Schaefferia cheoha Wray, 1963

Bernard, Ernest C., 2015, Redescriptions of Hypogastruridae and Onychiuridae (Collembola) described by David L. Wray, Zootaxa 3918 (3), pp. 301-338 : 319-321

Schaefferia cheoha Wray, 1963

Fig. 12

Schaefferia cheoha Wray 1963: 103 ; Christiansen & Bellinger 1980: 194, 1998: 206; Jordana et al. 2012: 45. = Schaefferia duodecimocellata Bonet, 1945 , sensu Thibaud et al. 2004: 176 .

Specimens examined. Lectotype female (?) and 14 paralectotype juveniles (by present designation), USA, Tennessee, Sevier County, sample “Tenn. #621,” elev. 3,200 ft. (975 m), 27 October 1959, T. P. Copeland, coll.

Redescription. Body length up to 1.13 mm [up to 0.8 mm]. [Color light speckled violet in ethanol.] Ocelli 6+6 on black eye patches. Granulation consisting of minute granules with scattered larger granules. All dorsal head setae present and of similar length except setae p4 and g4 longer than other setae ( Fig. 12 A). Pronotum with three setae, most lateral seta the longest. Meso- and metanota with sensilliform setae slightly shorter than setae p5 and p6; m2 absent, m3 and m4 adjacent; p2 more anterior than p1 and p3. Mesonotal setae a3, p2, p5 and p6 and metanotal setae p2, p5 and p6 macrosetae. Mesonotum with minute rod-like microsensillum. Subcoxae I, II, and III with 1, 3, 3 setae, respectively, each subcoxa with one strong macroseta. Abdominal segments lacking m-row setae. Abdominal macrosetae as follows: on Abd. I and II p2, p6 and p7; on Abd. III p2, p4, p6 and p7 (on one specimen p4 a microseta ( Fig. 12 A)); on Abd. IV p2, p4 and p6; on Abd. V. p1 and p5; three pairs on Abd. VI. Abdominal sensilliform setae longer than half the length of neighboring p-macrosetae, becoming progressively longer posteriorly, p3 on Abd. V nearly as long as p5 ( Fig. 12 A). Seta p3 absent from Abd. II–IV. Seta p2 absent from Abd. V. Plurichaetosis absent.

Antennal segments III and IV apparently fused. Segment IV with simple spherical apical bulb and seven short, plump sensilla: five more proximal dorsal sensilla and two more distal lateral sensilla ( Fig. 12 B). Organite capitate, next to more distal lateral sensillum, microsensillum rod-like, posterior to more proximal lateral sensillum. Most dorsal and lateral setae sensilliform, with several short typical setae apically and one typical seta posterior to organite. Ventrally, Ant. IV with weakly grouped sensory field of 9–10 weakly capitate sensilla and one socketless pin seta; two longer sensilliform setae distal and proximal to pin seta ( Figs. 12 C, D). Sense organ of Ant. III with pair of small pyriform sensilla flanked by two slender, more posterior sensilla; lateral microsensillum peg-like ( Fig. 12 B). Antennal segment I with 7 setae, Ant. II with 12 setae.

Labrum with anterior edge weakly scalloped, dorsal surface granulated; setal formula 5-5-4. Maxilla not clearly seen; lamella 1 extending well past capitulum teeth, lamella 2 reaching teeth ( Fig. 12 G). Outer lobe of maxilla with one sublobal hair. Labial palpus with short, slender sensilla A–E, B longer than others ( Fig. 12 F); all guard setae present except d1 and e7; guard setae a1 and b1 lobe-like, setae b2, d2 and e2 spine-like; remaining guard setae slender, longer than sensilla; lateral papilla minute, conical. Labial palpus with 6 proximal setae.

Tibiotarsi I, II, III with 19, 19, 18 setae, respectively; clavate tenent hairs absent ( Figs. 12 H, I). Unguis with inner tooth in middle, lateral teeth absent. Unguiculus with small basal swelling and tapering, pointed apical filament not reaching inner tooth of unguis. Ventral tube with 4+4 setae ( Fig. 12 A).

Furcula with all parts separate and distinct ( Fig. 12 J). Dens length about 3 times that of mucro, with three smooth, slender setae, the basal seta slightly longer than the other two. Mucro simple, rounded apically, with weak longitudinal groove. Tenaculum with 3+3 teeth, without setae. Anal spines slender, nearly straight, very long, on prominent papillae; spines 1.5 times longer than inner unguis ( Fig. 12 A).

Remarks. Schaefferia cheoha was synonymized with S. duodecimocellata and keys to that species in Thibaud et al. (2004). The two species are quite different in chaetotaxy. Schaefferia duodecimocellata possesses m-row setae on Abd. I‒IV, while S. cheoha lacks m-setae on these segments. Therefore, S. cheoha is removed from synonymy and reestablished as a valid species.

The largest specimen was chosen as the lectotype. This specimen appears to be a female with ventral setae on Abd. V but its orientation obscures the region where the genital aperture would be. The possible juvenile status of the lectotype may raise the question of whether the lack of abdominal m-row setae is merely a juvenile characteristic. First instars of S. caeca ( Cassagnau, 1959) and S. willemi ( Bonet, 1930) lack abdominal m-setae except that S. caeca has m1 on Abd. IV ( Thibaud 1967, 1970). Later stages have additional m-setae. In S. pouadensis Delamare Deboutteville, 1945 the third instar has 3+3 m-setae on Abd. IV ( Thibaud 1970), but at least one species, S. quadrioculata ( Stach, 1939) , typically lacks m-setae on Abd. I–III ( Thibaud et al. 2004).

Figures

FIGURE 12. Schaefferia cheoha. A) Dorsal chaetotaxy. Arrow indicates p 4 as microseta. B) Third and fourth antennal segments, dorsal view. C) Third and fourth antennal segments, ventral view. Arrow indicates pin seta. D) Apex of fourth antennal segment of another specimen. Arrow indicates pin seta. E) Postantennal organ and eyes, right side. F) Labial palpus. G) Partial illustration of head of maxilla. H) Foretibiotarsus. I) Metatibiotarsus. J) Dentes and mucrones.