Troglopedetes Joseph, 1872

Jantarit, Sopark, Surakhamhaeng, Katthaleeya & Deharveng, Louis, 2020, The multiformity of antennal chaetae in Troglopedetes Joseph, 1872 (Collembola, Paronellidae, Troglopedetinae), with descriptions of two new species from Thailand, ZooKeys 987, pp. 1-40 : 1

Genus Troglopedetes Joseph, 1872

Type species.

Troglopedetes albus Joseph, 1872

Medium sized Paronellidae . Body colour white, sometimes with light orange to red pigment dots. Eyes per side 0-3. Scales present on antenna, head, body and ventral side of furca, absent on ventral tube and legs. Pseudopores on tergites arranged as 1, 1/1, 1, 1, 1 by half tergite from Th. II to Abd. IV, with a row of 4+4 pseudopores behind the posterior row of chaetae of Abd. IV. Labial basis chaetotaxy as M1M2R(r)E(e)L1(l1)L2(l2). Presence of one or two sublobal hairs on maxillary outer lobe. Antennae of various length, composed of four segments, with Ant. IV always divided into two equal or subequal sub-segments and devoid of apical bulb. Suture zone of head when visible follows divergent lines. Trichobothrial pattern 0, 0/0, 2, 3, 3. Dorsal macrochaetotaxy oligochaetotic, polychaetotic on the collar. Macrochaetae on head present as 0-7+0-7 in area dorsalis (central mac). Th. II with a compact group of 6+6 mac accompanied by 0-4+0-4 mac anteriorly. Th. III with a group of 3+3 mac accompanied by 0-1+0-1 mac anterior-externally. Claw with 0-2 inner teeth, a pair of lateral ones and a dorsal tooth. Dens elongated with one or two rows of spines, those on external row larger, more serrated than those on internal row. Mucro of various length, 2-16 × shorter than dens, with 3-5(6) main teeth, proximal tooth sometimes with 1-5 basal toothlets.

Remarks.

The number and arrangement of trichobothria on Abd. IV allows clear separation of Troglopedetinae (3+3 trichobothria) from other Paronellidae (2+2 trichobothria). Many characters are unknown for several species of Troglopedetes , including its type species. Two characters complementary to those listed by Soto-Adames et al. (2014) are discussed below. A new set of characters present in Troglopedetes are presented below as a result of this work.

Pseudopores.

Pseudopores are arranged on tergites as in other Entomobryoidea : 1, 1/1, 1, 1, 1 from Th. II to Abd. IV. Additionally, a row of 4+4 pseudopores is constant behind the posterior row of chaetae of Abd. IV ( Deharveng, 1988a). These pseudopores are present in Cyphoderopsis ( Jantarit et al. 2013) and were reported in various number (4-10+4-10) under the name "lenticular organs" sensu Christiansen and Bellinger (1996) in Trogolaphysa ( Soto-Adames and Taylor 2013) and in T roglobius ( Cipola et al. 2016). They have also been detected in Cyphoderidae ( Jantarit et al. 2014), but not in other families of Entomobryoidea , pointing to relatedness between the cited genera and Cyphoderidae , which have led some Collembologists to consider Cyphoderidae as a subfamily of Paronellidae .

Macrochaetotaxy.

Dorsal clothing of macrochaetae is clearly oligochaetotic in the Troglopedetes species where it has been described. Pattern on Th. II includes a compact group of six chaetae (P3 complex of Soto-Adames et al. 2014) which is very obvious and constant. The same group, including 3-6 mac, is present in Trogolaphysa ( Soto-Adames 2015, Soto-Adames and Taylor 2013), and a group of three or four mac in a line is found in Cyphoderopsis ( Jantarit et al. 2013). The pattern on Th. III exhibits a group of three mac in Troglopedetes whereas Trogolaphysa shows 0-3 mac and Cyphoderopsis has none.

Dental spines.

Dens of Troglopedetes is elongated with either one or two rows of spines, those of the external row larger and more serrated than those of the internal one that are rather short and smooth. Soto-Adames et al. (2014) mistakenly stated that Troglopedetes has a single row of dental spines. In fact, species of the Mediterranean region, Africa, south-west and central Asia known so far have only one row of 8-45 dental spines, but all Thai species have two rows of dental spines (internal row with 9-45 spines, external one with fewer spines).