Cyphoderus manuneru Bernard, Soto-Adames & Wynne

Bernard, Ernest C., Soto-Adames, Felipe N. & Wynne, J. Judson, 2015, Collembola of Rapa Nui (Easter Island) with descriptions of five endemic cave-restricted species, Zootaxa 3949 (2), pp. 239-267 : 259-263

Cyphoderus manuneru Bernard, Soto-Adames & Wynne , n. sp.

Figures 7 B, 13‒15

Material examined. CHILE, Rapa Nui, Maunga Hiva Hiva region, holotype male, Cave Q15-070, opportune collection on decomposing wood 50 m from cave entrance, 0 6 April 2011, J. Wynne, coll.

Description. White. Eyes absent. Length 1.01 mm, head diagonal 0.26 mm. Antennal segments III and IV missing. Head and body scaled, ventral side of head with 2+2 scales ( Fig. 13 B); Antennal segments I and II with a few scales ( Figs. 13 E, G); most scales oblong, rounded apically, with dense, evenly spaced barbs, without outer fringe; some scales on head and antennae apically bilobed ( Figs. 13 G, 14B, C).

Antennal segments III and IV broken off. Ant. I dorsally with 3 small, smooth microsetae and 8 ciliate mesosetae ( Fig. 13 E), ventrally with 17 smooth microsetae of various lengths and 4 ciliate mesosetae ( Fig. 13 F). Dorsal side with 3 scale scars, ventral side without evidence of scales. Ant. II dorsally ( Fig. 13 G) with 5 scales in basal half, minute proximo-basal microseta, one lateral and 4 distal microsetae, 3 apical sensilla, and 13 ciliate mesosetae. Ventrally, Ant. II without scales, with 10 microsetae of which two are longer than the others, one microseta adjacent to a smooth, pointed seta of similar length and 15 ciliated setae, several of them shorter than the others ( Fig. 15 H).

Labrum with 4/5-5-4 smooth setae ( Fig. 13 E), anterior margin not visible. Outer lobe of maxilla with one sublobal hair. Head of maxilla somewhat obscured but with six lamellae ( Fig. 13 K), lamella 1 tapering and extending past capitulum teeth, lamella 2 similar but shorter, lamella 3 short, lamella 4 extending horizontally, lamellae 5 and 6 small, narrow. Left mandible with 4 teeth, right mandible with 5 teeth. Labial palp ( Figs. 13 I, J) with sensilla A–E, sensilla B, D and E extending past apices of longest guard setae. Thirteen guard setae present. Guard a1 small, oval, set in weak depression; guards b1, b2, d1, d2 and e2 long and relatively stout, most with distinct bases ( Fig. 13 J); lateral process (lp) extending past base of sensillum E, slightly enlarged apically, pointed at tip. Four proximal setae. Base of labium with smooth setae M, E, L1 and A1‒5, seta L2 minute ( Fig. 13 B).

Most head setae consisting of short, smooth, acuminate microsetae ( Figs. 13 A, B, E); body segments mostly with small mesosetae. Prelabral setae smooth and acuminate, other frontal setae ciliate; frontal seta F0 reduced to minute projection. Each cephalic bothriotrix with associated ciliate microseta. Lateral cephalic mesosetae long, strongly ciliated ( Fig. 13 C). Head with one median seta corresponding to S0. Ventral side of head with four pairs of medial setae, the posterior pair ciliated ( Fig. 13 B).

Macrosetal formula 00/00020. Mesonotum dorsally with collar of short, pointed setae, 3+3 anterior setae and 3+3 posterior setae ( Fig. 13 A); right side with m-seta, lacking on left side. Sensilla S1 and S2 present, S1 near antero-lateral margin, S2 mid-lateral ( Fig. 13 D). Metanotum with single row of 4+4 setae, Abd. I with 3+3 setae, Abd. II and III without setae between pseudopores. Second abdominal segment bothriotrichal region with 5 ciliate microsetae, smooth setae absent ( Fig. 15 A). Outer bothriotrichal field of Abd. III with 5 ciliate and 2 smooth microsetae, inner field with 3 ciliate and one smooth microsetae ( Figs. 15 B, C). Fourth abdominal segment with inner macroseta B4 and outer macroseta E3. Mesosetae A4, A5 and T7 ciliate, their associated microsetae smooth and narrowly rounded apically ( Figs. 13 A, 14E). Seta C2 absent. Seta De3 half the length of neighboring bothriotrix, smooth. Anterior bothriotrichal field with 5 ciliated microsetae ( Fig. 15 D), posterior bothriotrix associated with macroseta E3 and with 4 ciliated microsetae, one of which is minute ( Fig. 15 E). Fourth abdominal segment with 7+8 posterior setae. Fifth abdominal segment with 5+5 dorsal mesosetae.

Legs without scales; tenent hair pointed, smooth. Setae of legs consisting of stout, spinulate or strongly ciliate mesosetae, smooth setae absent. Fore and middle ungues ( Fig. 15 G) with lateral and outer teeth forming a weak tunica; inner edge with 3 teeth, basal pair with one tooth much larger, wing-like, basal paired tooth minute; distal unpaired tooth larger than small basal tooth; unguiculus truncate distally, outer wing present. Hind foot ( Fig. 15 H) similar but claws larger; unguis with doubled lateral teeth, one inner tooth and large inner wing extending past unguiculus, which is truncate and winged. Trochanteral organ consisting of 10 small, smooth, stout pointed setae arranged in two irregularly horizontal rows of five and a proximal seta ( Fig. 15 F). Ventral tube not clearly seen. Tenaculum arms each with four teeth, corpus with one seta. Manubrial plaque with 2+2 pseudopores. Dorsal surface of dens ( Fig. 15 I) with about 7 ciliate setae and at least 7 broad, densely denticulate or ciliated scales; apex of dens with 2 long, robust scales, one about half length of mucro, other nearly as long as mucro, surfaces densely covered with ciliate denticles that also form a fringe; each dens with two finely ciliate interior basal setae and one smooth distal exterior seta. Ventral surface of dens ( Fig. 15 J) covered with slender, smooth, hyaline scales. Mucro straight, nearly half as long as dens, with strong apical and anteapical teeth and minute, acutely pointed external tooth almost level with anteapical tooth; fine membranes ending at external and anteapical teeth ( Figs. 14 F‒H, 15I, J). Genital plate round with linear medial aperture, without associated setae.

Labral, antennal and ventral tube pseudopores not seen. Mesonotum, metanotum and Abd. I‒IV each with one pair of dorsal pseudopores, those of Abd. II displaced laterally; body pseudopores usually with narrow grooves in obliquely longitudinal orientation ( Fig. 14 D). Posterior margin of Abd. IV with 1+2 pseudopores in posterior setal field ( Fig. 13 A). Manubrial pseudopores not seen.

Etymology. The species was named by combining two Rapanui terms, manu and neru. Manu is Rapanui for “bug” or “insect.” Neru is the name used for Rapanui girls who, historically, were secluded in caves so they would acquire a fair complexion ( Fischer 1994), thus, “pale insect”. Because all of these Collembola are believed to be restricted to caves (i.e, isolated from surface-dwelling arthropod communities), naming one after the Rapanui youth who remained in caves to attain a fair complexion is appropriate.

Remarks. Cyphoderus manuneru n. sp. is a member of the bidenticulati -group of Cyphoderus , possessing two well-developed teeth on the mucro ( Delamare Deboutteville 1948). The problems with identification of Cyphoderus in this group were summarized succinctly by Jantarit et al. (2014), revolving partly around the contradictory redescriptions of the generotype, C. albinus Nicolet, 1842 . Szeptycki (1979) illustrated the developmental chaetotaxy of C. albinus collected from ant nests in Poland. Jantarit et al. (2014) described two new Thai species ( C. songkhlaensis , C. khaochakanus ), introduced several new morphological characters, and clearly illustrated the chaetotaxic pattern of all segments. These two species must be considered the first adequately described species in the bidenticulati -group; lack of such details for previously described species is a serious impediment to identification of members of this genus described earlier. The labral setae of C. manuneru n. sp. are smooth while those of the two Thai species are ciliate. Tenent hairs are pointed on C. manuneru n. sp., whereas those of the Thai species are spatulate. Setae A4 and A5 of Abd. IV on C. manuneru n. sp. are ciliate and their accessory microsetae are smooth; the Thai species have A4 and A5 smooth and their accessory microsetae ciliate.

Figures

FIGURE 7. Lateral views of whole specimens. A) Coecobrya kennethi Jordana & Baquero. B) Coecobrya aitorererere n. sp. C) Pseudosinella hahoteana n. sp. D) Seira manukio n. sp. E) Lepidocyrtus olena Christiansen & Bellinger. All scales 200 Μm. Images 7 A, C and D were previously published in BioScience, 64, 711 ‒ 718 (2014).

FIGURE 13. Cyphoderus manuneru n. sp. A) Dorsal chaetotaxy of head and body. B) Ventral cephalic chaetotaxy. C) Mesochaetae. D) Lateral edge of mesonotum. E) Labrum, anterior region of head, and dorsal view of Ant. I. F) Ventral view of Ant. I. G) Dorsal view of Ant. II. H) Ventral view of Ant. II. I) Labial palpus. J) Labial papillae E (left) and B (right) showing guard seta bases. K) Head of maxilla.

FIGURE 14. Cyphoderus manuneru n. sp. A) Labial palpus, arrow indicates lateral process on sensillum E. B) Oval head scale. C) Bilobed head scales. D) Pore on Abd. III with associated grooves. E) Ciliated mesoseta A 4 and associated smooth microseta of Abd. IV. F ‒ H) Sublateral, dorsal, and lateral views of mucrones, respectively. Scales are in Μm.

FIGURE 15. Cyphoderus manuneru n. sp. A ‒ E) Abdominal sensory fields, left side, refer to Fig. 13 A. A) Abd. II. B) Abd. III, outer field. C) Abd. III, inner field. D) Abd. IV, anterior field. E) Abd. IV, posterior field. F) Trochanteral organ of hind leg. G) Forefoot complex. H) Hind foot complex. I) Dens and mucro, dorsal view, with enlargement of smaller terminal scale-like seta. J) Dens and mucro, ventral view.