Pterygosomatid mites of a new species group ligare (Acariformes: Pterygosomatidae: Pterygosoma) parasitizing tree iguanas (Squamata: Liolaemidae: Liolaemus) Author Fajfer, Monika Author Acuña, Daniel González text Zootaxa 2013 3693 3 301 319 journal article 10.11646/zootaxa.3693.3.1 f5b63e37-bd23-498a-8adc-5ed83e1daa41 1175-5326 216279 DD72EB94-3FD0-4C37-A5F8-E0AEDE5AF8D7 Pterygosoma formosus sp. nov. ( Figs. 4–6 ) Description. FEMALE ( holotype ). Gnathosoma . Cheliceral base and cheliceral shaft 80 long. Fixed cheliceral digit reduced. Palp setation as in Fig. 6 D, setae dF and dG serrate, 50 and 60 long, respectively. Subcapitular seate n 80 long. Each branch of peritremes with 27–29 chambers. Free lateral part of peritremal branch 40 long. Hypostome 170 long. Idiosoma. Idiosoma 735 long and 1165 wide (650 x 1015 in 1 paratype ). Dorsum ( Figs. 4 A and B). Anterior-mid setal cluster with 107 setae, 30 long ( Fig. 4 B). Lateral to this cluster, about 220–230 setae, 35–45 long present on each side. Anterior to each side of pseudoanal area 16 pairs of setae distinctly plumosed at distal ends located. Postero-lateral parts of idiosoma with short serrated setae (65–115 long) and long setae (200–225 long) serrated only distally. Posterior part of idiosoma with 21–22 pairs of setae slightly expanded apically. Venter ( Figs. 5 A–D) with 13–14 pairs of setae vm , 50–150 long, located laterally to genital area. Peripheral part of body with 32 pairs of postero-lateral setae ( Fig. 5 C) and 4 pairs of peripheral weakly serrated setae ( Fig. 5 D). On each lateral margin between coxal field I and II 1 seta, about 155 long, present. Most part of genital slit situated dorsally. Genital series represented by slightly serrated setae g1 . Pseudoanal setal series represented by 3 pairs. All of them located dorsally, 135–200 long, discernibly serrated at distal part. Legs . Coxal setae 3a slightly serrated. Leg setation: genua (4-4-3-3), femora (5-4-3-2). Setation of tarsi I–III as for genus, tarsi IV with additional setae ft ( Fig. 6 C). FIGURE 4. Pterygosoma formosus sp. nov. , female. A , dorsal view; B , antero-dorsal seta. FIGURE 5. Pterygosoma formosus sp. nov. , female. A , ventral view; B , coxal seta 3b ; C , postero-lateral seta; D , peripheral seta. Type material. Female holotype and 1 female paratype from Liolaemus pictus , CHILE : Isla Mocha, 38º36’32”S , 73º89’87”W , 13 December 2008 , coll. D. González-Acuña. Type deposition. Holotype in the ZISP (ZISP T-Pt-5), paratype in the AMU (AMU-PTE2.1). Etymology. The name formosus refers to the Latin word ” formosus ” which means finely formed. FIGURE 6. Pterygosoma formosus sp. nov. , female; details. A , tarsus I in ventral view; B , tarsus II in lateral view; C , tarsus IV in lateral view; D , gnatosoma in ventral view. Differential diagnosis. P. formosus sp. nov. is similar to P. ligare sp. nov . In females of both species, setation of tarsi I–III and genua I–IV is the same, 16 pairs of setae situated anterior to the pseudoanal area on the dorsum are present. This new species differs from P. l i g a re by the following features: in females of P. formosus , the cheliceral base and the shaft are the same length, all anterior mid-dorsal setae are subequal in the length, there are 220–230 pairs of the mid-dorsal setae, ventro-median setae vm are located laterally to the genital region, only five pairs of the peripheral setae inserted ventrally are present, the pseudoanal series is represented by three pairs of setae ps , all of them are situated dorsally, seta ft on tarsus IV is present, setae v”GI , d”FII and lFIV are absent. In females of P. ligare , the cheliceral base is almost 1.3 times longer than the shaft, the anterior mid-dorsal setae elongate from the anterior to the posterior part of the setal cluster, there are 158–160 pairs of the mid-dorsal setae, ventro-median setae vm are located anterior to the genital region, 13 pairs of the peripheral setae inserted ventrally are present, the pseudoanal series is represented by five pairs of setae ps , three of them are situated ventrally, two pairs are inserted dorsally, seta ft on tarsus IV is absent, setae v”GI , d”FII and lFIV are present.