Thalerosphyrus sartorii Vasanth, Kubendran & Subramanian, 2025

Thalerosphyrus sartorii Vasanth, Kubendran & Subramanian sp. nov.

( Figs 51–95 View FIGURES 51–52 View FIGURES 53–54 View FIGURES 55–62 View FIGURES 63–67 View FIGURES 68–77 View FIGURES 78–87 View FIGURES 88–95 )

Material examined. Holotype. Mature larva, INDIA, Tamil Nadu, Erode district, Gunderipallam , Vanchimedu river , 11.57280°N, 77.37006°E, 314 m. 02.II.2023, coll. R. Babu & Party (Reg. No. I /E/866) GoogleMaps . Paratypes: 4 larvae, same place and data as holotype (Reg. No. I /E/867) GoogleMaps ; 3 larvae, Erode district , Matheshwaram kuttai, Kottadai, 11.65037°N, 77.13364°E, 948 m GoogleMaps . 04.II.2023, coll. R. Babu & Party (Reg. No. I /E/868) .

Description. Mature larva ( Fig. 51 View FIGURES 51–52 ). Length (mm): body 11–11.5; cerci 13–13.5. ♀ body 12.5–13.5; cerci 14.5–15.5; prothorax width 4.2–4.5 ( Fig. 78 View FIGURES 78–87 ).

Colour. Generally pale brownish. Antennae brown and much shorter than the width of head ( Fig. 95 View FIGURES 88–95 ). Head circular, brown, and flattened; anterior margin of the head with numerous small setae; a pair of pale maculae on the front of head, and dorsal surface has four pale dots; ocelli with three black dots mixed with pale color in the middle.

Head. Mouthparts: Labrum moderately broad, 3.5× wider than long, anterior margin straight, medio-ventrally with a curved row composed of 7–8 long stout setae ( Figs 57–58 View FIGURES 55–62 ); dorsal surface and anterior margin covered with long, hair-like and stout setae; ventral surface of anterior margin with numerous long hair-like setae lateral margin slightly concave. Mandibles strongly bent in distal part; anterolateral margins with several rows of dense long hair-like setae; anterolateral margins medially bulged ( Figs 60–63 View FIGURES 55–62 View FIGURES 63–67 ). Right mandible with outer incisor serrated on inner margin, composed of 8 blunt teeth; inner incisor with two teeth, apically sharp; prostheca with 10–11 thick fimbriate submarginal setae; mola joined, posterior margin with 5–6 hair-like setae ( Figs 60–61 View FIGURES 55–62 ). Left mandible with outer incisor serrated with 13 blunt teeth; inner incisor apically bulged with trifid teeth, anterior tooth with small stout setae at the tip; prostheca with 11 thick fimbriate setae; mola with 6–7 setae and posterior median margin with 5 hair-like setae ( Figs 62–63 View FIGURES 55–62 View FIGURES 63–67 ). Maxilla with long, simple setae on inner margin of galea-lacinia and with fimbriate setae scattered on ventral surface. Segment I of maxillary palp with rows of thin and simple setae on outer margins, dorsal surface with 4 small simple setae; segment II large with rows of numerous hair-like setae on outer margin; apical segment small, pointed, with rows of simple setae on outer margin. Crown of the galea-lacinia of maxillae with 14–15 comb-shaped setae ( Fig. 64 View FIGURES 63–67 ). Hypopharynx narrow, lingua with tuft of small robust setae (lingua slightly damaged), superlinguae slightly expanded laterally, densely covered with long and thin setae replaced apex with small setae up to lower part of the superlinguae ( Fig. 59 View FIGURES 55–62 ). Labium well developed, glossae dorsally with two distinct long setae and median patch of feathered setae; inner margin slightly concave, outer margin straight or serrated ( Figs 65–67 View FIGURES 63–67 ).

Thorax. Pronotum moderately enlarged laterally, medially concave, wider than the head, and basally not fused to the mesonotum ( Figs 51–52 View FIGURES 51–52 , 78 View FIGURES 78–87 ), anterior margin of pronotum with a small projection at apex, anteromedially dark black indentation marking, and posterior part of medially with a pair of black spots ( Fig. 78 View FIGURES 78–87 ). Mesonotum pale and brown color mixed, anterolaterally with deep concavity ( Fig. 78 View FIGURES 78–87 ). Legs brown with pale markings ( Figs 68, 71, 75 View FIGURES 68–77 ). Foreleg: femur with a row of long strong setae on dorsal margin, anterior surface with numerous blunt stout setae, medially with small indentation of middle, and distally with a black spot ( Figs 68–70 View FIGURES 68–77 ). Midleg: femur anterior surface with numerous stout setae, median and distally with black spot; tibia dorsal surface with small stout feathered setae, inner side with small thick setae, and outer margin with a row of hair-like setae ( Figs 71–74 View FIGURES 68–77 ). Hindleg: femur with dorsal surface triangle-shaped setae, clearly pointed median, and distally with black spot; tibia with dorsally two rows of stout setae, inner side without setae and marginal and submarginal 17–18 pointed setae ( Figs 75–77 View FIGURES 68–77 ). Claw with 3–4 blunt denticles ( Fig. 77 View FIGURES 68–77 ).

Abdomen. Posterolateral expansions on terga III–VIII parallel to abdomen, poorly developed on tergum III, weakly developed on terga IV–V, moderately developed on terga VI–VIII ( Figs 53–54 View FIGURES 53–54 ). Dorsal surface of terga I–III pale brown, medially a brown spot; tergum III with laterally black spot; terga IV–V medially with a distinct pale-yellow spot ( Fig. 51 View FIGURES 51–52 ); terga IV–X brown mixed with pale yellow ( Fig. 53 View FIGURES 53–54 ); sternum pale yellowish or pale brownish (mature larva), sterna III–VII laterally with brown spot ( Fig 53–54 View FIGURES 53–54 ). Posterior margins of terga with irregular pointed teeth and a row of 2–3 microdenticles ( Figs 84–86 View FIGURES 78–87 ) and each tergite laterally with small simple setae ( Fig. 85 View FIGURES 78–87 ). Gill I convex, asymmetrical, elongated, apically moderately sharp, 2.5× longer than wide and ventral lamella long, fimbriate ( Figs 88 View FIGURES 88–95 , 114 View FIGURES 111–114 ); Gill II–VI strongly asymmetrical, length and width subequal ( Figs 89–93 View FIGURES 88–95 ). Gill VII long, 2.5× longer than wide ( Fig. 94 View FIGURES 88–95 ). Cerci pale brownish with medium brown bands increasing in size towards apex. Paracercus pale whitish with yellow, with a dark brown band on 3–4 segments and each segment surrounded with pointed small yellowish spine-like setae ( Fig. 55 View FIGURES 55–62 ).

Genitals. Protopenis ( Figs 80–82 View FIGURES 78–87 ): male genitalia yellowish, penis fused, V-shaped medially, apically blunt, and laterally with tapered square, tergum X triangular and apically with numerous stout setae ( Fig. 81 View FIGURES 78–87 ). Forceps proximally broad and towards narrow apically.

Adult. Unknown.

Etymology. This species is named in honour of Dr. Michel Sartori in recognition of his significant contributions to the genus Thalerosphyrus .

Distribution. Erode district, Tamil Nadu ( India) ( Fig. 112 View FIGURES 111–114 ).

Diagnosis. Thalerosphyrus sartorii Vasanth, Kubendran & Subramanian sp. nov. is similar to T. flowersi and T. meghalayensis , but it can be distinguished from all known species of Thalerosphyrus by the following combination of characters: (i) posterolateral expansions on terga III–VIII, terga VI–VIII moderately developed, tergum III poorly developed, weakly developed on terga IV–V ( Figs 51–54 View FIGURES 51–52 View FIGURES 53–54 ); (ii) gill I convex, asymmetrical, elongate, 2.5× longer than wide ( Fig. 88 View FIGURES 88–95 ); (iii) abdominal tergum III dorsolaterally with black markings ( Fig. 53 View FIGURES 53–54 ); (iv) abdominal sterna III–VII with laterally black streaks ( Fig 54 View FIGURES 53–54 ); (v) posterior margins of terga with irregular pointed teeth and a row of 2–3 micro denticles ( Figs 84–86 View FIGURES 78–87 ); (vi) pronotum moderately enlarged laterally, with anteromedian black marking and submedian pair of black spots ( Figs 51 View FIGURES 51–52 , 78 View FIGURES 78–87 ); (vii) all femora medially with black maculae and blunt stout setae ( Figs 68, 71, 75 View FIGURES 68–77 ); (viii) hind femur triangular-shaped setae, clearly pointed ( Fig. 75 View FIGURES 68–77 ); (xi) claw with 3–4 blunt denticles ( Fig. 77 View FIGURES 68–77 ); (x) labrum moderately expanded laterally, anterior margin straight, medio-ventrally with a curved row composed of 7–8 long stout setae each; lateral margin slightly concave ( Figs 57–58 View FIGURES 55–62 ); (xi) hypopharynx narrow and superlinguae slightly expanded laterally with apically with small setae ( Fig. 59 View FIGURES 55–62 ); (xii) mandibles with lateral margin medially bulged, of mandibles and left mandible inner incisor with three teeth with small stout setae joined with first teeth ( Figs 60–63 View FIGURES 55–62 View FIGURES 63–67 ); (xiii) maxillae broad, galea-lacinia with 14–15 comb-shaped setae ( Fig. 64 View FIGURES 63–67 ); (xiv) glossae with slightly concave ( Fig. 66 View FIGURES 63–67 ).