﻿Two new species of Platensina Enderlein (Diptera, Tephritidae, Tephritinae, Dithrycini) from India

﻿Abstract Two new species of Platensina Enderlein, P.rabbanii David & Hancock, sp. nov., and P.flavistigma David & Hancock, sp. nov., are described from Meghalaya and southern India, respectively. Platensinarabbanii can be differentiated from P.alboapicalis Hering by the presence of a single hyaline indentation in cell r1 and the apical hyaline band in cell r2+3 restricted to the apex; P.flavistigma differs from P.quadrula Hardy by the presence of a yellow/fulvous pterostigma and shape of the epandrium. DNA barcode sequences of P.acrostacta (Wiedemann), P.flavistigma and P.platyptera Hendel were obtained and reported. Postabdominal descriptions and illustrations of P.acrostacta, P.platyptera and P.zodiacalis (Bezzi) are also provided along with keys to all 23 species and the 7 known from India.


Introduction
Platensina Enderlein is predominantly an Oriental and Australasian genus with 24 species recognized by Norrbom et al. (1999) [some generically misplaced] and 21 by Hancock (2012). They are medium-sized flies with broad, dark brown wings with hyaline indentations and spots. Host plants are not recorded except for Platensina acrostacta (Wiedemann), reared from stem galls of an undetermined Ludwigia species in southern India (Hardy 1973;Hancock 2012). Agarwal and Sueyoshi (2005) listed five species from India, while David and Ramani (2011) provided keys to four species from peninsular India and the Andaman and Nicobar Islands. Hancock (2012) recorded P. platyptera Hendel and P. quadrula Hardy from India, regarded records of P. amplipennis (Walker) from India as misidentifications of P. platyptera and provided a key to species of Platensina. In this paper two new species, one collected from Meghalaya and one from southern India, are described, along with descriptions of postabdominal structures of other species recorded from India except P. tetrica Hering and P. fulvifacies Hering, as specimens of these two taxa were not available for study.
A key to species of Platensina recorded from India is provided, together with a revised key to all known species.

Material and methods
Specimens studied are deposited in the National Insect Museum, ICAR -National Bureau of Agricultural Insect Resources, Bengaluru, India (NIM).
Collections were done by sweep netting. Images of specimens were taken using a Leica DFC 420 camera mounted on a Leica M205A stereo zoom microscope; images of genitalia were taken using an 8 MP camera temporarily attached to a Leica DM 1000 compound research microscope; the images were stacked and combined to a single image using Combine ZP (Hadley 2011). Measurements of male and female genitalia were taken using Leica Automontage Software, LAS 3.4. Terminology adopted here follows White et al. (1999) and wing terminology by Cumming and Wood (2017).
One hind leg was removed from one specimen of each of three species and used for DNA extraction. The DNA extraction was performed using a DNeasy Blood and Tissue Kit (Qiagen India Pvt. Ltd.) following the manufacturers' instruction. For the molecular study, the standard DNA barcoding region of the mitochondrial COI gene was sequenced and the PCR was performed using the Universal COI primers (LCO1490/HCO2198) (David et al. 2020). The sequences were annotated using NCBI Blast tools and submitted to the NCBI GenBank Database where accession numbers were obtained (Platensina flavistigma -MT019893; Platensina acrostacta -MT019891; Platensina platyptera -MW448367).
The pairwise genetic distance between three species of Platensina viz., P. acrostacta, P. platyptera and P. flavistigma has been calculated using mitochondrial COI gene sequences. Analyses were conducted using the Maximum Composite Likelihood model (Tamura et al. 2004). This analysis involved 4 nucleotide sequences. Codon positions included were 1 st +2 nd +3 rd . All positions with less than 95% site coverage were eliminated, i.e., fewer than 5% alignment gaps, missing data, and ambiguous bases were allowed at any position (partial deletion option). There were a total of 557 positions in the final dataset. Evolutionary analyses were conducted in MEGA11 (Tamura et al. 2021).
Diagnosis. Medium-sized flies (4-5 mm long), with frons as wide as long, three frontal setae, two orbital setae, well developed ocellar setae. First flagellomere shorter than face, with short-pilose arista, face usually fulvous, black in males of a few species. Scutum grey pubescent with yellow-white reclinate setulae; scutellum flat with one or two pairs of setae, apical pair less than half length of basal setae or absent. Wing broad, often distinctly angled along posterior margin, dark brown with hyaline indentations and subhyaline spots. Abdomen predominantly black with fulvous lateral regions. Epandrium broad, without demarcation between epandrium and lateral surstylus, lateral surstylus broad, epandrium elongate-oval in posterior view; medial surstylus with well sclerotised prensisetae (lateral one broader than medial one), proctiger not higher than epandrium, glans of phallus stout, with single sclerotised acrophallus. Taeniae short (0.25 of eversible membrane); spicules on eversible membrane conical; aculeus dorsoventrally flattened, tip conical, with reduced preapical setae; spermathecae clubshaped, with numerous papillae.
Key to species of Platensina from India Wing with discal spots small and often indistinct or subhyaline; cell r 1 with 0-2 small hyaline indentations from costa in basal portion beyond stigma, often not crossing cell; cell cua with 3 small, isolated hyaline marginal spots and with or without additional small, isolated discal spots; holotype illustrated by Hering 1939a, fig. 14 Male wing without hyaline spots or indentations apart from small marginal indentation in cell r 1 at apex of vein R 1 and crescentic hyaline apex; female wing with crescentic hyaline apex plus hyaline marginal spots and indentations and subbasal hyaline spot in cell dm but no spot near base of cell r 4+5 ; illustrated by Wang 1998, fig One pair of scutellar setae, apicals absent; illustrated by Bezzi 1913, fig. 65, Hardy 1973, pl. v, fig. 45, Hardy 1974, fig. 130, Wang 1998 Wing cell r 1 with 2 large and quadrate hyaline indentations, distal one broader than wide, plus subapical posterior spot not reaching costa; cell m with 2 elongate hyaline indentations, the anterior one much smaller and narrower than the posterior one; cell cua with 3 broad hyaline indentations, the basal pair crossing or almost crossing cell, plus basally with extension of large hyaline mark in anal lobe; male with distinct white or silvery parafacial stripes (females unknown  Wing cell r 1 with basal hyaline indentations often reduced to 0-2 small hyaline spots (especially in males, better developed in females); cell cua with 3 small and isolated hyaline marginal spots and with or without additional small and isolated discal spots; anal lobe with 2 distinct hyaline marginal spots; illustrated by Hardy 1973, pl. v, fig. 44  Wing cell m with a small anterobasal hyaline spot and no marginal spots; cell cua with 2 undivided indentations almost crossing cell; cell r 4+5 with basal spot large and ovate, much larger than the 2 distinct spots in cell dm; illustrated by Hardy 1973, pl. v, fig. 43  Diagnosis. This species is similar to P. alboapicalis Hering from Burma in the presence of an apical hyaline band extending from cell r 2+3 to cell m 1 but can be differentiated by the presence of a single hyaline indentation in cell r 2+3 , versus two hyaline indentations and spot in P. alboapicalis; the apical hyaline band restricted to the apical one-third of cell r 2+3 , versus the whole of apex of cell r 2+3 in P. alboapicalis; and the hyaline indentations in cell cua ending well before vein CuA, unlike in P. alboapicalis where they almost reach vein CuA.
Description. Male. Medium-sized fly (4.03 mm long) with broad, dark brown wing with hyaline apex.  Head (Fig. 2): nearly as high as long; frons fulvous with three pairs of frontal setae and two pairs of orbital setae (posterior one white); ocellar triangle fuscous, with well developed ocellar setae; medial vertical seta black; lateral vertical seta, paravertical seta and postocellar seta lanceolate and white; postocular setae black interspersed with prominent, white lanceolate setae. Face fulvous without any markings. Scape and pedicel fulvous, first flagellomere less than half length of face, concolorous with frons, arista short pilose. Gena narrow, with prominent genal seta, subvibrissal setae present.
Wing (Fig. 6) broad, with posterior margin evenly rounded, length 4.47 mm; length/ width ratio-2.10, predominantly dark brown, with hyaline indentations and spots; cell bc hyaline, cell c predominantly moderate brown, with narrow basal and broader medial hyaline areas, pterostigma entirely moderate brown without any hyaline markings, cell r 1 with one trapezoidal basal hyaline indentation not extending beyond vein R 2+3 , cell r 4+5 with elongate subbasal hyaline spot, cell dm with large hyaline spot at basal third, cell cua with two short hyaline indentations not reaching vein CuA, and apical hyaline band extending from apex of cell r 2+3 to cell m; anal lobe and alula dark brown.
Habitat. Marshy grasslands. Etymology. The species is named after the collector, Rabbani Mehaboob K. It is a noun in apposition. Diagnosis. This species is similar to P. quadrula Hardy from Thailand, Cambodia and Vietnam in the presence of two broad quadrate areas in wing cell r 1 , an enlarged basal discal spot in cell r 4+5 and large, broad hyaline indentations in cell cua. It can be differentiated by the lack of silvery facial spots and white rather than silvery parafacial stripes in males, as well as the angulate posterior wing margin, pterostigma predominantly fulvous/yellow and pale brown, and epandrium of uniform width throughout its length, whereas in P. quadrula the parafacial is silvery rather than white and facial silvery spots are present lateroventrally in males, the wing is evenly rounded posteriorly, the pterostigma is hyaline basally and dark brown apically, and the epandrium tapers apically. This species was mistakenly listed as P. quadrula from India by Hancock (2012).
Wing (Fig. 16) broad, angulate, length 4.44-4.99 mm, length/width ratio, 1.92-2.05; predominantly dark brown with hyaline indentations and spots; cell bc hyaline, cell c predominantly hyaline with pale basal and medial infuscations, pterostigma fulvous basally, dark brown apically, cell r 1 with two broad quadrate indentations and small posterior subapical hyaline spot, the proximal quadrate indentation extended to vein R 4+5 , cell r 4+5 with large circular hyaline spot near base and large, semicircular hyaline apical spot, cell dm with two large hyaline spots, cell m with two marginal hyaline marks, subbasal one much larger than subapical one, cells r 2+3 and r 4+5 with indistinct and isolated pale brown subapical spots, cell cua with three large marginal hyaline indentations, basal two almost reaching vein CuA, and anal lobe with two broad subhyaline markings, proximal one crossing into cell cua.
Female. Unknown Etymology. The specific name is derived from two Latin words flavus (=yellow) and stigma (=ptersotigma).
Distribution. This species is widespread from India (Kerala, Karnataka, Meghalaya, Andaman and Nicobar Islands) to Japan and Australasia (Hancock 2012
Distribution. This species is known in India only from the type locality in Tamil Nadu. Elsewhere, it is known from China, Taiwan, Vietnam and West Malaysia (Hancock 2012).
Distribution. This species is widespread from India (Karnataka, Assam) and Sri Lanka to southern China and Australia (Hancock 2012).
Evolutionary divergence among the Indian species of Platensina Table 1 shows the pair-wise evolutionary divergence/distance between four sequences available in NCBI database for three species namely P. acrostacta, P. platyptera and P. flavistigma. Evolutionary distance between P. flavistigma David & Hancock, sp. nov. and P. acrostacta is 0.0429 and between P. flavistigma and P. platyptera is 0.0759 which reveals that P. flavistigma is a distinct species in Platensina based on the available sequences. Among the species included in the analysis, evolutionary distance between P. platyptera and P. acrostacta was the highest (0.0837), which is evident in the morphological differences between these two species with respect to facial markings and wing pattern.