Allonychiurus shandongensis, Sun & Li, 2015

Sun, Xin & Li, Yu, 2015, Thalassaphorurini (Collembola: Onychiuridae) in Shandong Province, China, with description of two new species, Florida Entomologist 98 (2), pp. 697-703 : 698-703

Allonychiurus shandongensis sp. nov. ( Figs. 13–25 )

MATERIAL EXAMINED

HOLOTYPE male, CHINA, Shandong Province, Laiwu City, Fangxia Town, Wulongkou Village (36.2154°N, 117.4886°E), 1 Apr 2014, soil of the greenhouse planting with P.ostreatus, Xin Sun coll. (SDLW-140401) . PARATYPES 7 females and 1 male, same data as holotype .

OTHER MATERIALS 6 females, CHINA, Shandong, Tai’an City (36.1965°N, 117.1793°E), 31 Mar 2014, soil of the greenhouse planting with P. ostreatus, Xin Sun coll. (SDTA-140331) .

DESCRIPTION

Body white in alcohol. Length of body 0.75–0.98 mm in females, 0.75–0.78 mm in males; holotype 0.75 mm. Shape of body cylindrical with anal spines on papillae. Anal spines 0.8 times as long as inner edge of hind unguis.

Pso formula 33/233/33343 dorsally and 11/000/01110 ventrally ( Figs. 13, 18 ). Subcoxae 1 of legs I–III with 2 pso each. Psx formula 00/000/100000 ventrally and psx absent dorsally ( Figs. 13, 18 ). Subcoxae 1 of legs I–III without psx. Psp formula 00/011/111100 dorsally and 00/111/0001 m 00 ventrally ( Figs. 13, 18 ).

Head. Antennae as long as head. Length ratio of Ant. I: II: III: IV about 1: 2: 2: 2.5. On Ant. IV subapical organite with globular apex, 2 S-chaetae differentiated, basolateral ms above the 2nd proximal row of chaetae ( Fig. 17 ). Ant. III sensory organ consists of 5 papillae, 5 guard chaetae, 2 small rods, and 2 smooth sensory clubs; lateral ms just behind sensory organ ( Fig. 16 ). Ant. II with 13–14 chaetae. Ant. I with 9 chaetae. Antennal base well marked. PAO with 10–11 compound vesicles arranged in 2 rows along axis of organ ( Fig. 14 ). Dorsally on head 4+4 p-chaetae present between 2 posterior pso, p1 anterior to others ( Fig. 19 ). Mandible with strong molar plate and 4 apical teeth. Maxilla bearing 3 teeth and 6 lamellae. Maxillary palp simple with 1 basal chaeta and 2 sublobal hairs. Labral chaetae 4/142. Labium with 6 proximal, 4 basomedian (E, F, G, and f), and 6 basolateral (a, b, c, d, e, e’) chaetae. Labial type AC, papillae A–E with 1, 4, 0, 3, and 2 guard chaetae, respectively ( Fig. 15 ). Postlabial chaetae 4+4 along ventral groove ( Fig. 20 ).

Body chaetotaxy. S-chaeta slightly distinguishable from ordinary chaeta, distributed as 11/011/222121 dorsally and 11/000/000100 ventrally ( Figs. 13, 18 ). Coxae of legs I, II, and III with 0, 0, and 1 S-chaeta, respectively. Tiny and blunt ms, present on Th. II and III ( Fig. 13 ). Th. I tergum with 5+5(6) chaetae. Th. II – Abd. III terga with 3+3 chaetae along axial line ( Fig. 13 ). Abd. IV tergum with unpaired chaeta m0, Abd. V tergum with chaeta a0, Abd. VI tergum with chaetae a0 and m0 (we found only 1 specimen with two a1 instead of a0) ( Fig. 13 ). Th. I, II, and III sterna with 0+0, 1+1, and 1+1 chaetae, respectively .

Appendages. Subcoxae 1 of legs I, II, and III with 4, 4, and 4 chaetae, subcoxae 2 with 1, 4, and 4 chaetae, respectively. Coxae of legs I, II, and III with 3, 11, and 12 chaetae, respectively, trochanters with 9 chaetae each, and femora with 14, 16, and 14 chaetae, respectively. Tibiotarsi of legs I, II, and III with 18 (1, 8, 9) each. Unguis without teeth. Unguiculus as long as inner edge of unguis, without inner basal lamella ( Figs. 21, 22 ). Ventral tube with 6+6 distal chaetae and 2+2 basal chaetae, without anterior chaetae. Furca reduced to finely granulated area, with 4 small dental chaetae in 2 rows posteriorly and 1 manubrial row of chaetae ( Fig. 23 ).

Female genital plate with 10–13 chaetae and male with 22–26 ( Figs. 18 , 25 ). Male organ present, 2+2 thickened chaetae on distal ventral tube and 3+3 thickened chaetae on the genital plate. Anal valves with numerous acuminate chaetae; each lateral valve with chaetae a0 and 2a1; upper valve with chaetae a0, 2b1, 2b2, c0, 2c1, and 2c2 ( Fig. 24 ).

DERIVATIO NOMINIS

The species name is derived from the name of the province (Shandong Province) where the species was found.

REMARKS

Allonychiurus shandongensis sp. nov. should belong to the “ volinensis -group,” which was established by Babenko et al. (2011) as having small body size (less than 1.0 mm) and smooth sensory clubs on Ant. III sensory organ; but it can be distinguished easily from others (except A. asiaticus Babenko, 2011 ) as having 5 papillae on Ant. III sensory organ. The new species differs from A. asiaticus by the number of pso on Abd. IV sternum (1+ 1 in A. shandongensis sp. nov. and 2+ 2 in A. asiaticus ), presence of posterior S-chaeta on head (absent in A. asiaticus ), absence of chaetae on Th. I sternum (present in A. asiaticus ), absence of anterior chaetae on ventral tube (1+ 1 in A. asiaticus ), and number of chaetae in distal row of tibiotarsi (9 in A. shandongensis sp. nov. versus 7 in A. asiaticus ). The new species is also close to the Chinese species A. songi as having the same dorsal pso formula (32/233/33343), pso on subcoxae 1 of legs I–III (2 each), dorsal S-chaetae formula (11/011/222121), unpaired axial chaetae on Abd. IV–VI terga (m0, a0, a0, and m0), number of chaetae in distal row of tibiotarsi as 9, number of chaetae on ventral tube (6+6 distal chaetae and 2+2 basal chaetae, without anterior chaetae), and position of male ventral organ (situated on ventral tube and genital plate). These species can be distinguished easily by the number of p-chaetae between 2 inner posterior pso on head (4+ 4 in A. shandongensis sp. nov. and 3+ 3 in A. songi ), pso on Abd. IV sternum (1+ 1 in A. shandongensis sp. nov. and 2+ 2 in A. songi ), papillae on Ant. III sensory organ (5 in A. shandongensis sp. nov. and 4 in A. songi ), and chaetae on Th. I sternum (absent in A. shandongensis sp. nov. and 1+ 1 in A. songi ).

Figures

Figs. 13–18. Allonychiurus shandongensis sp. nov. 13. Dorsal chaetotaxy of body; 14. PAO; 15. Labium; 16. Papillae, sensory rods, and sensory clubs of Ant. III sensory organ; 17. Antenna; 18. Chaetotaxy of Abd. I–VI sterna. Scale bars: 0.1 mm (Figs. 13, 17–18), 0.01 mm (Figs. 14–16).

Figs. 19–25. Allonychiurus shandongensis sp. nov. 19. Dorsal chaetotaxy of head; 20. Ventral chaetotaxy of head; 21. Distal part of leg II; 22. Distal part of leg III; 23. Chaetotaxy of Abd. IV sterna; 24. Anal valves;25. Central part of Abd. V sternum with female genital plate. Scale bars: 0.1 mm (Figs. 19, 20, 23), 0.01 mm (Figs. 21–22, 24–25).