Loxosceles puortoi, Martins, Rosana, Knysak, Irene & Bertani, Rogério, 2002

Martins, Rosana, Knysak, Irene & Bertani, Rogério, 2002, A new species of Loxosceles of the laeta group from Brazil (Araneae: Sicariidae), Zootaxa 94, pp. 1-6 : 2-5

Loxosceles puortoi sp. nov.

Figs. 1–7 .

Holotype male ( IBSP 34728) and paratype female ( IBSP 34729) from Tatu Cave, Palmas, Tocantins, Brazil (09°59'10''S, 48°19'20''W), 16.vi.2001, R. Martins, I. Knysak & G. Puorto coll.

Etymology. The specific name is a patronym for the Brazilian herpetologist Giuseppe Puorto for his efforts in helping to collect the type specimens.

Diagnosis. Males can be readily recognized from other species by the very narrow palpal femur and tibia: the palpal femur is about 11 times longer than wide and the palpal tibia about 5 times longer than wide ( Figs. 3, 4 ). Females can be distinguished from all other species except L. coquimbo Gertsch, 1967 , L. virgo Gertsch & Ennik, 1983 , L. lawrencei Caporiacco, 1955 and L. rufipes (Lucas, 1834) by the presence of four spermathecae ( Fig. 5 ). It is distinguished from L. coquimbo by not having the tibia and tarsus of the palp incrassate and by leg II being longer than leg IV; from L. lawrencei and L. rufipes by not having the two spermathecae of each side largely fused in the basal portion; and, from L. virgo by having the two spermathecae of each side with similar width.

Description. Male (Holotype). Total length 5.2. Carapace 2.4 long, 2.3 wide. Eye sizes: ALE: 0.13, PME: 0.15, PLE: 0.13. Clypeus equal in width to two and one­half diameters of PME. Distance between PME and PLE equal to 0.33 diameters of PME. PME separated from ALE by 1.3 diameters of former. Leg formula II, IV, I, III. Leg I: femur 4.3 / patella 0.7 / tibia 4.9 / metatarsus 4.8 / tarsus 1.2 / total 15.9 / II: 4.9 / 0.9 / 6.2 / 6.3 / 1.2 / 19.5 / III: 4.0 / 0.8 / 3.8 / 4.7 / 0.9 / 14.2 / IV: 4.3 / 0.8 / 4.4 / 5.7 / 1.1 / 16.3. Leg I 6.6 times as long as carapace; femur I 1.8 times as long as carapace. Metatarsus I without a sinuous curve in the middle portion. Palpal femur 11.6 times longer than wide, palpal tibia 5.7 times longer than wide; cymbium slightly elongated. Bulb suboval in side view, shorter than cymbium. Embolus curved, twice as long as bulb width, without carina. Carapace covered by many short, curved setae.

Carapace with pars cephalica and border dark brown, contrasting with olive brown pars thoracica. Legs olive brown.

Female (Paratype). Total length 8.0. Carapace 3.0 long, 2.6 wide. Eye sizes: ALE: 0.15, PME: 0.15, PLE: 0.13. Clypeus equal in width to two and one­half diameters of PME. Distance between PME and PLE equal to 0.37 diameters of PME. PME separated from ALE by 1.4 diameters of former. Leg formula: II, IV, I, III. Leg I: femur 3.9 / patella 0.9 / tibia 3.8 / metatarsus 3.7 / tarsus 1.1 / total 13.4 / II: 4.2 / 0.9 / 4.2 / 4.3 / 1.1 / 14.7 / III: 3.6 / 0.9 / 3.1 / 3.6 / 0.9 / 12.1 / IV: 3.9 / 0.9 / 3.7 / 4.4 / 1.0 / 13.9. Leg I 4.5 times as long as carapace. Femur I 1.3 times as long as carapace. Palpal tarsus not incrassate. Four tubular spermathecae, the internal ones having a curvature in the distal portion ( Fig. 5 ). Colour pattern as in male, except the palpal tibia and tarsus, which are reddish brown.

Additional material examined: Brazil, Tocantins: Palmas, Tatu Cave (09°59'10''S, 48°19'20''W), 16.vi.2001, R. Martins, I. Knysak & G. Puorto coll., 10 females (IBSP 34730); same locality and collectors, 11–19.viii.2001, 1 male (IBSP 34731); Miracema do Tocantins (09°45'23''S, 48°22'58''W), same collectors, 17–25.iv.2002, 1 female (IBSP 34732). Besides the preserved material, 22 living specimens are being kept at the Laboratório de Artrópodes of the Instituto Butantan.

Distribution. Brazil: Palmas and Miracema do Tocantins, State of Tocantins.

Discussion. The new species can be included in the laeta group of Gertsch (1967) based on details of genitalia. These are: bulb of palpus suboval, embolus longer than diameter of bulb, absence of wing or carina in the embolus, and tibia of palpus at least twice as long as cymbium in male. Female has four tubular spermathecae closely positioned, free, and without a cluster of small globular lobes at apex ( Fig. 5 ).

Of the four groups of species of the South American Loxosceles fauna proposed by Gertsch (1967), only the laeta group did not have native species in Brazil. The only species occurring in the country was L. laeta , which seems to have been introduced either from Peru or Chile ( Gertsch & Ennik 1983). The group is particularly speciose in the Andean region of South America, mainly Peru, from where 17 of the 24 species were described ( Gertsch 1967).

Natural History. Specimens of Loxosceles puortoi were collected in the mountain range of Lajeado at an altitude of 240 m. The predominant vegetation is the savannah-like ‘cerrado’. This is intermixed with gallery forest with trees 20–30 m in height. The soil is a

sandy clay with a dense litter layer. This area is underlain by a sedimentary rock formation, in which there is a small cave (5 x 1.7 x 2.5 m). Adults and immatures of L. puortoi were found under rocks and inside rock crevices, both inside and outside the cave. The females build a loose web roughly 100 mm in diameter. Immatures, probably in the 4th or 5th instars, were found both in the litter and under small rocks. Remains of ants ( Hymenoptera : Formicidae ) were found in great quantities attached to the webs.

Figures

FIGURES 1 – 5. Loxosceles puortoi. (1 – 2) Carapace. 1, paratype female; 2, holotype male. (3 – 4) right male palp (holotype). 3, retrolateral view; 4, prolateral view. 5, female paratype, spermathecae. Scale bars = 1 mm.