the base of petiole is yellow, the mesosoma and metasoma from the fourth tergite are entirely orange, and the ovipositor is longer (OT = 1.9-2), perhaps due to allometry.

Differential diagnosis
Species closely related to P. roberti, characterized by the dense punctation of face, the propodeum with area superomedia hardly delimited laterally and the almost smooth second metasomal tergite.

Etymology
Euphonic arrangement of letters.

Differential diagnosis
Species superficially close to P. caris and related species with white face, distinguishable by the dark color pattern, the longer ovipositor and the very short vein 2rs-m.
MesosoMa. Moderately elongate, 1.8 x longer than high. Mesoscutum and pleurae densely punctategranulate anteriorly, smoother posteriorly. Pronotum almost smooth centrally, epomia distinct. Scutellum smooth with some punctures. Speculum almost smooth. Propodeum shining, densely punctate. Area basalis opposite, area superomedia 2 x as long as wide. Propodeum, pleurae and ventral margin of coxae covered with white hairs. Wings: fore wing with vein 2rs-m very short, about 0.3 x as long as 2m-cu, and basal to 2m-cu by 4 x its length. Legs: long and thin, without a distinct tooth on hind femur.
CoLor. Head ivory white with black markings. Black: antennae, center of face and frons, vertex, occiput, posterior half of outer orbit and a dorsal spot crossing the orbit. Mesosoma rufo-testaceous with black marking on median lobe of mesoscutum, scuto-scutellar groove, lateral sides of scutellum, post-scutellum and dorsal face of propodeum. Metasoma orange brown. Tergite 1 basally and laterally yellow. Postpetiole and tergite 2 black, the following tergites dorsally brown. Fore and mid legs pale brown with femora slightly darker. Hind legs blackish-brown, tibia slightly paler. Wings hyaline, pterostigma dark brown. Ovipositor sheath dark brown.

Male
Unknown.

Differential diagnosis
Species closely related to P. cunctator, distinguishable by the color pattern and the longer ovipositor. The mesonotum of P. roberti is uniformly orange, without any yellowish orange markings on notauli and scutellum.

Etymology
Named for Thierry Robert, entomologist at the Office National des Forêts.

Differential diagnosis
Species superficially close to P. caris and related species with white face. Pristomerus vahaza sp. nov. may be distinguished by the combination of an elongate mesosoma, a brown pterostigma and a relatively short ovipositor. The lateral ocellus in male is distinctly more distant from eye margins (OOL = 0.6) than in P. hansoni sp. nov. and P. caris (OOL = 0.2).

Etymology
Refers to the white face: "vahaza" is the Malagasy word for pale foreigners.
CoLor. Orange. Head ivory white with antennae, center of frons, vertex and occiput black. A pair of black spots across outer orbits dorsally. Face with a small median brown spot below toruli. Tergites 1-3 infuscate. Ovipositor sheath black. Wings hyaline, pterostigma testaceous.

Differential diagnosis
Species characterized by the unusual color pattern and the strong femoral tooth of female.
MetasoMa. Post-petiole, tergite 2 and base of tergite 3 finely aciculate, the following tergites granulate. Tergite 2 about half as long as tergite 1 and about 1.5 x longer than apically wide. Thyridia transverse and oval. Ovipositor thin and moderately long, its apex slightly sinuate.

Remarks
The three specimens from South Africa have the head differently colored, with face blackish, and mandible and orbits yellow. Furthermore, the dorsal edge of clypeus is densely punctate. They are otherwise strictly similar to the holotype and are included as non-type specimens.

Differential diagnosis
Species characterized by the weakly sculptured mesosoma with smooth area superomedia and the strong femoral tooth of female. The male coloration is similar to that of P. veloma which is bigger and has a punctate-granulate mesosoma.

Etymology
Euphonic arrangement of letters.
MesosoMa. Slightly elongate, about 1.7 x longer than high. Mesoscutum finely granulate with sparse punctures, posteriorly smoother. Scuto-scutellar groove striate, scutellum smooth. Mesopleuron shining and sparsely punctate, metapleuron moderately punctate-granulate. Propodeum with strong carination, area basalis opposite or slightly petiolate, area superomedia almost smooth, 2 x as long as wide, area petiolaris with transverse wrinkles. Hind femur slightly swollen, with an acute tooth followed by a series of very small denticles.

Male
Length: 5.1 (4.8-5.5) (10 specimens). Eyes strongly convergent dorsally. Posterior ocelli widely separated (POL = 1) and very close to eyes (OOL = 0.2). Hind femur strongly swollen with a sharp tooth followed by a dense row of more or less merging fine denticles. Thyridia slightly elongate, oval. Metasoma entirely dark brown. Base of hind tibia darker. Otherwise similar to female.

Discussion
The newly described Pristomerus fauna in Madagascar could be compared to a large body of undetermined material housed at ISAM. This latter material contains hundreds of individuals, collected throughout Sub-Saharan Africa since the beginning of the last century (especially over the last 20 years) and until now Pristomerus has not been identified to species level. This examination led to the description of numerous new species (see also Rousse & van Noort, in prep.) and also enabled us to get a first assessment of the relationships of the Pristomerus fauna between Madagascar and mainland Africa.
Firstly, we did not find any white-faced species outside of Madagascar, where this color pattern appears to be rather common. Five closely related species (P. caris sp. nov., P. guinness sp. nov., P. hansoni sp. nov., P. ranomafana sp. nov. and P. vahaza sp. nov.) thus share a habitus restricted to the island, most likely representing a local diversification. This is further supported by the large internal variation noticed in the probable P. caris species-complex.
Secondly, only three of the 15 species are found outside of Madagascar, namely P. cunctator, P. albescens and P. veloma sp. nov., which are also present on the Eastern African coast. No relation could be found with the known Indian fauna. This suggests both an African origin and a high endemism rate for the Malagasy fauna. Such results are far from unexpected, agreeing with the usual endemism rates reported there (Goodman & Benstead 2003) and in previous analyses of the Malagasy ichneumonid fauna (Seyrig 1932;Heinrich 1938). The genus Enicospilus (Ophioninae) is also very diverse in Afrotropics: Gauld & Michell (1978) reported 84 species in Madagascar, of which 39 occur on mainland Africa as well. In addition, five Enicospilus species are also present in the Oriental Region, particularly on the