Sclerotia aquatilis (Thancharoen, 2007)

Ghosh, Srinjana, Sarkar, Subhankar Kumar & Chakraborty, Susanta, 2023, New distributional records of fireflies (Coleoptera, Lampyridae, Luciolinae) from two Eastern States of India with notes on their biology and an updated Indian checklist, Biodiversity Data Journal 11, pp. 98948-98948 : 98948

Sclerotia aquatilis (Thancharoen, 2007)

Materials

Type status: Other material. Occurrence : recordedBy: Srinjana Ghosh ; sex: 3 males; occurrenceID: E4AA985E-C1E3-5AA1-AE21-F90D309A65D0; Taxon : scientificName: Sclerotia aquatilis (Thancharoen, 2007); family: Lampyridae ; Location : country: India; countryCode: Ind ; stateProvince: West Benga ; locality: Kulpi , South 24 Parganas ; verbatimCoordinates: 22°4'48'' N, 88°17'60'' E; Event : samplingProtocol: Net sweeping; eventDate: 10-September-17; Record Level: collectionCode: VUEC-0025, VUEC-0026, VUEC-0027; basisOfRecord: Preserved Specimen Type status: Other material. Occurrence: recordedBy: Srinjana Ghosh; sex: 1 male; occurrenceID: CDFE2902-8558-5D26-82DF-A912DDAAB01A; Taxon : scientificName: Sclerotia aquatilis (Thancharoen, 2007); family: Lampyridae ; Location : country: India; countryCode: Ind ; stateProvince: Odisha; locality: near Chandipore coast, Balasore ; verbatimCoordinates: 21°29'36'' N, 86°55'19''E; Event : samplingProtocol: Net sweeping; eventDate: 8-May-18; Record Level : collectionCode: VUEC-0025, VUEC-0026, VUEC-0027; basisOfRecord: Preserved Specimen Type status: Other material. Occurrence: recordedBy: Srinjana Ghosh; sex: 2 males; occurrenceID: 2AD 51D56-287E-5592-B332-59E3E88F9371; Taxon : scientificName: Sclerotia aquatilis (Thancharoen, 2007); family: Lampyridae ; Location : country: India ; countryCode: Ind ; stateProvince: West Bengal; locality: Egra , East Midnapore ; verbatimCoordinates: 21°53' 56'' N, 87°31'48'' E; Event : samplingProtocol: Hand picking; eventDate: 11-August-18; Record Level : collectionCode: VUEC-0063, VUEC-0064; basisOfRecord: Preserved Specimen Type status: Other material. Occurrence: recordedBy: Srinjana Ghosh; sex: 4 males, 3 females; occurrenceID: 8563A1F5-DE6F-5516-8B68-467F2BE5DB2D; Taxon : scientificName: Sclerotia aquatilis (Thancharoen, 2007); family: Lampyridae ; Location : country: India ; countryCode: Ind ; stateProvince: West Bengal; locality: near Sajnekhali Bird Sanctuary , Sundarban Biosphere Reserve , South 24 Parganas ; verbatimCoordinates: 22°7'12''N, 88°46'49'' E; Event : samplingProtocol: Net sweeping; eventDate: 14-July-19; Record Level : collectionCode: VUEC-0096, VUEC-0097, VUEC-0098, VUEC-0099, VUEC-0100, VUEC-0101, VUEC-0102; basisOfRecord: Preserved Specimen

Diagnosis

Length 9-11 mm; Width 3.5-4 mm; PN, MN and MS pale brownish-yellow, elytra dark brown with the sutural and lateral margins bright yellow, ventrites pale brown, legs pale brown with the apical parts of tibae and entire tarsi dark brown (Fig. 10). Scl. aquatilis can be distinguished from Scl. substriata (the other known species of the genus from India) by the following set of male characters: V4 and V5 having dark brown patches along the posterior margin with the dark patch of V5 occupying approximately 2/3 of the part posteriorly (in case of Scl. substriata , whole part of V4 and V5 dark brown in colour); LO occupies the entire V6 and V7, except for a small median emargination at the anterior part of V7 (in case of Scl. substriata , the anterior median emargination of the LO in V7 is of comparatively greater depth). Male genitalia (Fig. 11): Aedeagus L/W 2.1, aedeagal sheath sternite having an oblique bar and a small median posterior emargination, anteromedian margin of sheath tergite emarginated (in case of Scl. substriata , the transverse oblique ridge in posterior half of sheath sternite is not present, elongate pointed projection of the right side of the posterior margin of the sheath sternite is not found and there is rounded prolongation of the median anterior margin of the aedeagal sheath tergite); Sclerites (Fig. 11 a, b) - distal end of triangular-shaped ventral sclerite is rounded in shape, its margin is not sclerotised, anterolateral corners acute; right sclerite possesses three projections to the right, of those, the posterior one apically acute, median one is dorsolaterally inclined with the apical end slender and rounded, the third one is the longest, arises in an emargination between the other two, ventrolaterally inclined with rounded hollow apex; left sclerite also possesses three arms, all of which are apically rounded with the anterior one expanded.

Biology

Males of Scl. aquatilis were found perching on macrophyte surfaces at the onset of darkness. Their average flight height ranged between 2 to 5 metres. Females are macropterous. Metapneustic larvae are exclusively aquatic in nature and the later instars lack gills, while in initial instars, lateral bristles function as gills ( Fu and Ballantyne 2009). The 1st - 2nd instar larvae obtain dissolved oxygen through tracheal gills, whereas the 3rd - 6th instar back-swimmer larvae, without tracheal gills, swim just below the water surface and expose their abdominal segments to air to breath by their terminal spiracles ( Fu et al. 2005, Zheng et al. 2008). Adult individuals were observed near aquatic sites.