Proisotoma pakurensis, Mandal & Suman & Bhattacharya, 2017

Mandal, G. P., Suman, K. K. & Bhattacharya, K. K., 2017, Five new species of Collembola (Isotomidae) from Jharkhand, India, Records of the Zoological Survey of India 117 (2), pp. 97-112 : 98-100

1. Proisotoma pakurensis n. sp.

(Plate 1, Figures 1-21, Table 1)

Material examined: HOLOTYPE: female on slide, India: Jharkhand: Littipara, Tussar plantation garden, Pakur district , 27. viii. 2013, Lat & Long, N 24° 42’ 35.3” E 87° 36’ 51.8”, collected by G. P. Mandal, Registration No. 1980

/ H14/ZSI. PARATYPE: 01 ex on slide, India: Jharkhand: Littipara, Tussar plantation site, Pakur district , 27. viii. 2013, Lat and Long , N 24° 42’ 35.3” E 87° 36’ 51.8”, collected by G. P. Mandal, Registration No. 1981/H14/ ZSI; 01 ex on slide, India: Jharkhand: Littipara, Tussar plantation site, Pakur district , 27. viii. 2013, Lat & Long, N 24° 42’ 35.3” E 87° 36’ 51.8”, collected by G. P. Mandal, Registration No. 1982/H14/ZSI; 03 exs in ethyl alcohol, India: Jharkhand: Littipara, Tussar plantation site, Pakur district , 27. viii. 2013, Lat & Long, N 24° 42’ 35.3” E 87° 36’ 51.8”, collected by G. P. Mandal, Registration No. 1983/H14/ZSI .

Description: Body length up to 0.98 mm (excluding appendages).

Colour Pattern: Back ground colour yellow to grey, violet pigment present from head to Abd. VI on anterior side, the violet pigment form light transverse band through thorax to abdomen. Head slightly deep pigmented, eye patch deep blue-black, one light bluish dot like structure present in between two eyes. Posterior margin of the body grey in colour. Ant. I and II greyish but Ant.III and Ant. IV with light violet pigment anteriorly. Legs are yellowish in colour. Furcula white to grey in colour (Figure 1).

Head: Eyes 8+8, more or less equal (Figure 2). P.A.O present, kidney shaped, elongate, unconstricted, 2 smooth setae present near the base (Figure 3). P.A.O is

1.3 times as long as the diameter of largest eye. Antennal segment ratio in length as I: II: III: IV= 1: 1.7:1.5:2.7. Fourth antennal segment without apical bulb and distinct blunt setae (Figure 4). Third antennal segment with two small pegs like structure present (Figure 5). Maxillary outer lobe with 4 sublobal hairs. Labrum without papillae (Figure 6).

Thorax and Legs: Ratio of segments of Thorax II: III= 1:0.8. Unguis stout, with one inner tooth at basal half, no outer teeth and lateral tooth. Unguiculus short, broad, without teeth (Figure 7). Tenent hair long, thin and acuminate (Figure 8). Ventral tube with 6+6 distal lateral smooth setae (Figure 9). Trochanteral organ with 3+1+3 setae (Figure 10).

Abdomen: Ratio of segments of Abdomen I: II: III: IV: V: VI= 1: 1.04: 1.18: 1.53: 0.8: 0.3. Retinaculum with 4+4 teeth and 3 setae (Figure 11). Manubrium: dens: mucro = 4.48:5.08:1. Manubrium with six anterior setae and posterior side without setae but laterally with 28-30 small, smooth setae (Figures 12 and 13). Dens stout, broad and without distinct crenulations, anterior side with 14 short, smooth setae, posterior side 12 setae, laterally with 48 setae in 16 rows, each row having 3 setae (Figures 14 and 15). Mucro short, stout with 2 teeth and without lamellae (Figure 16). Fourth abdominal segment 1.29 times as long as third. Fifth and sixth abdominal segments separated by a non-setaceous band.

Body Chaetotaxy: Body clothed with normal smooth setae throughout head, thorax and abdomen. Cephalic portion clothed with normal setae without macro chaetae (Figure 17). Th. II – Abd. V also clothed with normal setae (Figures 18 & 19). Only 1+1 macrochaetae present on sixth abdominal segment (Figure 20). Ant. I with 3 and Ant.II with 2 basal microsensilla present (Figure 21). Ant.III with two peg like structures and Ant.IV with acuminate setae present.

Ecology: Found under leaf-litter of moist deciduous forest, particularly Tussar plantation garden of Littipara of Pakur district of Jharkhand.

Etymology: The new species is named after the type locality, Pakur district, Jharkhand, India.

Discussion: The new species from, Littipara Tussar plantation garden of Pakur district of Jharkhand, India can easily distinguished from other known species of Proisotoma by manubrial and dental chaetotaxy, number of setae on retinaculum and claw structure. It is close to

Characters Proisotoma nigromaculosa Folsom, 1932 Proisotoma pakurensis n. sp.

Colouration White to grey; darker specimens with interseg- Yellow to grey; violet pigment ranging from head to mental membranes, venter and appendages pale. Abd.VI anteriorly, form light transverse band.

Post Antennal Organ PAO broadly oval and weakly constricted medi- PAO kidney shaped, elongate, and without constric-

(P.A.O) ally, 2.5–3.7 times as long as diameter of largest tion, 1.3 times as long as diameter of largest eyes.

eyes.

Unguis and Unguic- Unguis with clear inner tooth but no outer teeth Unguis stout, with one inner tooth at basal half, no ulus and lateral tooth. Unguiculus simple. outer teeth and lateral tooth. Unguiculus short, broad, without teeth.

Tenent hair Tenent hair varying from acuminate to clearly Tenent hair long, thin and acuminate.

clavate.

Ventral tube Ventral tube with 4+4 distal lateral setae. Ventral tube with 6+6 distal lateral setae.

Trochanteral organ Trochanteral organ unknown. Trochanteral organ with 3+1+3 setae.

Retinaculum with setae Retinaculum with 4+4 teeth and 1 seta. Retinaculum with 4+4 teeth and 3 setae.

Manubrial setae Manubrium with 3+3 distal ventral setae. Manubrium with six anterior setae and without posterior setae but laterally with 28-30 small, smooth setae.

Proisotoma nigromaculosa Folsom, 1932 in having similar type of claw structures, mouth parts and bidentate mucro but strongly differs from Proisotoma nigromaculosa in the characteristics given in Table 1.

Subfamily Isotominae Schaffer, 1896

Genus Isotomurus Borner, 1903

1903. Isotomurus Borner, Ges. Naturwiss Freunde Berlin 1903:129-182 .

Type species: Podura palustris Muller, 1776

The genus Isotomurus erected by Börner (1903) includes characters: Furcula present. Post antennal organ present.

Mucro with 2 or more teeth. Fourth and fifth abdominal segments at least separated by nonsetaceous band.

Ventral manubrial setae 14 or more. Some abdominal setae multilaterally ciliate.

So far, about 70 species of the genus Isotomurus known from the world (Bellinger et al, 2016).

A checklist of Indian species, of Isotomurus as reference to their distribution in India and the World is provided.

1. Isotomurus balteatus ( Reuter,1876) .It was recorded from Maharashtra, Kerala,WestBengal,SikkimandArunachal Pradesh of India.Elsewhere: COSMOPOLITAN

2. Isotomurus ciliatus Stach, 1947 . It was recorded from West Bengal, Odisha, Uttar Pradesh of India; Elsewhere: POLAND.

3. Isotomurus palustris ( Muller, 1776) . It was recorded from West Bengal, Uttar Pradesh of India; Elsewhere: NORTH AMERICA .

4. Isotomurus jharkhandensis n. sp. This new species is described here from Ramgarh, Ranchi, East Singbhum and Dhanbad districts of Jharkhand of India.

5. Isotomurus dhanbadensis n. sp. This new species is described here from Dhanbad district of Jharkhand of India.

6. Isotomurus indicus n. sp. This new species is described here from Ramgarh and Jamtara districts of Jharkhand of India.

7. Isotomurus sahebganjensis n. sp. This new species is described here from Sahebganj district of Jharkhand of India.