Honduranura centraliamericana sp. n.

Neanuridae with aspect of a yellow Neanura. 2+2 slightly pigmented big eyes. Body color yellow or orange when alive, without blue pigment, almost white in alcohol (Fig. 1). Mouthparts reduced, maxillae styliform. Sensilla S7 on Ant. IV hypertrophied, at least twice thicker than others. Clypeal and Antennofrontal tubercles fused altogether, cephalic setae A, B, E, F and G present (O, C and D absent) (Fig. 2). Two ocular setae: Ocm and Ocp. Posterior cephalic tubercles Di and De fused at each side, Di1, Di2, De1 and De2, not in crossed pattern. Dorsolateral tubercle (DL) separate, with two me and two M setae. Lateral tubercle with two M and two me, subocular tubercle with 5 setae. Thorax I with two M setae on De and one M seta on DL tubercle, without setae or tubercle on Di position. Di tubercle of Th. II and III with three setae, one M and two mi; Di tubercle on Abd. I–III with two setae, one M and one me. De tubercle with two setae one M and one me, plus ss from Th. II to Abd. III. Tubercle Di on Abd. IV with two setae M and mi, other tubercles with lateroexternal migration. Abd. V with tubercles Di, De and DL fused, with three setae and one sensorial seta ss. Four (2+2) macrosetae between the sensorial setae on Abd. IV, two (1+1) setae between sensorial setae of Abd. V. Head and body tubercles with strong subcuticular reticulation. Distal part of abdomen strongly bilobed.

Figures 1–3. 

Honduranura centraliamericana sp. n. 1 habitus on slide 2 antennofrontal + clypeal tubercle 3 dorsal chaetotaxy of head and thoracic segments I–II.

This is the only genus in the Sensillanurini tribe with clypeal and antennofrontal tubercles fused on head, dorso-internal and dorso-external tubercles fused on each side of the head, and tubercles of abdomen V fused on each side of the body. In addition, all tubercles exhibit a strong subcuticular reticulation, and dorsolateral and lateral tubercles slightly elongated.

The name of genus is after the country where the author had seen specimens for the first time and it is the type locality of the type species. Gender of genus is feminine.

Holotype: adult female; Paratypes: three adult females, one adult male and one juvenile. All the type material kept at author’s institution.

Central America: Honduras: Camayagua (14°48'39"N; 87°53'22"W). 2140 m asl. FS2A LLAMA # Wa-C03-2-all, cloud forest, samples of leaf litter. 05.v.2010, F. Soto-Adames leg.

Central America: Costa Rica: Sierra de Talamanca. Parque Nacional Tapantí (9°46'14"N; 83°47'59"W). 1200 m asl, tropical rain forest, ex rotting trunk. 19.vii.2010, J. G. Palacios-Vargas col. One female and one juvenile.

Length of holotype 2.5 mm; length range: 2.2–2.8 mm (n = 5). Color yellowish. Granulations strong, approximately 1/4 diameter of one eye. Tubercles well developed mainly on lateral and posterior part of body (Fig. 1), with strong subcuticular reticulation. Head with clypeal and antennofrontal tubercles fused with setae A, B, E, F, G present (O, C and D absent) (Fig. 2); posterior cephalic tubercles dorsointernal and dorsoexternal fused (Fig. 3). On Abd. V there is only one tubercle on each side (Fig. 4). Two kinds of dorsal body setae, macrosetae (M) 46 µm (38–60 µm) with blunt apex, mesosetae (me) with blunt apex, both slightly serrate in both sides, besides sensorial setae (ss) (30 µm). All ventral setae are smooth and acuminate; some are macrosetae and most are mesosetae.

Figures 4–7. 

Honduranura centraliamericana sp. n. 4 dorsal chaetotaxy of abdominals segments II–VI 5 dorsal antennal segments III and IV 6 chaetotaxy of pre-labrum/labrum 7 chaetotaxy of labium.

Ant. I with 9 setae, 4 dorsal slightly barbulate macrosetae on a surface with subcuticular reticulation. Ant. II with 11 setae, one of them slightly serrate. Ant. III sensorial organ with two globular sensilla in a cuticular fold, and two guard sensilla; S.g.d slightly curved, one microsensillum ventro-external. Ant. IV with hypertrofied sensilla S7; S2 like other sensilla. One clear subapical organite. Apical bulb of Ant. IV trilobed (Fig. 5).

Labrum with 4 short prelabral setae, two short basal setae and two long apical setae (Fig. 6). Labium without tuberculate seta L, organite “x” or seta A (as cited by Deharveng, 1983 for the subfamily) Seta D short; seta F much longer than E and G (Fig. 7). Eyes 2+2, large, with dark pigment. Mandibles with three teeth. Maxillae styliform. Head with clypeal and antennofrontal tubercles fused, ocular seta Ocm and Ocp in one independent tubercle, Di and De tubercles fused, DL and L tubercles independent and well developed. Head chaetotaxy in figure 3 and in Table 1. Three pairs of postlabial setae, the second one much larger and thicker than others (Fig. 7).

Legs chaetotaxy from coxae to tibiotarsi (I, II and III), respectively, as 3,7,7; 5,5,5; 10,10,10; 18, 18, and 17 setae, without capitate tenent hairs, but with setae B4 and B5 long and acuminate (Fig. 8). One ventral seta of trochanter is small and very thin. Each femur with one long ventral seta. Ungues with strong granulation but without tooth. Thoracic and abdominal chaetotaxy in Figs 3 and 4. Body chaetotaxy by half tergite is shown in Table 2.

Figures 8–12. 

Honduranura centraliamericana sp. n. 8 lateral view of tibiotarsus III chaetotaxy 9 furcular vestige (midventral region of Abd. III) 10 ventral chaetotaxy of Abd. II–VI 11 female genital plate 12 male genital plate.

Ventral tube with 4 + 4 setae, the two distal setae subequal in size, basal setae are different, one is larger. Furcal vestige with four mesosetae and four apical microsetae in the apex of a small tubercle (Figs 9, 10). Female genital plate with 6 + 6 pregenital, 28 circumgenital and two eugenital setae (Fig. 11), genital plate of the only male studied with 6 + 6 pregenital, 16 circumgenital and 2 + 2 eugenital (Fig. 12), but it should be 6 + 6, 22, and 4 + 4 respectively. Each lateral anal valve with subcuticular reticulation, 11 setae and 2 microsetae. Ventro-internal tubercle of Abd. V well-developed and with strong subcuticular reticulation, one macroseta and three mesosetae.

The new species is named H. centraliamericana sp. n. for its distribution in Central America (Honduras and Costa Rica), but it might be even more widely distributed, as the two localities are approximately 800 km from each other.

This species has the unique characters of this new genus: the fusion of clypeal and antennofrontal tubercles and of dorsointernal and dorsoexternal tubercles on head. Additionally, the presence of only one tubercle on each side of the abdominal segment V is unique among Sensillanurini. The new species has more abundant head chaetotaxy than members of Americanura and Palmanura, including the antennofrontal, dorsolateral and lateral cephalic tubercles, and Th. I which has no Di seta, against one in all species of the genus Sensillanura (Palacios-Vargas and Catalán 2010). The presence of nine setae on Ant. I have been cited in other member of the Neanurinae (Deharveng 1981), here, there are five dorsal slightly barbulate macrosetae on a surface with subcuticular reticulation like in the Neanura, Monobella and Neanurella species which exhibit this character, and which belong to different evolutionary lineages; the 6 + 6 pregenital setae is also a character unique in the tribe. The furcal vestige of the new species is like that of Sensillanura, but more developed, as a small tubercle similar to that of Morulina species, with mesosetae and microsetae.

Variation: The ag setae in females varies from 5-6 pairs, and circumgenital ones from 15 to 28 setae. One teratologic specimen lacks left tubercle of abdominal segment VI. Some of the mesosetae on Di tubercle of Th. II and III are very thin and smooth and can be overlooked. The juvenile paratype has ten setae on anal valve instead of eleven. The specimens from Costa Rica have the dorsal macrosetae and mesosetae acuminate.