A new genus and two new species of Tarsonemidae (Acari: Heterostigmata) associated with bark beetles (Coleoptera: Curculionidae: Scolytinae) from Peru Author Khaustov, Alexander A. Author Petrov, Alexander V. 0000-0001-9448-7179 Tyumen State University, 6 Volodarskogo Str., 625003 Tyumen, Russia. & Institute of Forest Science RAS, Sovetskaya st. 21, Uspenskoe, Moscow Region 143030, Russia. https: // orcid. org / 0000 - 0001 - 9448 - 7179; hylesinus @ list. ru Author Kolesnikov, Vasiliy B. 0000-0001-6177-7858 All-Russian Scientific Research Institute for Plant Protection, VNIISS, Voronezh Region, 396030, Russia. https: // orcid. org / 0000 - 0001 - 6177 - 7858; jukoman @ yandex. ru text Zootaxa 2021 2021-04-30 4966 1 41 53 journal article 7151 10.11646/zootaxa.4966.1.4 14130de3-73f2-4b0e-bf78-ad3f951eb67b 1175-5326 4729391 020D9DD0-1FAF-4FEA-B210-DCC271A7733F Unguitarsonemus paradoxus n. sp. ( Figs 1–4 ) Description Female . Length of idiosoma 160 (180), width 95 (100). Gnathosoma ( Fig. 2 ). Length of gnathosomal capsule 30 (31), width 19 (21). Dorsomedian apodeme weakly developed, linear. Gnathosoma with dorsal pair of setae ch 11 (13) slightly shorter than subcapitular setae m 12 (15); both setae slender and smooth. Postpalpal setae ( pp ) slightly shorter than ch , slender and weakly blunttipped. Cheliceral stylets short and thin, nearly half as long as distance between bases of setae ch and distal end of gnathosomal capsule; cheliceral levers small, inconspicuous, poorly sclerotized. Palptibial claw very small, difficult to discern between accessory setigenous structures ( ass ). Idiosomal dorsum ( Fig. 1A ). All dorsal shields with uniform small round puncta. Prodorsum with very small median apodeme. Trichobothria capitate, ellipsoidal, finely spiculate and rounded apically.Anterior part of prodorsal shieldlet, lateral and posterior parts of prodorsal shield with delicate striae. Tergites C and D with finely serrate posterior margins. Posterior parts of tergites C, D, and EF with delicate longitudinal striae. All dorsal idiosomal setae smooth; setae v 1 , sc 2 , c 1 and c 2 pointed, other dorsal setae weakly blunt-tipped. Posterior margin of tergite H weakly concave. Lengths of dorsal setae: v 1 32 (36), sc 2 39 (44), c 1 21 (20), c 2 34 (35), d 19 (21), e 26 (31), f 39 (40), h 15 (19). Distances between setae: v 1 – v 1 21 (23), v 2 – v 2 39 (43), sc 2 – sc 2 47 (52), c 1 – c 1 50 (53), c 2 – c 2 92 (98), c 1 – c 2 28 (31), d–d 40 (42), e–e 68 (71), e–f 21 (22), f–f 26 (30), h–h 33 (36). FIGURE 2. Unguitarsonemus paradoxus n. gen., n. sp. , female: A—gnathosoma, dorsal aspect, B—gnathosoma, ventral aspect. FIGURE 3. Unguitarsonemus paradoxus n. gen., n. sp. , female: A—left leg I, dorsal aspect, B—tarsal part of tibiotarsus I, ventral aspect, C—left leg II, dorsal aspect, D—tarsus II, ventral aspect. Idiosomal venter ( Fig. 1B ). All ventral plates with uniform, very small puncta.All ventral setae smooth, pointed. Pits 1 b and 2 b large, elongate. Posterior margin of aggenital plate evenly rounded. Setae 1 a located just anteriad apodemes 1; setae 2 a located on apodemes 2. Tegula broadly rounded, length 14 (17), basal width 16 (18). Lengths of ventral setae: 1 a 11 (12), 2 a 14 (16), 3 a 11 (12), 3 b 15 (18), ps 14 (16). Legs ( Figs 3 , 4 ). Lengths of legs: I 52 (59), II 50 (60), III 59 (63), IV 35 (39). Leg I ( Figs 3A, B ): solenidion ω lanceolate, φ 1 and φ 2 capitate; seta k 3 (3) rod-shaped, subequal to solenidion φ 2 . Lengths of solenidia: ω 6 (6), φ 1 6 (6), φ 2 3 (3). Setae l’ and l” of genu weakly barbed, other leg setae smooth; setae d , l′ of femur, l′ , l” , v′ , v” of genu, ( p ), ( tc ) and ( u ) of tarsus blunt-tipped; other leg setae pointed. Tarsal part of tibiotarsus ventrally with tubelike sclerotized subcuticular structure ( Fig. 3B ). Leg II ( Fig. 3C ): solenidion ω 6 (6) lanceolate. Setae d and l′ of femur weakly blunt-tipped, other leg setae pointed; all leg setae smooth. Leg III ( Fig. 4A ): all leg setae pointed and smooth. Leg IV (Fig, 4B): all leg setae pointed and smooth. Seta tc″ very long. Lengths of setae: v’Fe 9 (10), v’Ge 15 (16), v’Ti 32 (36), tc” 100 (105). Type material. Female holotype , slide ZISP T-Tar-001, PERU : Junín Prov ., left bank of Perené River , 5 km NE from Puerto Ocopa , Canan Eden village, 1100 m , S11°04’23.9’’ W74°16’40.6’’ , 10.03.2009 , between coxae I and II on beetles Phloeotribus pilula ( Erichson , 1847 ) , A. Petrov leg. Paratype : 1 female , same data . Type deposition . The holotype and one paratype are deposited in the collection of the Zoological Institute of RAS, Saint Petersburg , Russia . Etymology . The specific epithet of the new species is derived from Latin paradoxus meaning paradoxical and refers to remarkable shape of modified seta pl” on tarsus II.