Two new species of Eustigmaeus Berlese (Acari: Trombidiformes: Stigmaeidae) from Brazil, with a key to the American species Author Paktinat-Saeij, Saeid Author Bagheri, Mohammad Author De Castro, Tatiane M. M. G. Author De Moraes, Gilberto J. text Zootaxa 2016 4066 5 571 580 journal article 51165 10.11646/zootaxa.4066.5.5 eddb988d-489f-4cfa-b3fc-14004f0e474b 1175-5326 263977 E778225E-7276-4553-A932-80EC0C46C5F6 Key to females of Eustigmaeus Berlese, 1910 of America 1 Dorsal idiosomal setae acicular, clavate or flattened; smooth or sparsely barbed.................................... 2 - Dorsal idiosomal setae short, densely barbed or bushy....................................................... 30 2 With one pair of aggenital setae; dorsal body setae arcuate or flattened........................................... 3 - With two or three pairs of aggenital setae; dorsal idiosomal setae acicular or clavate............................... 10 3 Femur II with four setae; genua III with two setae........................................... E. smithi (Chaudhri) - Femur II with five setae; genua III with one seta............................................................. 4 4 Coxisternal shield separated..................................................... E. modiola (Summers & Price) - Coxisternal shield fused................................................................................ 5 5 Dimples on dorsal shields with vacuoles................................................................... 6 - At least most of the dimples on dorsal shields without vacuoles................................................. 7 6 Tarsus II with 8(+1ω) setae; dorsal setae slender, sharply pointed, with barbs......................... E. segnis (Koch) - Tarsus II with 9(+1ω) setae; dorsal setae with broad membranous vanes...................... E. microsegnis (Chaudhri) 7 Dorsal idiosomal setae with barbs........................................................................ 8 - Dorsal idiosomal setae almost smooth..................................................................... 9 8 Tarsus II with 8(+1ω) setae; distance e1–e1 subequal to f1–f1................................. E. arcuata (Chaudhri) - Tarsus II with 9(+1ω) setae; distance e1–e1 double f1–f1.................. E. floridensis Maake, Ueckermann & Childers 9 Tarsus II with 8(+1ω) setae; coxisternal shield smooth...................................... E. chilensis (Chaudhri) - Tarsus II with 9(+1ω) setae; coxisternal shield reticulated...................................... E. oliveirai sp. nov. 10 With two pairs of aggenital setae........................................................................ 11 - With three pairs of aggenital setae....................................................................... 16 11 Setae 4a absent..................................................................... E. parviseta (Chaudhri) - Setae 4a present..................................................................................... 12 12 Humeral callosities absent............................................................................. 13 - Humeral callosities present............................................................................ 14 13 Dorsal shields ornamented with minute dimples; sci short (10 Μm).......................... E. bryonemus Flechtmann - Dorsal shields ornamented with polygonal dimples; sci normal (30–36 Μm)......................... E. arctica (Wood) 14 Tarsus IV with 6(+1ω) setae; trochanter III with one seta.......................... E. kauaiensis Swift, Gerson & Goff - Tarsus IV with 7(+1ω) setae; trochanter III with two setae.................................................... 15 15 Aggenital area reticulated; dorsal setae clavate or acicular, with spinules and hyaline sheaths; length of setae ve distinctly greater than distance ve–sci.................................................... E. schusteri (Summers & Price) - Aggenital area smooth; dorsal setae clavate or with acutely pointed apex, minute barbed and hyaline sheaths; length of setae ve not greater than distance ve–sci............................................................ E. rotunda (Wood) 16 Eyes absent......................................................................................... 17 - Eyes present........................................................................................ 19 17 Femur IV with three setae........................................................... E. parasitica (Chaudhri) - Femur IV with two setae.............................................................................. 18 18 Dorsal idiosomal setae long, barbulate with blunt tips; coxisternal shields reticulate................ E. gorgasi (Chaudhri) - Dorsal idiosomal setae relatively short, plumose; coxisternal shields smooth..................... E. gamma (Chaudhri) 19 Tarsus IV with 7 setae................................................................................ 20 - Tarsus IV with 7(+1ω) setae............................................................................ 24 20 Setae 4a absent...................................................................... E. capella (Chaudhri) - Setae 4a present..................................................................................... 21 21 With two humeral callosities............................................................ E. lacuna (Summers) - Without humeral callosity............................................................................. 22 22 Trochanter III with one seta; setae h1 and h2 simple, without hyaline sheaths; with extra shield on idiosoma.............................................................................................. E. piracicabensis sp. nov. - Trochanter III with two setae; setae h1 and h2 clavate, with hyaline sheaths; not extra shield on idiosoma.............. 23 23 Dorsal shields strongly reticulate..................................................... E. reticulatellus (Habeeb) - Dorsal shields uniformly dimpled, dimples circular to oval shape.................... E. clavata (Canestrini & Fanzago) 24 Humeral callosities absent............................................................... E. ovata (Chaudhri) - Humeral callosities present............................................................................ 25 25 Dorsal idiosomal setae without hyaline sheaths; aggenital plate smooth or weakly reticulated........................ 26 - Dorsal idiosomal setae with hyaline sheaths; aggenital plate distinctly reticulated................................. 28 26 Ornamentation of dorsal shields faint, dimples shallow, no evident reticulum; approximate ratio of lengths ve : vi = 1.5, ve : c2 = 4.0; c2 very short 19 Μm.................................................................. E. ottavii (Berlese) - Ornamentation of dorsal shields reticulate or polygonal; approximate ratio of lengths ve : vi = 1.0, ve : c2 = 1.3–1.6; c2 short 26– 31Μm.............................................................................................. 27 27 Dorsal shields uniformly ornamented with pits surrounded with polygonal walls; dorsal setae clavate and apically barbed; dis- tance d1–d1 about 1.5 times as long as distance e1–e1......................................... E. frigida (Habeeb) - Dorsal shield with pores in marginal area, minute punctations and faint reticulations in central area; dorsal setae tapered with pointed tips, not barbed; distance d1–d1 about the same as distance e1–e1......................... E. najeeba (Habeeb) 28 With two pairs of subequal humeral callosities; dorsal shields distinctly reticulated................ E. acidophila (Wood) - Anterior callosity distinctly larger than posterior callosity; dorsal shields faintly reticulate........................... 29 29 Dorsal shields ornamented with small, roughly oval, shallow dimples; dimples vacuolated mostly around the perimeters, with 0–3 central vacuoles; dorsal setae are thickest subapically and clavate, minutely barbed and with hyaline sheaths, h1 and h2 barbed, ve : c2 = 1.5; spine k on genu I approximately 1/3 as long as dorsal setae on genu I; humeral callosities punctuated finely................................................................................. E. gersoni (Wood) - Dorsal shields minutely punctate, with dimples and vacuoles the bases of the dimples are unvacuolated; dorsal setae clavate to rod-like and with hyaline sheaths; ve : c2 = 2; spine k on genu I approximately 1/2 as long as dorsal setae on genu I, humeral callosities with pores.................................................................. E. rhodamela (Koch) 30 Femur II with four setae.............................................................. E. anauniensis (Ewing) - Femur II with five setae............................................................................... 31 31 Eyes absent.................................................................... E. lirella (Summers & Price) - Eyes present........................................................................................ 32 32 Coxisternal shields smooth; setae e1 about 17 Μm................................... E. craticola (Summers & Price) - Coxisternal shields reticulated; setae e1 at least 32 Μm....................................................... 33 33 Dorsal idiosomal setae as long as or longer than the distances between their successive bases; longest spinules less than twice as long as diameter of setal axis......................................................... E. collegiensis (Wood) - Dorsal idiosomal setae shorter than the distances between their successive bases; longest spinules more than twice as long as diameter of setal axis................................................................................. 34 34 Dimples on dorsal shields of uniform shape (polygonal) and size; c1–c1 approximately 68 Μm........ E. myrtae (Chaudhri) - Dimples on dorsal shields varying in shape and size; c1–c1 approximately 54 Μm.................. E. plumifer (Halbert)