Baculentulus kulsarinae Likhitrakarn & Nakamura

Likhitrakarn, Natdanai, Nakamura, Osami, Wiroonrat, Wassana & Suttiprapan, Piyawan, 2016, Baculentulus kulsarinae sp. nov. from Thailand (Protura: Acerentomata, Acerentomidae), Zootaxa 4092 (3), pp. 431-435 : 431-434

Baculentulus kulsarinae Likhitrakarn & Nakamura sp. nov.

( Figs 1 & 2 , Table 1 )

Materials examined. Holotype: female (mounted) (CUMZ-1401), Thailand, Chiang Mai Province, Doi Inthanon, tropical montane forest mainly dominated by M. euonymoides , 18°34' N, 98°28' E, 1,650 m a.s.l., 30.I.2007, leg. N. Likhitrakarn. Paratypes: 1 male (CUMZ-1405) and 3 females (mounted) (CUMZ- 1402-1404), same data as holotype.

Etymology. To honour Dr. Jiraporn Kulsarin, Professor at the Department of Entomology and Plant Pathology of Chiang Mai University, Chiang Mai, who participated in taught and encourage the first author throughout this work.

Diagnosis. Baculentulus kulsarinae sp. nov. is characterized by foretarsal sensillum b longer than c, lacking b’, possessing two pairs of anterior setae, A4 and A5, on abdominal tergite VII, 14 setae on IX, 12 setae on XI, presence of P1a on abdominal tergites II–VII, and absence of P3a on VIII. It is most similar to B. matsuokai (Imadaté) which was also found from Thailand. The species differs in the shape of sensilla d and v on maxillary palp and lengths of foretarsal sensilla e, f and g.

Description. Body length 790–893 µm. Head oval, length 84–88 µm, width 71–77 µm. Rostrum not protruded; additional setae d6 absent; l3, sd4 and sd5 sensilliform ( Fig. 1 A). Maxillary palpus with two sensilla on penultimate segment, dorsal sensillum d slightly thinner and longer than ventral sensillum v ( Fig. 1 C). Labial palpus with three setae and one sensillum ( Fig. 1 B). Pseudoculus almost circular ( Fig. 1 D), length 6.0–6.5 µm, width 6.4–7.0 µm, PR = 13.3– 14.7. Canal of maxillary gland with smooth calyx, posterior part short, CF = 3.1–3.9 ( Fig. 1 H).

Foretarsus ( Fig. 1 J & K) length 64–71 µm, claw without inner flap, length 21–22 µm, TR = 3.0–3.2; empodium length 3.9–5.0 µm, EU = 0.18–0.23, setae s length 24–27 µm. Dorsal sensillum t1 baculiform, BS = 0.42–0.45; t2 normal and long; t3 small and spatulate. Interior sensillum a long, its apex nearly reaching base of γ3; b long, reaching base of γ4; c and d long, both apices almost reaching base of f; e and f long, its apex nearly reaching γ5; g short, its apex reaching base to γ5. Interior sensillum a' broad and long, distally contracted, its apex surpassing base of γ3; b' absent; c' long, its apex surpassing tarsus. Pores between a and α3, and between g and t3. Middle tarsal length 29–32 µm, claw length 13– 15 µm; hind tarsal length 33–36 µm, claw length 13–16 µm.

Chaetotaxy as shown in Table 1 and Fig. 2 A–C. Thoracic tergites II–III with dorsal P1a and P2a on minute, clubshaped, 2 µm in length. Abdominal tergite I–VI with three pairs of anterior setae, A1, 2 and 5; VII with two pairs, A4 and 5; IX with 14 setae; X with 12 setae. P3 on abdominal tergites II–VI anterior to other principal setae; those on VII same level to other principal setae ( Fig. 2 A). On tergites II–VIII, accessory setae P1a present and P3a absent. Abdominal sternite I with one pair of P1; VIII without posterior setae; IX–X with 4 setae. Accessory setae on abdominal segments I– VII all short and sensilliform, less than 6 µm in length.Integumental pores distinct. Thoracic tergite II with pores anterolateral pores (al) and sublateral pores (sl); thoracic tergite III with sl only ( Fig. 2 C). Abdominal tergites I–VIII with posterosubmedial pores (psm); V–VII with al; II–VII with posterosublateral pores (psl); II–VII with anteromembranal pore (amb) at anterior part of pleura, VI with sternal posterosubmedial pores (spsm) ( Fig. 2 B). Abdominal sternites V–VI with a pair of pore anterolateral to P1; VII with a pair of spsm at middle between P1 and P1a ( Fig. 2 B). Telson with a dorsal central pore at the anterior border.

Abdominal appendage I with 4 setae and terminal vesicle ( Fig.1 E); II–III with two setae, subapical seta (28–30 µm) longer than median apical seta (10–13 µm) ( Fig. 1 F &G). On abdomen VIII, striate band reduced, striae not distinct ( Fig. 2 A); comb oblique and consisting of about nine irregular teeth ( Fig. 2 D). Male squama genitals with 4+4 dorsal setae and 1+1 ventral setae ( Fig. 1 I). Female squama genitals with curved and pointed acrostyli ( Fig. 2 E).

Remarks. The genus Baculentulus consists of 38 species worldwide and is distributed in southwestern and eastern Asia, North and South America, eastern Africa and Australia (Bai & Bu, 2013; Bu et al., 2014; Nakamura & Likhitrakarn, 2009; Shrubovych, 2010; Szeptycki, 2007; Wu & Yin, 2008). Baculentulus kulsarinae is similar to B. breviunguis (Condé) from Madagascar, Réunion, India, Thailand and China (Tuxen, 1964; Imadaté,1965; Yin, 1999), B. umesaoi Imadaté from Thailand and India (Imadaté,1965; Prabhoo, 1975), B. matsuokai Imadaté and B. lanna Imadaté from Thailand (Imadaté,1965) and B. seychellensis Tuxen from Seychelles (Tuxen, 1978) in lacking foretarsal sensillum b', having foretarsal sensillum b longer than c, abdominal tergite VII with two pairs of anterior setae, A4 and 5, and presence of P1a on abdominal tergites II-VII. Among them, the present new species differs from the species in longer foretarsal sensilla a and e (in other species a passing to base of γ2 and e evidently not reaching the base of claw). The new species is closer to B. matsuokai and B. lanna , which are different from other species in having 14 and 12 setae on abdominal tergites IX and X, respectively (12 and 10 setae in other species). This new species and B. matsuokai are different from B. lanna in possessing three pairs of anterior setae, A1, 3 and 5 (A1 absent in B. lanna ) on tergite VIII. This species is distinguished from B. matsuokai in the shape of sensilla d and v on maxillary palp (both sensilla thick and same length in B. matsuokai ), foretarsal sensillum e longer than f (shorter than f in B. matsuokai ) and length of foretarsal sensilla f and g (surpassing tarsus in B. matsuokai ). Moreover this species is different from B. lanna in the relative lengths of foretarsal sensilla c and d (not reaching the base of e in B. lanna ), e (not surpassing the base of g in B. lanna ), g (surpassing tarsus in B. lanna ) and c' (not reaching the base of δ 6 in B. lanna ).

Figures

FIGURE 1. Baculentulus kulsarinae sp. nov., female holotype (B, C), male paratype (A, D, H, I), female paratype (E – G, J, K). A: dorsal view of head. B: labial palp. C: maxillary palpus. D: pseudoculus. E, F, G: abdominal appendages I, II, III, respectively. H: canal of maxillary gland. I: male squama genitalis. J, K: foretarsus, exterior and interior view, respectively. Arrows indicate pores. Scale bar: 10 µm.

FIGURE 2. Baculentulus kulsarinae sp. nov., female holotype (A – C, E), male paratype (D). A, B: abdominal segments VI – VIII, dorsal and venter view, respectively. C: thoracic tergites II – III and abdominal tergite I, left half. D: comb on abdominal tergite VIII. E: female squama genitalis. Arrows indicate pores. Scale bar: 20 µm (A – C), 10 µm (D, E).

Tables

TABLE 1. Adult chaetotaxy of Baculentulus kulsarinae sp. nov.

	Dorsal		Ventral
	Formula	Setae	Formula	Setae
Thorax I	4	1, 2	414	A1, 2, M1, 2
				P1, 2, 3
II–III	412	A2, 4, M		Ac, 2, 3, 4, M
		P1, 1a, 2, 2a, 3, 3a, 4, 5		P1, 2
Abdomen I		A1, 2, 5		Ac, 2
		P1, 1a, 2, 2a, 3, 4		P1
II–III		A1, 2, 5		Ac, 2
		P1, 1a, 2, 2a, 3, 4, 4a, 5		Pc, 2, 3
IV–VI		A1, 2, 5		Ac, 2
		P1, 1a, 2, 2a, 3, 4, 4a, 5		P1, 1a, 2, 3
VII		A4, 5		Ac, 2
		P1, 1a, 2, 2a, 3, 4, 4a, 5		P1, 1a, 2, 3
VIII		A1, 3, 5, Mc, 2, 3, 5		A1, 2
		P2, 3, 4, 5
IX	14	1, 1a, 2, 2a, 3, 4, 5	4	1, 2
X	12	1, 2, 2a, 3, 4, 5	4	1, 2
XI	XII	6	9	1, 2, 3	Ac, 1, 2, 3, 4	6	6	1, 2, 3 XII 9 Ac, 1, 2, 3, 4 6 1, 2, 3	1, 2, 3
XII	9	Ac, 1, 2, 3, 4	6	1, 2, 3