Trogolaphysa dimorphica, Soto-Adames, Felipe N., 2015

Soto-Adames, Felipe N., 2015, The dorsal chaetotaxy of first instar Trogolaphysa jataca, with description of twelve new species of Neotropical Trogolaphysa (Hexapoda: Collembola: Paronellidae), Zootaxa 4032 (1), pp. 1-41 : 14-16

Trogolaphysa dimorphica sp. nov.

Figs 3 B, 7A–G, Table 1

Etymology. The epithet refers to the variation in chaetotaxy of Abd. 4 and distribution of inner teeth of unguis in male and females.

Material examined. Holotype female, in preparation. MEXICO, Chiapas, Cacahuatan, Finca Guatemoc, Quinine grove, 975 m, Berlese sample leaf mold, 3–4.viii.1950, C. & M. Goodnight coll., INHS 579,843; 1 female and 1 male paratypes in preparation, and 11 juveniles in alcohol with same collection information as holotype.

Description. Size up to 2.3 mm.

Color pattern. Background color light brown, with granules of light blue pigment scattered on head and terga of Th. 3–Abd. 3; hind coxae more darkly pigmented than terga; distal margin of Ant. 1, all of Ant. 2–4 and tibiotarsi evenly light blue ( Fig. 3 B)

Head. Antennae up to 3.0x as long as head. Subapical sense organ with guard sensillum large and apically truncate, sensillar pit apparently absent. Sensilla in sense organ Ant. 3 normal rods. Eyes 6–8, eyes G and H greatly reduced, seen only in the largest individual ( Fig. 7 A), EOS extra ocular structure) clearly marked; eye valley with 4 ciliate chaetae. Head dorsally ( Fig. 7 A) with 5 anterior (A0, A2, A3, M2, S3) and 2 posterior (Pa5, Pm3) macrochaetae; one individual with only 2 anterior (A0, A2) macrochaeta. Pre-labral chaetae ciliate. Labral chaetae smooth. Spines on distal margin of labrum minute, separated. Labial triangle formula as M1M2rEL1L2A1–5; r stout and smooth all other posterior chaetae ciliate. Post-labial field with 6-7 chaetae between columns I and O.

Body. Body macrochaetae (6–7)3/024(3–4)+0+(7–9). Mesothorax ( Fig. 7 B) with 1 anterior (a5) and 5–6 posterior (p3 complex) macrochaetae. Metathorax with 3 macrochaetae; socket of chaeta a4 enlarged in holotype. Abd. 1 chaeta a6 present. Abd. 4 in females ( Fig. 7 C) with inner macrochaetae A3, A5, B4 and B5 present; B4 absent in male ( Fig. 7 D); A3 anterior to T2; A5 and B4 (when present) inserted near each other and closer to pseudopore than to B5; 5–7 lateral macrochaetae present, supplementary macrochaeta E2p present only in holotype, macrochaeta F2 absent in male. Abd. 4 posterior chaetae 14–15+14–15.

Legs. Trochanteral with at least 18 chaetae. Metathoracic claw complex as in Figs. 7 E–F: tenent hair spatulate on all legs, 1.3x as long as unguiculus; claws with 3 inner teeth, one basal tooth slightly larger than other, unpaired tooth as long as shortest basal tooth; inner teeth spread in females as 38%, 39%, 68% ( Fig. 7 E), in male as 38%, 41%, 50% ( Fig. 7 F). Dorsal and lateral teeth ending on basal quarter of unguis. Unguiculus lanceolate, posterior edge serrate in females, smooth in male.

Furcula. Dens with 2 rows of ciliate spines: inner row with 24–30 spines; outer row with 18–23 spines. Mucro with 4 sequential teeth ( Fig. 7 G); square to subrectangular in shape, 2.0–2.3x as long as width of distal end of dens; in females, mucro 0.84x as long as inner margin of metathoracic unguis, in male mucro 1.10X metathoracic unguis.

Remarks. Trogolaphysa dimorphica sp. nov. is unique among Neotropical species with known chaetotaxy in having 6–8 eyes, 5 anterior head macrochaetae in the particular combination A0, A2, A3, M2, S3, in having 3 metathoracic macrochaetae and Abd. 4 macrochaeta B4 (when present) inserted closer to A5 and the pseudopore than to B5. Female Trogolaphysa dimorphica sp. nov. are most similar to T. clarencei sp. nov., but differ in color pattern (Ant. 1 basally unpigmented and leg pigment restricted to tibiotarsi in T. dimorphica sp. nov., whereas in T. clarencei sp. nov. Ant. 1 and all leg segments are uniformly pigmented, cf. Figs. 3 B and 3E); and the relative insertion of macrochaeta B4 on Abd. 4 (cf. Figs. 7 C and 11F). Two other Neotropical species with 6–8 eyes carry 3 metathoracic macrochaetae ( T. giordanoae Soto-Adames & Taylor, 2013 and T. octosetosa sp. nov.) but both can be separated from T. dimorphica sp. nov. by the number of anterior head macrochaetae, number of Abd. 4 macrochaetae and number of inner ungual teeth as shown in Tables 3–4 . All other species with 3 macrochaetae on Th. 3 are blind troglomorphs. The female with reduced head and Th. 2 macrochaetae (see below) is most similar to T. carpenteri ( Denis, 1925) sensu Yoshii 1988 ( Table 4 ), but T. carpenteri has smooth prelabral chaetae, whereas in T. dimorphica sp. nov. the prelabral chaetae are ciliate. The dorsal chaetotaxy of the body remains unreported for T. carpenteri .

Collectively, the individuals examined show variation in number of head macrochaetae (2 or 5), p3 complex macrochaetae on Th. 2 (5 or 6), Abd. 4 inner macrochaetae (3 or 4), and presence or absence of Abd. 4 lateral macrochaetae E2p and F2. These are some of the most important characters currently used to diagnose Trogolaphysa species. At first it was unclear if this represented a species different from T. marielouiseae sp. nov., as both species were collected in the same event. However, the presence of 3 macrochaetae on Th. 3 in T. dimorphica sp. nov. unambiguously separates the two forms. Some differences in chaetotaxy (presence or absence of Abd. 4 macrochaetae B5 and F2) are attributable to sexual dimorphism (hence the epithet). The reduced number of head (only A0 and A2 present) and Th. 2 (5 instead of 6) macrochaetae in the smaller female may be attributed to teratology, trauma, or it may represent a different species.

Figures

FIGURE 3. Trogolaphysa spp., habitus. A, T. stannardi sp. nov.; B, T. dimorphica sp. nov.; C, T. laterolineata sp. nov.; D, T. marielouisea sp. nov.; E, T. clarencei sp. nov.; F, T. entreriosensis sp. nov.; G. T. trioculata sp. nov.

FIGURE 7. Trogolaphysa dimorphica sp. nov. A, Dorsal chaetotaxy of head, EOS is the external expression of the ' extra ocular structure'; B, Chaetotaxy of thorax 2 – 3, insets show variation in mesothoracic macrochaetae number, and organization of inner metathoracic chaetae; C, Dorsal chaetotaxy of abdomen 4 in adult female; D, Dorsal chaetotaxy of abdomen 4 in adult male; E, Female hind claw complex; F, Male hind claw complex; G, Mucro.