Campylothorax cubanus Gruia, 1983

Felipe N. Soto-Adames, 2016, Chaetotaxy of first-instar Campylothorax sabanus (Wray), and description of three new Campylothorax species from Hispaniola (Collembola, Paronellidae), Journal of Natural History 50 (25), pp. 1583-1612 : 1605-1608

Campylothorax cubanus Gruia, 1983

Figures 12 – 13

Material examined

Dominican Republic: one specimen slide-mounted and one in alcohol, Elias Pina, Sierra de Neiba, 9.1 km WSW Hondo Valle, 18°41'38.0754''N, 71°46'56.0274''W, 515 m elevation, wet montane forest with pines, yellow pan trap, 25 June 2003, sample DR31262, J. Rawlins, C. Young, R. Davidson, C. Núñez, P. Acevedo, M de la Cruz. Haiti: Miragoane, January 1974, R. Bell, two specimens slide-mounted and 16 in alcohol.

Size. Up to 2.3 mm.

Colour pattern. Background colour light brown or white ( Figure 12 A, B); light purple or blue pigment present on antennae, head, mesothorax, legs, posterior margin of metathorax and lateral margin of Abd. 1 – 4. Dark purple pigment covering most of middle section of Abd. 3, and middle section and posterior margin of Abd. 4; U-shaped band on Abd. 4 sometimes broken in middle ( Figure 12 C).

Head. Head with seven Mc along antennal margin and four other Mc along eye patch inner margin; with one unpaired (A0) and seven paired (A2, A3, A5, S2, S3, S4, S5) anterior Mc; posteriorly with one Mc (Pa5). Pre-labral chaetae smooth. Maxilla lamellae 1 and 2 as in C. notidanus sp. nov. Lateral appendage of labial papilla E long, reaching tip of papilla. Number of chaeta along cephalic groove unclear, apparently six.

Body. Body Mc as 74/0241+7+0+6. Th. 2 dorsally flat; Th. 3 rounded, relatively short, just covering anterior margin of Abd. 1 ( Figure 13 A). Thoracic Mc as in C. sabanus: Th. 2 with seven Mc in p3 complex and Th. 3 with four Mc in p2 – 3 complex ( Figure 13 A). Abd. 3 lateral mesochaetae as in C. notidanus sp. nov. Inner section of Abd. 4 with anterior triangle formed by paired A1 and medial unpaired Mc; inner posterior Mc 6 + 6 as in Figure 13 B: Mc A3 well posterior of pseudopore; organisation of inner posterior Mc variable (cf. Figure 13 B, C). Lateral section of Abd. 4 with six large Mc (E4, E2, E3, F1, F2, F3); Mc E4 posterior to D2; microchaetae D2 and T6 enlarged; posterior chaetae 20 + 20.

Legs. Trochanteral organ with up to 27 chaetae. All tenent hairs spatulate. All claws with three inner teeth and three outer teeth: basal inner teeth subequal, inserted on basal half in fore and middle legs, inserted on middle quarter of hind legs; unpaired tooth inserted on distal half of all legs; lateral teeth short but easily observed, inserted on basal quarter of outer edge; dorsal tooth short and inconspicuous, clearly seen only in dorsal perspective. Unguiculus of all legs truncate, with one inner tooth; unguiculus on fore and middle legs shorter than on hind legs.

Furcula. Mucro typical for genus, 1.7 – 2.4 times as long as inner edge of hind claw.

Remarks

Determination of Hispaniolan populations as C. cubanus is provisional, based on colour pattern. The characters used here to distinguish C. cubanus from C. sabanus and C. dominicanus sp. nov. (see above), which could potentially distiguish Cuban from Hispaniolan populations, are yet to be described for the Cuban form. However, irrespective of whether or not the combination C. cubanus should be used for Hispaniolan populations, it is clear that the form described here is very similar to C. sabanus , C.

dominicanus sp. nov. and C. cassagnaui . Separation of C. cubanus , in the present sense, from C. dominicanus sp. nov. is discussed above. As explained by Mari Mutt (1987) the original separation of C. cubanus from C. sabanus was based on misinterpretations of the chaetotaxy of C. sabanus presented in Mitra and Dallai (1980). The description of C. cubanus presented here confirms the similarity between the two Antillean species. The only characters allowing separation of C. cubanus from C. sabanus are colour pattern (absence in C. cubanus of the inverted W on anterior margin of Abd. 4, combined with the presence of a regular, medial U-shaped band; C. sabanus has the inverted W mark and the medial band is irregular, most often present as unconnected spots), the number of lateral mesochaetae on Abd. 3 (three, two in C. cubanus , only three in C. sabanus – cf. Figures 2 D and 6A), and the number of inner teeth in the unguis (three in C. cubanus and four in C. sabanus ).

Campylothorax cubanus is also similar to C. cassagnaui from Rio de Janeiro, but the Brazilian species appears to carry only four inner posterior Mc on Abd. 4 ( Cassagnau 1963). Further analysis of fresh specimens of C. cassagnaui is needed to clarify the relationship between the Brazilian and Antillean forms.

Figures

Figure 2. Campylothorax sabanus dorsal chaetotaxy. (A) Second abdominal segment, first instar. (B) Second abdominal segment, adult. (C) Third abdominal segment, first instar; arrow points at supernumerary chaeta of uncertain homology present in one specimen. (D) Third abdominal segment, adult. Symbols represent pseudopores, scales, bothriotricha and macro-, meso- or microchaetae as explained in the Methods section. v-shaped symbols represent primary scales; triangles represent fan-shaped ciliate microchaetae.

Figure 12. Campylothtorax cubanus. (A) Habitus; individual from Haiti. (B) Habitus; individual from Dominican Republic. (C) Detail of fourth abdominal segment pattern; individual from Dominican Republic.

Figure 13. Campylothorax cubanus. (A) Thorax and first abdominal segment; arrow points anteriorly; homology of thoracic Mc as in C. sabanus. (B) Latero-internal chaetotaxy of fourth abdominal segment; individual from Dominican Republic. (C) Inner Mc; individual from Haiti.