Anisentomon hainanense, Xiong, Yan, Bu, Yun & Yin, Wen Ying, 2008

Xiong, Yan, Bu, Yun & Yin, Wen Ying, 2008, A new species of Anisentomon from Hainan, Southern China (Protura: Eosentomidae), Zootaxa 1727, pp. 39-43 : 39-42

Anisentomon hainanense , new species

( Figs. 1–15 )

Diagnosis. This new species is characterized by the presence of four anterior setae on urosternites IV–VII and six setae on urosternites IX–X, also by one pair of curved spines on urotergite X in the position of setae A1.

Description. Adult. Female body length 625–735 µm (n=2). Male unknown.

Head. Oval, length 68 µm, width 58–60 µm (n=2). Cephalic setae short. Subposterior seta 1. 2 x length of posterior seta. Anterior additional and posterior additional setae also present ( Fig. 1 ). Pseudoculus circular, width 8–9 µm. PR=8–9. Clypeal apodeme indistinct. Rostral setae simple, subequal to subrostral setae ( Fig. 2 ). Labral setae absent. Mandibles with three distinct apical teeth. Digits of galea well-developed, median and inner equal, shorter and thicker than outer digit ( Fig. 3 ).

Thorax. Chaetotaxy given in Table 1 . Tracheal camerae length 5 µm. Spiracle diameter 2 µm ( Fig. 4 ). On mesonotum and metanotum, P1a setiform, situated posterior to the row of P1 and P2, P2 relatively long, length ratio of P1: P1a: P2 on mesonotum as 1.8: 1.0: 2.3. Sternites of thorax with no pores.

Foretarsal length ( Figs. 9–10 ) 45–48 µm, claw length 6.0–7.5 µm, TR =6–8; empodium subequal to claw, EU=0.8–1.0; dorsal sensillum t-1 short, spindle-like, slightly closer to α 3 than to α 3', BS=0.9–1.0; t-2 short, clavate; t-3 short, linear. Exterior sensilla a and c short, subequal to each other; b long, reaching β 7; d short and broad; e absent, g spatulate; f-1 short, distinctly clavate; f-2 short, linear. Interior sensillum a' robust and long; b'-1 long, nearly reaching base of b'-2 which is short and claviform; c' reaching level of α 6 base. Middle tarsal length 15–18 µm, claw length 6.0–7.5 µm. Hind tarsal length 20–23 µm, claw length 7.5 µm. Empodia of middle tarsi length 4 µm and empodia of hind tarsi length 5 µm ( Figs. 5–6 ). Basal seta (seta D2) of hind tarsus normal shape ( Fig. 7 ).

Abdomen. Chaetotaxy given in Table 1 . Abdominal tergite I with 2 pairs of anterior setae (A1, A2), with 6 pairs of posterior setae (P1, P1a, P2, P3, P3a, P4a), P3a and P4a specialized as short sensillum-like. Urotergites II–VII with 4 pairs of anterior setae (A1, A2, A4, A5). Urotergites II–III with 6 pairs of posterior setae (P1, P1a, P2, P3, P3a, P4), IV–VII with 8 pairs. Urosternites IV–VII with 2 pairs of anterior setae (A1, A2) and 5 pairs of posterior setae. Setae P1a on urotergites I–VI long, longer than P1 ( Fig. 13 ); on urotergite VII P1a situated posteriorly to the level of P1–P2, shorter ( Fig. 14 ); P2a on urotergites II–VI shorter than P1a ( Fig. 13 ).

P1a' on urotergite VIII in the medial position between P1a and P2. Urotergites I–VI without pores, VII and IX with 1 pair of posterior pores. Urosternites I–VII without pores, VIII–X with one medial pore each. Urotergite X with one pair of large, curved spines, length 15–18 µm; base of each spine surrounded by a ringed filmy sclerite with a coracoid-like appendage pointed to the inner side ( Fig. 8 , Fig. 18 ). Segment XII without dorsal pores, with 2 anterior ventromedial pores. On female squama genitalis, caput processus simple and straight, corpus processus rather narrow, filum processus acute and long ( Fig. 15 ).

Holotype. Female (intact, mounted in Hoyer solution) (No: PHN 031010), from semideciduous seasonal rainforest on Mt. Jianfeng, 18 o 43' N, 108o 54' E, elev. 220 m, between Ledong and Dongfang counties, Hainan Province, China, 6 October 2003, collected by Dr. Yan Xiong, deposited in the Shanghai Entomological Museum (SEM).

Paratype. 1 female (intact, mounted by Hoyer solution) (No: PHN 031011), same data as for holotype.

Etymology. The species is named after Hainan Province where the type specimens were collected.

Remarks. The presence of a pair of large spines on urotergites X or XI is a unique character in genus Anisentomon . The position, structure, and shape of the spines differ among the species. In A. chinensis Yin, 1977 and A. quadrisetum Zhang et Yin, 1981 the spines are sinuate and located on urotergite X in the position of setae A1; each spine base is surrounded by a ringed filmy sclerite with a coracoid-like appendage pointed to the inner side ( Fig. 16 , Fig. 17 ). In A. heterochaitum Yin, 1977 , the spines are in the A2- seta position on urotergite X, and are seta-like, straight and without a basal appendage ( Fig. 19 ). In A. magnispinosum ( Yin, 1965) , the spines occur on urotergite XI and in the position of seta A1; they are straight and lack a basal appendage ( Fig. 20 ).The shape and position of spines in A. hainanense are similar to A. chinensis and A. quadrisetum , which indicate these three species may be closely related. They can be distinguished from the chaetotaxy of urosternites IV–X and empodium of middle and hind tarsi (see the key).

Figures

FIGURES 1 – 15. Anisentomon hainanense, new species. 1, head; 2, rostral and subrostral setae; 3, mandible and galea; 4, spiracle; 5, claw of middle tarsus; 6, claw of hind tarsus; 7, hind tarsus; 8, spines on urotergite X; 9, foretarsus, exterior view; 10, foretarsus, interior view; 11, urotergites VII – XII; 12, urosternites VII – XII; 13, hind part of urotergite VI; 14, hind part of urotergite VII; 15, female squama genitalis.

FIGURES 16 – 20. Photomicrographs of spines in Anisentomon spp. 16, A. chinensis (female, 12 th, Oct. 1985, Sichuan); 17, A. quadrisetum (Syntype, female, 4 th, Dec. 1985, Guangxi); 18, A. hainanense, new species (Holotype, PHN 031011); 19, A. heterochaitum (female, Nov. 1987, Zhejiang); 20, A. magnispinosum (female, 28 th, Jul. 1985, Sichuan).

Tables

TABLE 1. Chaetotaxy of Anisentomon hainanense, new species

Thorax I	Dorsal Formula 4	Setal composition 1,2	Ventral Formula Setal composition – A1,2,3,M ------------ P1,2,3
II	------	A2,4,M P1,1a,2,2a,3,3a,4,5	– A1,2,3,M ------------ P1,2,3
III	------	A2,4,M P1,1a,2,2a,3,3a,4,5,5a	– A1,2,3,M1,2 ------------ P1,2,2a,3
Abdomen I	------	A1,2 P1,1a,2,3,3a,4a	A1,2 --- P1,2
II– III	------	A1,2,4,5 P1,1a,2,2a,3,4	A1,2,3 --- P1,2
IV–VII	------	A1,2,4,5 P1,1a,2,2a,3,4,4a,5	A1,2 ------ P1,2,2a,2a',3
VIII	---	M2,3,4 Pc,1a, 1a',2,2a	A --- Pc,1,1a,2
IX X XI XII	8 2+6 8 9	1,2,3,4 1,2,3,4 1,2,3,4	6 1,1a,2 6 1,1a,2 8 1,2,3,4 12