Bomis larvata L. Koch, 1874

Szymkowiak, Paweł & Królikowska, Sylwia, 2017, Redescription of Bomis larvata L. Koch, 1874 with the description of a new Australian species, Zootaxa 4323 (4), pp. 451-468 : 453-455

Bomis larvata L. Koch, 1874

Figs 1–28 .

Bomis larvata L. Koch, 1874: 528 , pl. 40, figs 4, 4d (female). L. Koch 1876: 798, pl. 69, fig. 4 (male). Simon 1895: 1005, figs 1068–1069.

Etymology. No etymological explanation was provided in the original description by L. Koch. “ Larva ” means mask, ghost in Latin. Maybe “ larvata ” refers to the immature form of an adult; in the context of the species it may refer to the tiny size of the species which resembles juvenile spiders.

Type material: Syntypes: AUSTRALIA: Queensland: 1 female, Rockhampton ( NMW 1884 I 402, examined) ; 3 females, Port Mackay (1 female detached: body, palpi, chelicerae; slide 3421a) ( ZMB 3421 , not examined) ; 1 female, Port Mackay ( ZMH 9933 , examined) .

Other material examined. AUSTRALIA: New South Wales: 2 males, Sydney , L. Koch det. (personal communication Dr. Jürgen Gruber) ( NMW 1882 II 124) . Queensland: 1 male, Priestdale, Burbank, Buhot Creek , 50 m, riparian forest, sweeping net, 51198, [27°35.5'S, 153°10.3'E], 30 April 2003, E. Volschen leg. ( QM S 62820 ) ; 3 males, 4 females, Priestdale, Burbank, Buhot Creek , 50 m, riparian forest, sweeping net, 51685, [27°35.5’S 153°10.3’E], 6 November 2003, S. Wright leg. ( QM S 67498 ) ; 1 female, Priestdale, Burbank, Buhot Creek , 50 m, riparian forest, sweeping net, 51855, [27°35.5’S, 153°10.3’E], 18 February 2004, QM party leg. ( QM S 67499 ) ; 10 females, North Stradbroke Island Enterprise, Blackbutt , 90 m, sweeping net, 50934, [27°33’S, 153°28’E], 9 January 2002, C. J. Burwell leg. ( QM S 55680) ; 10 females, North Stradbroke Island Enterprise, Blackbutt , 80 m, sweeping net, 50936, [27°35’S, 153°28’E], 9 January 2002, C. J. Burwell leg. ( QM S 56152) ; 1 female, North Stradbroke Island Enterprise, Mallee , 120 m, sweeping net, 50937, [27°34’S, 153°26’E], 11 January 2002, C. J. Burwell leg. ( QM S 55681 ) ; 8 females, North Stradbroke Island Enterprise, Scribbly Gum , 70 m, sweeping net, 50942, [27°36’S, 153°27’E], 10 January 2002, C. J. Burwell leg. ( QM S 55679) ; 3 females, Port Mackay , Keyserling coll. ( NHML 1890.7.1.3468-70) ; 2 males, 1 female, Rockhampton ( NHML 1915.3.5.3344–46) . Western Australia: 1 female, Dirk Hartog Island, Brown Station, Stat. 67, Hartmeyer and Michelsen, Hamburg S.W. Austral., Exp. 1905, 14 September 1905 ( ZMB 16614, not studied) .

Diagnosis. Ventral margin of clypeus shaped like a curly bracket ( Figs 3 , 8 , 14–15 ). Venter of opisthosoma with one oval apodeme in the middle ( Fig. 17 ). Epigyne nearly as wide as long with two protruding conical protuberances situated close to its lateral margins, epigynal orifices directed exteriorly on protuberances ( Figs 5 , 11–12 , 19 ). Male palp with subelliptical or nearly spherical tegulum and straight embolus half the length of the tegulum ( Figs 21 , 27 ); cymbial notch on retrolateral side of palp ( Fig. 28 ).

Redescription. Female: Body length: 1.75–2.66 (mean=2.24, SD±0.18, n=37): prosoma length: 0.58–1.38 (mean=0.99, SD±0.11, n=40), prosoma width: 0.82–1.4 (mean=1.02, SD±0.09, n=40), prosoma height: 0.45–0.98 (mean=0.67, SD±0.12, n=40), prosoma length/width ratio: mean 0.97 (n=40), opisthosoma length: 1.18–2.4 (mean=1.45, SD±0.22, n=39), opisthosoma width: 0.95–2.88 (mean=1.75, SD±0.27, n=39), opisthosoma height: 0.8–2.48 (mean=1.24, SD±0.29, n=38), opisthosoma length/width ratio: mean 0.83 (n=39). Prosoma highly convex, greatest height in the middle ( Fig. 4 ), greatest width at about two third of height ( Figs 3 , 8 ), dorsal part (excluding posterior declivity and including clypeus and the area of eyes) covered by numerous, minute tubercles and small cavities ( Figs 3–4 , 8 , 14 ). Clypeus length about 0.4, runs steeply toward chelicerae ( Fig. 4 ), anterior margin with acute point in the middle of chelicerae ( Figs 3 , 8 , 14–15 ), ratio of clypeus length to AME-AME distance 1.9. Eyes. All lenses small (0.035 –0.049), PMEs being the smallest, ALEs equal in size to PLEs, ALEs and PLEs on small tubercles, PMEs oval in shape, slightly elevated, orientated rearward, AMEs without welldefined eye chambers, ALE, PLE and PME closer to each other than to AME ( Figs 3 , 8 ), MOA of trapezium shape, broad in comparison to the area of all the eyes; AME-AME 0.24, AME-ALE 0.14, ALE-PLE 0.15, PLE-PME 0.17, PME-PME 0.38, AME-PME 0.25, PLE-PLE 0.54, MOA length 0.31, MOA width anterior 0.32, MOA width posterior 0.46, x/y ratio 0.67 ( Fig. 7 ), diameter of lenses: ALE=PLE>AME>PME ( Fig. 8 ), size of eye tubercles: ALE ≈ PLEŻPME>AME. Chelicerae small (length approx. 0.32) with small fangs and wide promarginal area with numerous short, massive, peg-like setae ( Figs 10 , 15 ). Labium triangular and acute with individual setae, length 0.22, width 0.14; maxillae with dense scopula on proximal end, length 0.33; width of labium + maxillae 0.48. Sternum heart-shaped ( Fig. 9 ), rounded with broad, undivided posterior end (nearly half the width of the sternum) ( Fig. 16 ), widest at one third of its length, width ratio of its widest part to the width of posterior end 2.31, covered with plumose setae, most numerous on the margins; whole area raised with considerably convex margins and a plain central part, integument reticulate with alveolate and elongated small cavities ( Fig. 16 ), most rugous on margins; length 0.62, width 0.49. Legs with a pair of dentate claws and reticulated integument comprised of wrinkles and small cavities; all tarsi with ventral scopulae, patellae with slit-like sensillae organs ( Fig. 25 ), similar to those in Porropis flavifrons L. Koch, 1876 (Szymkowiak unpublished); leg formula: II-I-IV-III.

Length of leg segments in females of Bomis larvata :

Opisthosoma wider than long, shape plano-concave in most specimens ( Fig. 6 ) or globular (female, NHML 1915.3.5.3344–46)—possibly the side-effect of long preservation ( Fig. 2 ); dorsum having an apodeme pattern of 1- 2-2 ( Fig. 7 ), with distance between anterior apodeme and the intermediate pair of apodemes less than twice the distance between intermediate and posterior pair of apodemes ( Fig. 18 ), surface of integument highly wrinkled ( Fig. 18 ), lateral and posterior part with significant folds ( Fig. 7 ), integument covered by tiny spiniform setae, spinnerets recessed in a rounded cavity, circled by numerous setae. Epigyne small ( Figs 5 , 11 ), nearly rounded, width (0.3) slightly greater than length (0.25) ( Figs 5 , 12 , 19 ); two longitudinal outlines of insemination ducts and spermathecae not adhering to each other ( Figs 5 , 13 ), insemination ducts short, running without deviation towards spermathecae ( Fig. 12 ); vulval structures with two disjointed sac-like spermathecae ( Figs 12–13 ), oval in shape. The prosoma is dark brown laterally with light brown stripes in the central part ( Figs 1, 6 ); the eyes (ALEs, PLEs, PMEs) are dark, except the AMEs which are light-colored; chelicerae, palps and legs light brown, opisthosoma marbled lighter proximally and darker distally, with blackish paths around the posterior pair of apodemes; a white, transverse stripe extends below the intermediate pair of dorsal apodemes ( Figs 6–7 ); the margins of the opisthosoma have elongated white-grey stripes which run parallel towards the spinnerets; opisthosoma ventrally plain, epigyne pale.

Male: Body length: 1.38–2.28 (mean 1.83, SD±0.4, n=6), prosoma length: 0.7–1.25 (mean 1, SD±0.18, n=8), prosoma width: 0.72–1.19 (mean 0.99, SD±0.18, n=8), prosoma height: 0.38–0.76 (mean 0.61, SD±0.14, n=6), prosoma length/width ratio: mean 1 (n=8), opisthosoma length: 0.8–1.51 (mean 1.14, SD±0.22, n=8), opisthosoma width: 0.92–1.62 (mean 1.34, SD±0.26, n=8), opisthosoma height: 0.68–1.08 (mean 0.89, SD±0.17, n=6), opisthosoma length/width ratio: mean 0.86 (n=8). The prosoma’s length is equal to its width and it is covered by numerous tubercles ( Figs 20 , 23 ). Clypeus long (0.2–0.39), ratio of clypeus length/AME-AME 2 (1.91–2.22, n=2), clypeus margin shape as in female ( Fig. 24 ). Dimensions of eyes and eye tubercles nearly equal to their female counterparts (PMEs smallest), x/y ratio 0.75, diameter of lenses ALE>PLE>>AME>PME, size of eye tubercles ALE=PLE>PME>AME. The legs (tibiae in particular) are covered by different types of setae: baciliform, spiniform, and setiform with different types of setae surfaces (mostly squamous and spiculate) and various types of setae ornamentation (mostly ciliate) ( Fig. 26 ), legs densely covered by trichobothria (long, fine, curved hairs) ( Fig. 26 ), leg surface rugose ( Fig. 26 ), patellae with distinct slit-like sensillae ( Fig. 25 ), leg formula II-I-IV ≈ III. Other parts of the body and appendages are as described for the female above. The cymbium has a cymbial notch in distal position on retrolateral side ( Fig. 28 ) and the whole surface covered by plumose setae and individual smooth, baciliform setae on top.

Distribution. The Australian species is known from Queensland, New South Wales and Western Australia.

Habitat preferences. The species was often found in litter or in herbal vegetation in woodland (riparian forest).

Figures

FIGURES 1–6. Bomis larvata, female. 1–2 habitus (1 dorsal, 2 lateral); 3–4 prosoma (3 frontal, 4 lateral); 5 epigyne, ventral; 6 different patterns of dorsum. Scale bars: (1, 2) = 1 mm; (3, 4) = 0.1 mm; (5) = 0.05 mm; (6) = 0.5 mm.

FIGURES 7–13. Bomis larvata, female. 7 habitus, dorsal; 8 prosoma, frontal; 9 sternum; 10 chelicerae with fangs and peg-like setae; 11 epigyne, ventral; 12 epigyne, ventro-lateral; 13 vulva, dorsal. Scale bars: (7, 8) = 1 mm; (9–13) = 0.1 mm.

FIGURES 14–19. Bomis larvata, female, SEM photos. 14 prosoma, frontal; 15 clypeus and chelicerae; 16 sternum, posterior; 17 opisthosoma, ventral, anterior; 18 opisthosoma, dorsal; 19 epigyne, ventral. Scale bars: (14, 15, 17, 18) = 1 mm; (16, 19) = 0.02 mm.

FIGURES 20–22. Bomis larvata, male. 20 habitus, dorsal; 21–22 left pedipalp (21 ventral, 22 retrolateral). Scale bars: (20) = 1 mm; (21, 22) = 0.1 mm.

FIGURES 23–28. Bomis larvata, male, SEM photos. 23 prosoma and fore legs, frontal; 24 clypeus and chelicerae; 25 slit sensilla on patella of leg IV; 26 setae on metatarsus of leg I; 27 right pedipalp, ventral; 28 left pedipalp, retrolateral. Scale bars: (23) = 0.02 mm; (24, 25, 27, 28) = 0.03 mm; (26) = 0.02 mm.