ON A COLLECTION OF CHALCIDOIDEA ( HYMENOPTERA : INSECTA ) FROM THE MANGROVE ECOSYSTEMS OF KERALA , SOUTH INDIA WITH THE DESCRIPTION OF A NEW SPECIES

Entomofauna associated with the mangroves is poorly known. The order Hymenoptera (Insecta) of the mangrove ecosystem is represented by the pollinator, predator, phytophagous and parasitic species. Among the parasitic Hymenoptera Chalcidoidea represents an economically important group, members of which are mostly parasitic on other insects, thus playing a vital role in the natural regulation of insect population. The present account is based on the study of a small collection of Chalcidoidea from the mangrove and associated vegetations from North Kerala with Zoological Survey of India, Western Ghats Field Research Station, Calicut. Eleven species of Chalcidoidea belonging to 3 families are reported here for the first time from the mangrove ecosystem. The account also includes description of a new chalcid species belonging to the family Eurytomidae viz. Tetramesa calicutensis Spa nov. The specimens were identified following Narendran (1989, 1994) and Sureshan 2003. Terminology in this paper follows to that of Boucek (1988). Following abbreviations are also used.


INTRODUCTION
Entomofauna associated with the mangroves is poorly known.The order Hymenoptera (Insecta) of the mangrove ecosystem is represented by the pollinator, predator, phytophagous and parasitic species.Among the parasitic Hymenoptera Chalcidoidea represents an economically important group, members of which are mostly parasitic on other insects, thus playing a vital role in the natural regulation of insect population.The present account is based on the study of a small collection of Chalcidoidea from the mangrove and associated vegetations from North Kerala with Zoological Survey of India, Western Ghats Field Research Station, Calicut.Eleven species of Chalcidoidea belonging to 3 families are reported here for the first time from the mangrove ecosystem.The account also includes description of a new chalcid species belonging to the family Eurytomidae viz.Tetramesa calicutensis Spa nov.The specimens were identified following Narendran (1989Narendran ( , 1994) ) and Sureshan 2003.Terminology in this paper follows to that of Boucek (1988).Following abbreviations are also used.Diagnostic characters : Length 1.5 mm.Head and thorax shiny black, gaster shiny purple violet, antennae brown.Head very slightly wider than thorax; antennae with scape slender, as long as the funicular segments combined; FI shortest, F3-F5 gradually becoming thicker; thorax delicately reticulate; gaster almost as long as thorax, with a small tuft of white setae at base on either side of petiole.
Remarks : Common species.Diagnostic characters : Length 2.5 mm.Black, antenna brownish black; antenna with scape just reaching level of front ocellus; propodeum with its median part broadly concave with shallow depression containing microsculptures and some vertical irregular rugae; gaster with petiole as long as broad, distinctly longer than head plus thorax combined.
Head: Unifonnly and finely reticulate, meshes very small, with long white hairs; gena almost shiny, malar grooves weakly indicated; clypeal area slightly raised, anterior margin angularly produced.Head in dorsal view 1.6x as wide as long; temple length O.43x eye length; POL 2x OOL.In front view head width 1.2x height; eye length 1.23x width in profile; malar space O.46x eye length; scrobe deep, not reaching median ocellus.Antennae (Fig. 1) inserted above lower margin of eyes; scape hardly reaching median ocellus, finely reticulate, length O.7x eye length; pedicel plus flagellum length as long as head width; antennal fonnula 11153; pedicel as long as Fl and as wide as F5; F2-F5 equal in length, shorter than Fl; funicular segments longer than wide, except F5 almost subquadrate, club as long as 3 preceding segments combined; funicular segments covered with long setae.Thorax: 2.3x as long as wide, pronotum almost as long as wide, collar ecarinate, finely reticulate.Mesoscutum medially shorter than pronotum and I.6x as wide as long, notauli complete, deep and groove like.Scutellum similarly reticuate as on mesoscutum and pronotum, medially little longer than mesoscutum.Propodeum (Fig. 2) lies at 4So to longitudinal line of mesoscutum, convex, uniformly reticulate punctate, meshes small, medially 0.7x as long as scutellum, medially with a shallow fovea, basal part with few short carinulae separated by deep foveae, only upper part of callus covered with white hairs.Prepectus finely reticulate.Mesopleuron with mesepisternum moderately reticulate, mesepimeron transversely striated.Metapleuron similarly reticulate as on propodeum.Forewing length 2.7x width, basal part with less pubescence, speculum open below, PMV short, stigma slightly enlarged.Relative lengths of SMV 33, MV 12, PMV 6, STY 4. Hind coxae finely reticulate, femur finely and longitudinally striated.Relative lengths of hind coxa 12, femur 20, tibia 26, tarsus 24.
Male: Length 2.2 mm.Similar to female but differs in having antennal scape swollen (Fig. 3), funicular segments pedunculate with whorls of long hairs; gaster petiolate, short, only 0.72x as long as head plus thorax combined.

Etymology:
The species is named after the type locality.
Remarks : Among the species with S segmented funicle and pronotum (including column) distinctly longer than mesoscutum, T. calicutensis sp.nov.resembles T. distincta Narandran and T. narendrani Sureshan (Sureshan, 2004) and runs to couplet S of the key to Indian species of Tetramesa (Narendran, 1994).But it differs from T. distincta in having forewing with MV 2x PMV, POL 2x OOL, gaster as long as head plus thorax combined, shorter antennae, and genal area almost smooth with very fine reticulation.(in distincta MV 1.65x PMV, POL 1.46x OOL, gaster little longer than head plus thorax combined, longer antennae and genal area distinctly striated).It differs from T. narendrani in having smaller size, genal area smooth, POL 2x OOL, antennae with FI as long as pedicel, pedicel plus flagellum as long as head width, thorax with small meshed reticulation, pronotum almost as long as broad, propodeum with small meshed reticulation and covered with hairs only on upper callus, forewing with MV 2x PMV and gaster as long as head plus thorax combined with T4 little longer than T3.(in narendrani body size larger, genal area striate, POL 1.3x OOL, FI longer than pedicel, pedicel plus flagellum 1.3x as long as head width, thorax with broad meshed reticulation, pronotum width 1.3x median length, MV 1.6x PMV; propodeum with broad meshed reticulation and whole surface covered with white hairs, gaster 1.3x as long as head plus thorax combined with T4 distinctly longer than T3).

DISCUSSION
Eleven species of Chalcidoidea (Hymenoptera: Insecta) belonging to 10 genera and 3 families are reported for the first time from the mangrove ecosystems of Kerala, South India.One species belonging to the family Eurytomidae viz.Tetramesa calicutensis is described new to science.
Length 5-7 mm.Black, hind femur black with apex yellow; hind tibia yellow with base black; head not wider than thorax, with fine and close punctuation, preorbital carina absent, post orbital carina reaching posterior margin of genotemporal region; hind coxa with a distinct ventromesal tooth; apex of scutellum weakly emarginated; gaster oval, short, Tl smooth.
1924.Diagnostic characters : Length 2.5-3 mm.Body metallic blue with bronzy patches; antennae yellowish brown; anterior margin of clypeus almost straight; antennae with third anellus as long as first and second combined; propodeum with moderate nucha, plicae strong; forewing with PMV as long as or little longer than MV; gaster cordifonn.