Isotomurus Börner, 1903

Genus Isotomurus Börner, 1903 View in CoL

Isotomurus punctiferus Yosii, 1963 View in CoL ( Fig. 2)

Material examined: 4 specimens on slides, 165 specimens in alcohol; India, Assam, Panbari Range, Kheerani Beat , collected from leaf litter, 26°37’22.8’’N, 90°46’48’’E, 89.91 m a.s.l., (coll. Dilip Mondal) Reg. no- 3721/H14 GoogleMaps .

Diagnosis: Body length averages 1.87 mm. Ground colour pale yellow with pigment in body. Segments of antennae gradually darken with bluish tones ( Fig. 2A). Postero-dorsal region of the head with semi-lonershaped pigment patch. Anterior side of Th. II - Abd. V with pigmentation. Pre coxa, coxa and tita of each leg with comparatively dark in colour and faint blue/violet coloration respectively. Body with median longitudinal pigmentation from Th. II - Abd. II. The lateral part of each segment with blue/ violet pigmentation. From Abd. II - IV with small black spots in 3,3,1 pairs each spot represents bothriotricha ( Fig. 2B), ( Fig. 3A). Ventral tube with no such pigmentation. Antenna to head ratio as Ant .: Head -

5.8: 1. Antennal segment ratio as Ant . I: Ant . II: Ant . III: Ant . IV- 1: 1.4: 1.7: 1.8. Ant . III organs ( Fig. 3B) consist of 1-2 sensory setae that emerge from shallow grooves. 8+8 ommatidia. Labral setae 5,5,4. PAO elliptical with a slight notch. Unguis with a pair of dorsal lateral teeth. No inner tooth is present. Tenaculum quadridentate, corpus having 6 setae. VT posteriorly 20-30 setae. Mucro quadridentate, third tooth with proximal lamella ( Fig. 3C). Unguiculus outer lamella basally rounded ( Fig. 3D). Abdominal segment ratio as Abd. I: Abd. II: Abd. III: Abd. IV: Abd. V: Abd. VI- 1: 1.6: 2.4: 2.3: 1.2: 1. Furcula approximately 3 mm in length.

Chaetotaxy: Mac and Mes smooth. S-formula as 5,5/5,5,6,8,6 (s). ms-formula as 1,1/1,1,0,0,0 (ms) ( Fig. 4). Sensillum almost equal in size. All sensilla on Th. I

Isotomurus punctiferus Yosii, 1963 View in CoL ( Collembola View in CoL : Isotomidae View in CoL ), a new record to India with its taxonomic account and Th. II situated in p-row except ventrolateral sensilla comparatively anterior from posterior transverse row. Lateral sensilla on Abd. I in more anterior position. All sensilla on Abd. II and Abd. III on p-row. Two sensilla on Abd. IV in median transverse row and one sensilla in anterior transverse row, four sensilla in p-row. One sensilla on Abd. V in median transverse row and two sensilla in anterior transverse row, four sensilla on p-row.

Distribution in India: Assam (Manas National Park).

General distribution: Europe, South East Asia ( Bellinger et al., 1996 -2024).

Remarks: The examined species has quadridentate mucro. Unguis without an inner tooth. Body median longitudinal pigmentation is not continuous, however, Yosii (1963) mentioned that the pigmentation is continuous.