A review of the genus Platecrizotes Ferrière (Hymenoptera: Chalcidoidea: Pteromalidae) with the description of a new species from India

Acknowledgements: The authors are grateful to Dr.Kailash Chandra, Director, Zoological Survey of India, Kolkata for providing facilities and encouragement. PMS and KN are grateful to the Ministry of Environment , Forests and Climate change, Govt. of India for funding the research on Indian Pteromalidae through the AICOPTAX project. VKRF is grateful to the University Grants Commission, New Delhi for award of Moulana Azad Fellowship for minority students to pursue Ph.D. degree. The genus Platecrizotes Ferrière, 1934 (Type species P. sudanensis Ferrière) belongs to the subfamily Pteromalinae of Pteromalidae (Hymenoptera: Chalcidoidea) and is currently known by three species worldwide. Ferrière (1934) placed this genus in the subfamily Pireninae. Bouček (1964) noted the close affinity of Platecrizotes with Pachycrepoideus Ashmead, and considered the former genus as a member of the subfamily Pteromalinae. The three species are: P. sudanensis Ferrière (North and South Africa, Sudan, Senegal, Zimbabwe and Nigeria), P. argentinensis De Santis (Argentina) and P. europaeus Bouček (Moldova and Poland). Except for an undescribed species reported by Bouček et al. (1979) from Tamil Nadu (India), the genus is not yet reported from the Oriental region (Noyes 2014). While studying the host parasitoid associations of Pteromalidae in the agro ecosystems of Kerala (India), we reared adult parasitoids from the pupa of an unidentified dipterous genus near Drosophila. These pupae were found inside the putrefied fruits of bitter gourd (Momordica charantia Linnaeus) from which adult drosophilid flies also emerged. On detailed examination, these parasitoids proved to belong to an unreported species of Platecrizotes, which is described below. This is the first description of a species of Platecrizotes from the Oriental region. A diagnosis of the genus and systematic account on the species of Platecrizotes, and a key to the identification of the four species are also provided.

The genus Platecrizotes Ferrière, 1934 (Type species P. sudanensis Ferrière) belongs to the subfamily Pteromalinae of Pteromalidae (Hymenoptera: Chalcidoidea) and is currently known by three species worldwide. Ferrière (1934) placed this genus in the subfamily Pireninae. Bouček (1964) noted the close affinity of Platecrizotes with Pachycrepoideus Ashmead, and considered the former genus as a member of the subfamily Pteromalinae. The three species are: P. sudanensis Ferrière (North and South Africa, Sudan, Senegal, Zimbabwe and Nigeria), P. argentinensis De Santis (Argentina) and P. europaeus Bouček (Moldova and Poland). Except for an undescribed species reported by Bouček et al. (1979) from Tamil Nadu (India), the genus is not yet reported from the Oriental region (Noyes 2014).
While studying the host parasitoid associations of Pteromalidae in the agro ecosystems of Kerala (India), we reared adult parasitoids from the pupa of an unidentified dipterous genus near Drosophila. These pupae were found inside the putrefied fruits of bitter gourd (Momordica charantia Linnaeus) from which adult drosophilid flies also emerged. On detailed examination, these parasitoids proved to belong to an unreported species of Platecrizotes, which is described below. This is the first description of a species of Platecrizotes from the Oriental region. A diagnosis of the genus and systematic account on the species of Platecrizotes, and a key to the identification of the four species are also provided.

Material and Methods
The study is based on the specimens reared from the host infested plant material, putrefied fruits of bitter gourd collected from the cultivations of mixed vegetables form Vengeri, Kozhikode District, Kerala (11.3044 0 N & 75.7967 0 E).
The fruits contained unknown dipterous pupae, which are very near to the genus Drosophila, from which the adult parasitoids emerged. The emerged parasitoids were preserved in 70% ethyl alcohol and card-mounted for microscopic observation. The specimens were studied under a stereoscopic binocular microscope (Leica MZ16) and a forewing was removed from a paratype and mounted on a glass slide using Canada balsam. Photographs were taken with a Scanning Electron Microscope (Model JEOL Neoscope JCM-5000) and line drawings were prepared with a camera Lucida of Leica MZ16 microscope. The terminology used in the paper follows Gibson (1997).
Metasoma petiolate, petiole punctate, covered ventrally by the extension of first gastral sternite; T1 occupying about one-third to almost half of gaster, its hind margin broadly round or angularly produced and emarginated sub-laterally, T2 shorter than T1 but as long as T3 and T4 combined. Ovipositor sometimes strongly protruded beyond apex of gaster. In male, gastral tergites beyond T1 strongly retracted.
Distribution: Palaearctic, Afrotropical, Oriental and Neotropical regions of the world.

Etymology
The species is named after Kerala State (India) from which collections were made.
Colour: Body black. Head with eye and ocelli silvery. Antenna brownish black except scape, pedicel and anelli testaceous, upper part of pedicel more blackish, pubescence white. Tegula brown. Wings hyaline, veins and pubescence brown. Legs with coxae black, all femora dark brown, trochanters, tibiae and tarsi except tips testaceous, tips of tarsi brown. Ovipositor yellow.
Head (Image 1): sub prognathous, uniformly and moderately reticulate, with small white pubescence; reticulation on occipital area finer with meshes broad; head, in dorsal view, width 1.72× length; POL 1.3× OOL; head, in front view, 1.2×as wide as long; clypeus angularly produced, medially raised, defined at sides by incisions in mouth margin; antennal torulus (Image 1) separated by three diameter of it from lower margin of head; eye length 1.5× width in profile; malar space 0.4× eye length; malar sulcus less distinct; temple length 0.34× eye length; eyes with small pubescence. Antenna (Image 2) with scape 1.9× as long as eye, almost of uniform width, as long as funicle plus anelli, first and second anellus very thin, third a little wider; clava not distinctly separated from funicle, as long as 2.5 preceding segments combined; all funicular segments with one row of long sensillae. Mesosoma (Image 3): Pronotal collar broad, anteriorly round, width 5× median length, distinctly reticulate, meshes broad. Mesoscutum 2.5× as broad as median length, distinctly reticulate, meshes not broad as on pronotum, notauli complete, deep in the anterior part, less distinct towards posterior end. Scutellum 1.1× as broad as long, reticulation uniform and longitudinal, with a narrow smooth line in the middle, which is less distinct in paratypes examined. Axilla similarly reticulate as on scutellum. Dorsellum narrow and shiny. Propodeum 2× as broad as median length, uniformly reticulate, reticulation on median area broad, callus with small hairs; plicae distinct, almost reaching base of well-defined nucha; spiracles elongated, oval, almost touching hind margin of metanotum. Prepectus broad, distinctly reticulate. Mesopleuron uniformly reticulate, but reticulation finer on upper mesepimeron; sub-alar area transversely reticulate; metapleuron distinctly reticulate. Forewing (Fig.1) length 2.21× width; discal pubescence sparse but distinct; marginal fringe long; basal cell closed below, sparsely hairy; speculum open below extending almost up to middle of MV; stigma moderately capitate; marginal vein moderately widened at base. Hind coxa distinctly reticulate with tuft of hairs postero-laterally; hind tibia with two unequal spurs.
Metasoma (Image 4): Gaster distinctly petiolate, petiole elongate, 2.5× as long as broad, finely but distinctly reticulate with a faint median keel, covered ventrally by the extension of first sternite up to threefourths its length; 1.53× as long as broad in dorsal view; posterior margin of T1 angulate and sinuate on either side laterally; T2 0.4× as long as T1; T3,T4 and T5 subequal in length; ovipositor distinctly exserted in the holotype, length of exserted part 0.42x total length of gaster, but in all paratypes ovipositor not exserted.
Male: Length, 1.34mm. Resembles female, but differs from it in having antenna (Fig. 2) with two anelli and 6 funicular segments, second anellus thick; F1 smaller than other funicular segments, pubescence longer; gaster short, compressed and tergites beyond T2 retracted, hind margin of T1 not much angularly produced as in female (Fig. 3).
Host: Reared from dipterous pupa (near Drosophila sp.) breeding in putrefied fruits of bitter gourd, probably parasitic in the pupae.
Discussion: This new species closely resembles P. europaeus in general morphology, body sculpture, pubescence and especially in the nature of antennal insertion which is just below the ocular line separated by three diameters of antennal torulus from mouth margin, nature of wings and antennae, but differs from it in having: antenna with clava 2.5× as long as preceding segments combined, with colour of scape, pedicel and anelli testaceous; clypeus angularly produced; scutellum disc not smooth and shiny; propodeum with plicae distinct, reaching up to base of nucha; wings hyaline; gastral petiole long, 2.5× as long as broad with a median keel; and T1 of gaster not reaching up to middle. In P. europaeus: antenna with clava as long as three preceding segments combined and uniformly black; clypeus roundly produced; scutellum disc smooth and shiny; propodeum without plicae; wings subhyaline; gastral petiole slightly transverse without median keel; and T1 reaching almost up to middle. In the nature of gaster, and antenna the new species also resembles P. sudanensis, but in sudanensis antenna is inserted far below lower ocular line separated by only one diameter of the antennal torulus from the mouth margin and forewing with MV abruptly swollen in basal half. The other species of the genus P. argentinensis differs from the new species in having a rather straight MV, mesoscutum with notauli incomplete, forewing without marginal fringe and propodeum with a weak median carina. Diagnosis: (Based on the description by Boucek, 1951) Female. Antenna inserted below eye margin, toruli separated by one diameter of it from the mouth margin; clypeus sub truncate; both mandibles 4-toothed. Pronotum with collar angularly (not sharply) set off; mesoscutum with notauli indistinct; propodeum large, horizontal, median carina vaguely indicated, plicae indicated anteriorly by smooth streaks; propleuron strongly shifted forward, well visible from above. Forewing with SMV abruptly swollen in basal half, slender in the apical part, about twice as long as STV; basal fold with several hairs; cubital fold nearly bare; speculum extended below MV up to STV. Metasoma with petiole nearly twice as long as broad; gaster flat, oval-pointed, broader and shorter than mesosoma; T1 occupying about one-third of gaster.

Platecrizotes sudanensis
Material examined: Nil. Distribution: North and South Africa, Sudan, Senegal, Zimbabwe and Nigeria.