Megalabops dharaensis, Feijen & Feijen & O., 2019

Megalabops dharaensis n. sp.

( Figs 11–25, 27)

Diopsis quadriguttata View in CoL auct.: Brunetti 1907: 165 (in part, specimens from Kurseong are most likely to be conspecific with M. dharaensis n. sp., the distance from the type locality is about 25 km).

Megalabops spec. “A”: Kotrba et al. 2013: 190.

LSID: urn:lsid:zoobank.org:act:714C07DD-2F71-4EB1-905D-636E51088F5F .

Etymology: The species originates from the tea estate Gopaldhara near Darjeeling. Gopal was the name of a person, while dhara in Hindi means “stream of clear water”. Given the link of Diopsidae to the presence of water, it is considered appropriate to name this species Megalabops dharaensis .

Diagnosis: Megalabops dharaensis n. sp. can be recognised by its wing pattern (3 complete crossbands, straight distal edge of preapical crossband, 4 hyaline spots), distribution of microtrichia on the wing (glabrous base and glabrous areas in proximal anterior spot), very long IVS, long OVS, small base of IVS, absence of facial teeth, incrassate front femora with ratio length/width ~3.5, undivided, rectangular female sternum 6, somewhat curved female sternum 7, spiracle 7 in membrane in both sexes, rectangular to pentagonal subanal plate, rather elongate female cerci, convoluted sections of spermathecal ducts near spermathecae, elongate spermathecae with 20–24 protuberances, articulated, apically bilobed, surstyli with large areas of microtrichia and apically some long setulae, convex male cerci, winged and dorsally strongly curved phallapodeme, broadly fan-shaped ejaculatory apodeme and sexual homomorphy with regards to the eye span.

Megalabops dharaensis n. sp. with its two anterior and two posterior hyaline wing spots belongs to the M. quadriguttata species-group, one of the two species-groups in Megalabops .

Description: Body length ♀ 6.3 mm, ♂ 4.9 mm ± SE 0.5 (range 4.4–5.3, n=2); eye span ♀ 3.9 mm, ♂ 3.3 mm ± 0.3 (3.0–3.5, n=2); wing length ♀ 4.6 mm, ♂ 3.8 mm ± 0.4 (3.4–4.2, n=2); length of scutellar spine ♀ 0.99 mm, ♂ 0.78 mm ± 0.05 (0.74–0.84, n=2).

Head. Central part brown, thinly pollinose, on frons and posteriorly more glossy; frons ( Figs 11, 15) with U-shaped depression in front of ocellar tubercle, lateral areas roughened, a ridge around frons; arcuate groove dark brown; upper half of face protruding, centrally two vague protuberances, a few pale setulae, facial corners rounded ( Figs 11–15); eye span very small in ♀ and ♂ (respectively 38 % and 33 % smaller than body length); stalks brown, broad apical parts blackish, pollinose; IVS very long, 6× diameter of eye stalk, base of IVS small, just more than half the stalk diameter; OVS long, 4× stalk diameter ( Figs 11, 15). [Given that only 1♀ and 2♂ were available for measurements, the rate of dimorphy D could not be calculated. Four Megalabops species for which large data sets were available were sexually homomorphic with regard to eye span with D varying from -0.01 to -0.05. Given that the three data points (span/body length) for M. dharaensis n. sp. are collinear and that Megalabops appears to be a uniformly homomorphic genus, it is safe to state that also M. dharaensis n. sp. is homomorphic with regard to the eye span.]

Thorax. Collar glossy brown, posterodorsally and laterally pollinose ( Figs 12, 14); scutum uniformly greyish brown pollinose, scutellum brown pollinose, scutellar spines glossy dark brown, but base of spines pollinose; upper half of pleura pollinose, lower half glossy brown except for pollinose posterior area; sterna glossy brown; supra-alar spines ( Figs 12–14) medium-sized, about twice as long as pleurotergal spines, laterally and upward directed; scutellar spines long, curved upward and outward, diverging under angle of 125°, ratio scutellar spine/scutellum length in ♀ 3.42 (n=1) and in ♂ 3.45 (range 3.41–3.49, n=2), ratio scutellar spine/body length in ♀ and ♂ 0.16; pleurotergal spines short, blunt, posterolaterally directed; apical seta long, 47 % of length of scutellar spine, posteriorly directed; some setulae on scutum, scutellar spines with setulae on small warts.

Wing. Three crossbands ( Fig. 13), preapical and central band equal in width and forming an H-configuration; wing apex (apical sixth) slightly infuscated ( Figs 12, 13), a bit paler near preapical crossband; preapical band with darker anterior half and straight apical edge; central band including crossveins r–m and dm–m; basal band narrow and irregular, broadening posteriorly; preapical band and central band linked around vein M 1, central band and basal band linked around vein M 4; between the three bands four almost hyaline spots (from which the name Diopsis quadriguttata originated, and thus characteristic for the whole M. quadriguttata species-group), one spot in cells r1 and r2+3 just extending in cell r4+5, one spot basally in cell m1, one spot in cells r1, br and bm+dm and one spot centrally in cell m4; slightly darker smudge from tip of cell cua; glabrous basal areas include cell c, basal quarter of cell r1, parts of the anterior, proximal hyaline spot, basal half of cell br, basal third of cell bm+dm and most of cell cua.

Legs. Front leg brown ( Fig. 12), tibia and metatarsus darker, pollinose anteriorly and basally on coxa and inner side of femur; mid and hind leg brown with darker apex of femora and slightly darker tibiae; femur 1 ( Figs 12, 16) incrassate in both sexes, ratio of length/width in ♀ 3.4 and in ♂ 3.5 (range 3.3–3.6, n=2), tubercles on distal five-sixth, inner row in ♀ with 26.5 tubercles ± SE 0.5 (range 26–27, n=2) and in ♂ with 23.7 tubercles ± 0.3 (range 23–24, n=3), outer row in ♀ with 23.5 tubercles ± 0.5 (range 23–24, n=2) and in ♂ with 20.0 tubercles ±1.0 (range 18–21, n=3), outer row with small gap.

Preabdomen. Dorsally dark brown, thinly pollinose, almost glossy, around border area of terga 1 and 2 denser pollinosity, tergum 3 anterolaterally with densely pollinose spots ( Fig. 14); seam between terga 2 and 3 visible; sternum 1 dark brown, glossy; other sterna brown pollinose; sternum 1 basally linked to syntergum ( Fig. 19); spiracle 1 in tergum; intersternite well defined ( Fig. 19), laterally vaguely connected to sternum 2.

Female postabdomen. Strongly deflexed, terga 6 and 7 single rectangular sclerites ( Figs 19, 24); tergum 8 represented by two sclerites ( Figs 17, 19), covered by microtrichia except for anterolateral corners; tergum 10 with one pair of strong setulae; cerci rather elongate, ratio of length/width 3.5, covered with microtrichia and a number of setulae; sterna 5 and 6 single rectangular sclerites, slightly constricted posteriorly on the meson ( Fig. 19); sternum 7 single curved sclerite, slightly broadening laterally; sternum 8 represented by two rounded sclerites; spiracle 7 in membrane; subanal plate ( Fig. 18) rectangular to pentagonal with somewhat pronounced medial apex, posteriorly two pairs of long setulae and two pairs of short setulae; spermathecae ( Figs 20, 24) rather elongate with a large number (24 on single theca, 20 and 22 on the pair) of evenly distributed protuberances, strongly sclerotised, spermathecal ducts with the typical Megalabops convolutions just before they enter the base of the spermathecal capsules; sclerotised ring of ventral vagina wall ( Figs 24, 25) long, anteriorly acute.

Male postabdomen. Sternum 5 a single plate, posteriorly with rounded gap on meson, sternum 6 lost in preparation; synsternum 7+8 without sclerotised connection to epandrial sclerites; left and right spiracles 7 well in membrane, right spiracle 7 at greater distance from synsternum 7+8; epandrium ( Fig. 21) rounded, with about 21 pairs of setulae, covered with microtrichia; surstyli articulated, somewhat constricted sub-basally ( Figs 21, 27), in lateral view ( Fig. 27) concave apically, in posterior view ( Fig. 21) with very typical, bilobed appearance apically, large sections of lateral, inner and posterior sides covered with microtrichia, on distal half a number of setulae and apically some rather long setulae ( Figs 21, 27); surstyli connected to lateral side of cerci, not interconnected via processus longi; cerci ( Fig. 21) rather small and strongly convex, ratio length/width (in posterior view, not flattened) 1.6, covered with microtrichia and setulae; phallapodeme ( Fig. 23) basically very typical for Megalabops , very solidly built, anterior arm with small ventral wings and strongly curved dorsal edge, apodeme centrally very “high”, posterior arm almost twice as long as anterior arm, vane basally constricted; aedeagus ( Fig. 23) shown in extended ‘in copula’ position, rather long genital process (for terminology see Kotrba et al. 2013) sticking out from apex; connections between phallapodeme, hypandrium and aedeagus as in Fig. 23; ejaculatory apodeme broadly fan-shaped ( Fig. 22).

Holotype: ♂ India: Gopaldhara , Darjeeling, 3440–4720 ft (1050–1450 m), 2.ix.1916, 26°55'41"N 88°09'43"E, H. Steevens ( RMNH). GoogleMaps

Paratypes: 1♀ 1♂ (in copula), same data as holotype, except for date: 15.viii.1916. Note: The pair of paratypes was pinned in ‘in copula’ position. It was possible to separate the pair, while the genitalia remained in extended position GoogleMaps .

Distribution: M. dharaensis n. sp. is only known from the Darjeeling district in West Bengal, India. Most Megalabops species have a relatively small distribution range. M. quadriguttata appears to form the exception with its distribution ranging from West Malaysia to Vietnam.

Remarks: Megalabops can be divided into two species-groups. The most common one is the M. quadriguttata group characterised by the two anterior and two posterior hyaline wing spots. The other species-group consists of yet to be described species characterised by absence of the H-configuration on the wing, an irregular central cross band and an incomplete basal band. For separating species, genitalia provide, by far, the most reliable characters, like, for example, the differences in surstyli between M. bigotii , M. dharaensis n. sp. and M. quadriguttata ( Figs 26–29).

More species will eventually have to be described from India. Except for paramount differences in genitalia, these species can be distinguished by small differences in wing pattern and pollinosity patterns on the scutum.