Description of a new species of Eubroncus Yoshimoto (Hymenoptera: Mymaridae) from India, with a key to world species

Genus Eubroncus was erected by Yoshimoto et al. (1972) under the subfamily Eubroncinae, that includes two genera, Eubroncus Yoshimoto, Kozlov & Trjapitzin and Stomarotrum Yoshimoto, Kozlov & Trjapitzin, based on prominent mandibles that were almost as long as the head height. Eubroncus was erected with E. orientalis Yoshimoto, Kozlov & Trjapitzin (male) as the type species from Malaysia, and Stomarotrum with S. prodigiosum Yoshimoto, Kozlov & Trjapitzin (female) from the Russian Far East. Later Triapitsyn & Huber (2000) synonymized Stomarotrum with Eubroncus. Triapitsyn & Berezovskiy (2002) redescribed E. prodigiosus (Yoshimoto, Kozlov & Trjapitzin) and keyed males of the two known species based on color of mesosoma and whether the pronotum is divided or not. Viggiani (2003) described the male genitalia of E. prodigiosus from Japan. Lin et al. (2007) recorded an unidentified species from Australia. Hayat & Khan (2009) described the third species, E. indicus Hayat & Khan, from a single female from India. Jin & Li (2014) described three additional species, E. vertexus Jin & Li, E. bani Jin & Li and E. tibetanus Jin & Li, from China. Here we describe the second species from India and seventh from the world.


Materials and Methods
Collections were made using yellow pan traps as described by Noyes (1982) from sandalwood forest area of Institute of Wood Science and Technology (IWST), Bengaluru, Karnataka and Oilpalm ecosystem, Mulakadu, Kallakuruchi Taluk of Tamil Nadu. Specimens were processed using hexamethyldisilazane as described by Brown (1993) and either card, point or slide mounted, labeled and studied. All specimens are deposited with Entomology Department, Annamalai University (EDAU), Chidambaram, Tamil Nadu, India and National Bureau of Agricultural Insect Resources (NBAIR) (formerly NBAII), Bengaluru, Karnataka, India. All measurements (except habitus images) are actual divisions under 40x (One division = 0.0025mm). Montage images were captured using Leica DM 750 phase contrast microscope for slide mounted parts and the habitus images using Leica M205C stereo zoom microscope.

Materials examined
Holotype Mesosoma (Image 9) 1.9x as long as wide. Pronotum 0.59x as long as wide, with a faint longitudinal carina medially, each lobe with about 25 setae dorsally, with reticulate sculpture ventrally. Mesoscutum 0.91x as long as pronotum, strongly reticulate (Image 10), with a pair of strong setae at posterolateral angle, lateral lobes also sculptured and again with a seta in each lobe posterolaterally. Axilla with longitudinal carinae laterally fading towards anterior scutellum, with one strong seta in each axilla, posterior end with reticulate sculpture. Scutellum 1.19x as long as mesoscutum, anterior scutellum with two placoid sensillae at middle, post scutellum with 2-3 longitudinal carinae on lateral sides and strongly foveate on the entire anterior margin; whole mesosoma ventrally reticulately sculptured. Metanotum band like medially and narrowing laterally and reticulately sculptured anterodorsally. Propodeum 0.82x as long as mesoscutum, and 0.67x as long as scutellum, with strong reticulate sculpture medially and laterally and with a pair of setae. Mesophragma broadly 'v' shaped almost reaching posterior margin of propodeum.
Fore wing (Image 7) 4.0x as long as wide, longest marginal cilia about 0.33x as long as maximum wing width; submarginal vein with eight, marginal vein with six setae along anterior margin. Hind wing (Image 8) 9.0x as long as wide, longest marginal cilia about 0.77x as long as maximum wing width. Legs: fore coxae 2.8x as long as wide; fore, mid and hind coxae respectively very faintly, faintly and strongly reticulately sculptured.
Metasoma (Image 11) petiole as long as wide with short spine like projections anterolaterally, and with reticulate sculpture dorsally. Gt1 and Gs1 smooth; ovipositor slightly exerted, as long as mesotibia.

Male (Image 2)
Body length 0.78mm. Simlar to female except for normal sexually dimorphic characters and following: Antenna with all flagellar segments longer than wide, each with two sensillae.

Host
Unknown.

Distribution
India: Karnataka and Tamil Nadu.

Etymology
This species is named after the species specific character of mesoscutum with reticulate sculpture.

Comments
Eubroncus scutatus can be separated from the closest species E. vertexus by its smooth vertex and sculptured mesoscutum (in vertexus vertex covered with scale-like sculpture and mesoscutum smooth), postscutellum with strong fovea along entire anterior margin (in vertexus fovea present only medially). Among other known species of Eubroncus, E. prodigiosus has scutum with faintly reticulate sculpture, but antennal measurements and wings are different [(in scutatus, scape is 4.3x as long as wide, in prodigiosus it is only 3x); fore wings 4x as long as wide in scutatus, 3.7x in prodigiosus; hind wings 9x long as wide in scutatus where as it is 7.8 to 8.2x in prodigiosus)].