Imadateiella sharovi ( Martynova, 1977 )

Shrubovych, Julia, 2014, Identification and character analysis of the Acerentomidae (Protura) of the northeastern Palearctic (Protura: Acerentomidae), Zootaxa 3755 (2), pp. 136-164 : 143-149

Imadateiella sharovi ( Martynova, 1977)

Figs. 11–36 , Table 3

Acerella sharovi Martynova 1977 : p. 164. Imadateiella sharovi Imadaté 1981 : p. 144.

Diagnosis. Imadateiella sharovi is characterized by possession of 4+4 A -setae on the metanotum, presence of head seta d6, presence of seta P1a and lack of seta P3a on tergites II–VII, presence of seta Pc on sternites VI and VII, long foretarsal sensillum a and short sensilla b and c with c being shorter than b, and by long, setiform seta β1 on the foretarsus.

Material examined. Holotype female and 3 paratype females, in litter under lichens ( Cetraria sp.) and in turf stratum under Lycopodium sp. and Empetrum sp. on slopes in the zone of dwarf pine, Snezhnaya dolina (= Snow Valley), 24 km west of Magadan Town, 18.IX.1974, coll. D. Berman ( Fig. 1 , Site 8). Type specimens are preserved in the Zoological Institute of the Russian Academy of Sciences, St. Petersburg, Russia. Other material is preserved in SMNH: 7 females, 2 males, 2 preimagoes, in litter on slopes with Pinus sp., Betula sp. and Larix danurica , field station “Aborigen”, Kolyma River, Magadan district, 25.VII.1979, coll. V. Behan.

Redescription. Head setae short, seta d6 present, setae l3 and sd4 setiform, labrum slightly protruded ( Figs. 11, 12 ). Head with frontal pore (fp) and pair of clypeal pores (cp). Pseudoculus round, small, with short posterior extension, PR = 20–22 ( Fig. 12 ). Maxillary palpi short, basal sensilla short, slender, equal in length ( Fig. 13 ). Labial palp with terminal tuft of setae and slightly expanded basal sensillum ( Fig. 14 ). Maxillary gland with distinctly granulated calyx; large, vesicle-like dilation posterior to calyx and distinct, simple posterior dilation, CF = 5.6–6.1 ( Fig. 15 ).

Foretarsus lacking sensillum b’; sensillum t1 filiform, t3 leaf-like, other sensilla slender and short ( Figs. 16, 17 ). Sensillum d situated nearer to e than to c; a’ close to level of t2. Relative length of sensilla: t3 <e <g <c <b <t1 <(t2 = d) <a’ <(a = c’) <f. Setae β1 and δ4 setiform, subequal to δ1 length. Claw with small inner tooth, empodial appendage short. BS = 0.5–0.8, TR = 2.4–2.7, EU = 0.1–0.2. Two pores present near bases of sensilla c and g.

Body chaetotaxy as in Table 3 . Nota with short setiform setae P1a and P2a ( Fig. 18 ). Length ratio of P1: P1a: P2 about 3:1:4. Seta P2a situated nearer to P3 than to P2. Mesonotum with pores sl and al, metanotum with pores sl only. Prosternum without pore, mesosternum and metasternum with sc pore situated anterior to level of setae M (one specimen with double sc pores on mesosternum) ( Figs. 24, 25 ). Setae M2 on prosternum and A2 on all thoracic sternites shorter than other setae, setiform ( Fig. 26 ).

Dorsal Ventral Setae A5, P3 and P4 shorter than accessory setae P1a and P2a on tergite I ( Fig. 19 ). Lineation on tergites IV– VI with single line in anterior part of tergites ( Fig. 20 ), tergite VII with two distinct lines ( Fig. 21 ). Accessory setae on tergites I–VI setiform, slightly longer than tergite VII setae, 14 and 12 µm, respectively. Pores psm present on tergites I–VI, psl absent, al present on tergites II–VII, al on tergite VII not surrounded by teeth ( Fig. 33 ).

Abdominal legs with 4, 2, 2 setae ( Figs. 27, 28 ). Setae of abdominal legs II and III nearly equal in length, 14 and 15 µm, respectively. Sternites I–III with short ciliated line in anterolateral region ( Figs. 27, 28 ), sternite IV with line in anterior region, sternites V–VII with two distinct lines ( Figs. 29, 30 ). Sternal accessory setae slightly shorter ( Fig. 32 ) than those on tergites I–VI ( Fig. 31 ); on segment VII accessory setae equal, 12 µm long. Sternite I with 1+1 sal pores ( Fig. 27 ), sternites II–V with spm pore, sternite VI without pores and sternite VII with pore sam on the second transverse line ( Figs. 28–30 ).

Abdominal tergite VIII with row of granules in anterior position ( Fig. 22 ), sternite with two rows ( Fig. 36 ). Striate band well developed with distinct striae. Margin of comb VIII with 10 small teeth ( Fig. 34 ). Pore psm on tergite VIII with accompanying teeth. Hind margin of laterotergites and sternites smooth ( Fig. 36 ). Posterior margin of tergite X and XI with very fine serration. Setae 1 and 1a on tergite IX subequal in length ( Fig. 22 ). Seta 2a on tergites IX and X shorter than the remaining setae. Dorsal lobe of telson with median pore on a serrated line, ventral lobe with 1+1 sal pores. Female squama genitalis with short, conical acrostyli ( Fig. 35 ). Males unknown.

Body measurements (13 adults, in µm): body length about 1330, head 138–153, pseudoculus 7, distal part of maxillary gland about 25, pronotal seta 1 30–32, pronotal seta 2 15–20, mesonotal P 1 28–29, mesonotal P1 a 8–11, mesonotal P2 36–39, foretarsus 85–89, claw 32–35, empodial appendage about 4.

Chaetal variability. One specimen with a pair of A1 setae (4+4 anterior setae) on mesonotum; two specimens with asymmetrical presence of A1 setae on mesonotum. One specimen with 4 setae and one other specimen with 5 setae (P1a absent asymmetrically) on sternite VIII.

Remarks. The generic position of the taxon originally described as Acerella sharovi has been controversial. Martynova (1977) stated that the species in question belonged in a group with Acerella canadensis (Tuxen, 1955) , which was transferred later into Verrucoentomon ( Imadaté 1981) . However, on the basis of Martynova’s original description, Imadaté (1981) suggested placing this species in the genus Imadateiella . He wrote that "... Acerella sharovi seems characterized by having four pairs of dorsal anterior setae on the thoraces II–III. It is therefore probable that this species takes part in the genus Imadateiella . " Szeptycki (2007) placed this species in Imadateiella without discussion. The differences between Imadateiella and Nipponentomon are not clearcut at present, and Imadateiella needs redefinition and revision (see Discussion). At present I consider this species a member of Imadateiella . Within the genus, the species is most similar to I. shiria ( Imadaté, 1964) in possessing seta P1a and lacking seta P3a on tergites II–VII, having 6 P -setae on sternite III and 6 setae on sternite VIII, in sensillum c being shorter than b and having very short sensilla e and g on the foretarsus. These species differ in the lengths of sensilla a, b and c. Sensillum a is longer in I. sharovi and its apex nearly reaches the base of sensillum t2 and is shorter in I. shiria (apex of sensillum a slightly surpass the sensillum t1 base). Sensilla b and c are shorter in I. sharovi (tip of sensillum b not reaching base of γ3 and tip of c reaching only base of γ2), whereas in I. shiria sensillum b surpasses the base of γ3 and c reaches the base of γ3. Imadateiella sharovi differs from all other species of the genus in the presence of seta Pc on sternite VI.

Nipponentomon khabarovskense Nakamura, 2004 Figs. 37–41

Material examined. Holotype male, 5 paratype males and 8 paratype females, Khekhtsyr Experimental Forestry Enterprise, Korfovsky, Khabarovsk, Russia, 9.IX.2000, coll. M. Hasegawa. These types are preserved in the Zoological Institute of the Russian Academy of Sciences, St. Petersburg, Russia.

Remarks. Examination of the specimens revealed some characters that needed correction or were omitted in the original description: head setae l3, sd4 and sd5 setiform ( Figs. 37, 38 ); hind marginal cephalic setae d7 and sd7 equal in length (about 20 µm); pronotal seta 1 2.5 times longer than seta 2 (57 and 22 µm, respectively); male squama genitalis with 6+6 setae.

In the original description the author reported 6 A -setae on tergite I, but in fact, there are 8 (setae A1, A2, A3 and A5) ( Figs. 39, 40 ). Sternite III has 3 A -setae in the holotype and in one paratype specimen, but the other 12 paratypes have 5 A -setae on sternite III ( Fig. 41 ). This difference likely is intraspecific variability.

Nipponentomon bidentatum Nakamura, 2004 Figs. 42–43

Material examined. Holotype male, paratype female, Khekhtsyr Experimental Forestry Enterprise, Korfovsky, Khabarovsk, Russia, 9.IX.2000, coll. M. Hasegawa. These type specimens are preserved in the Zoological Institute of the Russian Academy of Sciences, St. Petersburg, Russia.

Remarks. The following characteristics are added: head setae l3, sd4 and sd5 sensilliform and blunt apically ( Figs. 42, 43 ); hind margin cephalic setae d7 and sd7 of different lengths (28 and 22 µm, respectively); pronotal seta 1 3.4 times longer than seta 2 (58 and 17 µm, respectively); male squama genitalis with 6+6 setae.

Yamatentomon yamato ( Imadaté &Yosii, 1956) Figs. 44–47

Material examined. 27 females, 19 males, 9 preimagos, 38 maturus juniors, 10 larvae II, soil and litter in deciduous woods, Barabash, Khasansky area, Primorskyi Kray, Russia, 27.IX.2004, coll. R. J. Pomorski; 7 females, 5 males, 2 preimagos, 14 maturus juniors, 9 larvae II, soil in deciduous woods, Chertova Gorka Mt., Kraskino, Khasansky area, Primorskyi Kray, 28. IX. 2004, coll. M. Potapov; 6 females, 2 males, soil and litter of mixed woods, Livadiysky Range, Shkotovsky area, Primorskyi Kray, Russia, 19.IX.2004, coll. J. Pomorski; 2 females, in decaying wood of Pinus koreensis , the same area, 19. IX. 2004, coll. L. Deharveng & A. Bedos; 5 females, 2 males, 8 maturus juniors, soil in mixed woods, Pidan Mt., Livadiysky Range, Shkotovsky area, Primorskyi Kray, Russia, 19. IX. 2004, coll. L. Deharveng & A. Bedos; 2 females and 1 male, soil in cedar woods, Siniy Range, near Spassk, Primorskiy Kraj, Russia, 4.VII.2008, coll. N. Rjabinin; 3 females, 2 males, 1 maturus junior, 1 larva II, soil and litter in mixed forest Ussuriyskiy Reserve, near entrance, Ussurijskiy Kraj, Russia, 5.X.2004, coll. M. Potapov. All of these specimens are preserved in SMNH.

Remarks. The specimens listed above agree well with published description. The following characters are added: foretarsal setae β1 and δ4 long, setiform ( Figs. 44, 45 ); male squama genitalis with 7+7 setae ( Fig. 46 ); sternites VI and VII with a group of adjacent sam pores, placed on the anterior cuticular line, and a pair of spsm pores ( Fig. 47 ).

Callientomon chinensis Yin, 1980 Figs. 48–57

Material examined. Two female specimens, collected in the Primorskyi Kray (detritus without gravel, Sukhodol River, Anisimovka, Livadiysky range, Skotovsky area, coll. J. Pomorski, 21.IX. 2004; soil, forest, Barabash, Khasansky area, coll. L. Deharveng & A. Bedos, 27.IX. 2004). These specimens are deposited in SMNH.

Remarks. The examined specimens differ from the type material in having 6 A -setae on tergite I ( Fig. 48 ), whereas in the type specimens only 4 setae are mentioned ( Yin 1980). Tergites IX and X comprise 12 and 10 setae respectively, not 10 and 8 setae, as was mentioned by Yin (1980). Tergite XI has 6 setae ( Fig. 49 ), rather than 4 setae as in the type specimens. The prosternum in one specimen possesses 4+4 A - and M -setae ( Fig. 50 ). Another specimen has 2+4 A - and M -setae, whereas in the original description only 2+2 A - and M -setae were observed. In the description it was stated that the mesosternum and metasternum each had 5 A -setae, but in the two examined specimens the metasternum has 7 A -setae ( Figs. 51, 52 ). Several characters are corrected or added based on the specimens at hand: tergite I with 10 P -setae ( Fig. 48 ); accessory setae on tergites and sternites short and blunt ( Fig. 53 ), longer only on sternite VII. Foretarsal setae β1 and δ4 short and setiform ( Figs. 54, 55 ). Sternite I with a pair of sal pores ( Fig. 56 ); sternites from V to VII each with a single posteromedial pore spm ( Fig. 57 ).

Despite the apparent differences between the type specimens and the two specimens at hand, the shapes of the foretarsal sensilla and the lengths of the foretarsi are similar. The differences between the type material and these two specimens seem to be only intraspecific variation and so I consider the specimens to be C. chinensis .

Figures

FIGURE 1. Locations of Protura investigated from Siberia and the Russian Far East. 1, Turukhanski area; 2, middle flow of Ob River; 3, middle flow of Enisey River; 4, near Lake Baikal; 5, Altaj mountains; 6, West Sayan mountains; 7, near Yuzno- Sakchalinsk on Sakhalin Island; 8, near Magadan City; 9, near Khabarovsk City; 10, near Spassk City; 11, near Vladivostok City; 12, near Nachodka City.

FIGURES 11 – 17. Imadateiella sharovi (Martynova, 1977). 11) Head. 12) Pseudoculus. 13) Maxillary palpus. 14) Labial palpus. 15) Canal of maxillary gland. 16) Foretarsus, exterior view. 17) Foretarsus, interior view. Arrows show pores. Figs. 12 – 14, paratype a; others, holotype. Scale bar: 20 µm.

FIGURES 18 – 36. Imadateiella sharovi (Martynova, 1977). 18) Thoracic nota. 19) Tergite I. 20) Tergite VI. 21) Tergite VII. 22) Tergites VIII – XII. 23) Prosternum. 24) Mesosternum. 25) Metasternum. 26) Seta A 2 on prosternum. 27) Sternite I. 28) Sternite II. 29) Sternite VI. 30) Sternite VII. 31) Seta P 1 a on tergite VII. 32) Seta P 1 a on sternite VI. 33) Anterolateral part of tergite VII. 34) Comb of tergite VIII. 35) Female squama genitalis. 36) Sternites VIII – XII. Arrows show pores. Figs. 34, 35, paratype b; Figs. 23 – 25, paratype a; others, holotype. Scale bar: 20 µm.

FIGURES 37 – 43. Nipponentomon khabarovskense Nakamura, 2004, holotype. 37) Pseudoculus with setae l 3 and sd 4. 38) Cephalic seta sd 5. 39) Tergite I, frontal part. 40) Tergite I, lateral part. 41) Sternites II and III. Arrows show pores. Nipponentomon bidentatum Nakamura, 2004, holotype. 42) Pseudoculus with setae l 3 and sd 4. 43) Cephalic seta sd 5. Scale bar: 20 µm.

FIGURES 44 – 47. Yamatentomon yamato (Imadaté & Yosii, 1956), specimen from the Russian Far East. 44) Seta β 1 on foretarsus; 45) Seta δ 4 and sensillum c’ on foretarsus; 46) Male squama genitalis, left side; 47) Sternites VI – VII. Arrows show pores. Scale bar: 20 µm.

FIGURES 48 – 57. Callientomon chinensis Yin, 1980, specimen from the Russian Far East. 48) Tergite I, right side. 49) Tergite XI, left side. 50) Prosternum, left side. 51) Mesosternum, left side. 52) Metasternum, left side. 53) Accessory seta on sternite VI. 54) Seta β 1 on foretarsus. 55) Seta δ 4 on foretarsus. 56) Sternite I. 57) Sternite VII. Arrows show pores. Scale bar: 20 µm.

Tables

TABLE 3. Body chaetotaxy of Imadateiella sharovi (Martynova, 1977).

	Formula	Setae	Formula	Setae
Th. I	4	1,2	4+4 6	A1, 2 M1, 2 P1, 2, 3
Th. II	8 16	A2, 3, 4, M P1, 1a, 2, 2a, 3, 3a, 4, 5	5+2 4	Ac, 2, 3, M P1, 3
Th. III	10 16	A1, 2, 3, 4, M P1, 1a, 2, 2a, 3, 3a, 4, 5	7+2 4	Ac, 2, 3, 4, M P1, 3
Abd. I	6 12	A1, 2, 5 P1, 1a, 2, 2a, 3, 4	3 4	Ac, 2 P1, 1a
Abd. II	10 16	A1, 2, 3, 4, 5 P1, 1a, 2, 2a, 3, 4, 4a, 5	3 5	Ac, 2 Pc, 1a, 2
Abd. III	10 16	A1, 2, 3, 4, 5 P1, 1a, 2, 2a, 3, 4, 4a, 5	3 6	Ac, 2 P1, 1a, 2
And. IV–V	10 16	A1, 2, 3, 4, 5 P1, 1a, 2, 2a, 3, 4, 4a, 5	3 8	Ac, 2 P1, 1a, 2, 3
Abd. VI	10 16	A1, 2, 3, 4, 5 P1, 1a, 2, 2a, 3, 4, 4a, 5	3 9	Ac, 2 Pc, 1, 1a, 2, 3
Abd. VII	8 16	A2, 3, 4, 5 P1, 1a, 2, 2a, 3, 4, 4a, 5	3 9	Ac, 2 Pc, 1, 1a, 2, 3
Abd. VIII	6 15	A1, 4, 5 Pc, 1, 1a, 2, 2a, 3, 3a, 5	4 2	1, 2 1a
Abd. IX	12	1, 1a, 2, 2a, 3, 4	4	1, 2
Abd. X	10	1, 2, 2a, 3, 4	4	1, 2
Abd. XI	6	1, 3, 4	6
Abd. XII	9		6