Amazoniaseius, Demite, Peterson R., Cruz, Wilton P. & Moraes, Gilberto J., 2017

Demite, Peterson R., Cruz, Wilton P. & Moraes, Gilberto J., 2017, Amazoniaseius imparisetosus n. sp., n. g.: an unusual new phytoseiid mite (Acari: Phytoseiidae) from the Amazon forest, Zootaxa 4236 (2), pp. 302-310 : 303-304

Amazoniaseius new genus Demite, Cruz & McMurtry

Diagnosis. Protonymphs, deutonymphs and adult females with dorsal idiosomal setae long, distinctly barbed in adults (but slightly barbed in nymphal stages), dorsal shield narrowed, J5 relatively long (over twice as long as distance J5–J5); fixed cheliceral digit with few teeth. Deutonymphs and adult females with an unpaired seta immediately behind j6 (x) and another immediately behind J2 (X); z3, z6, s6, J4 present; macrosetae present only on genu, tibia and tarsus of leg IV; Z1, S5, JV3, JV4, ZV1–ZV3 absent; anal shield with a pair of small pores on anterolateral margins.

Adult female. Dorsum of idiosoma with 21 pairs of setae (j1, j3–j6, J2, J4, J5, z2–z6, Z4, Z5, s4, s6, S2, S4, r3, R1) and two unpaired setae (x and X). Setae J5 and S2 displaced respectively anteriad and posteriad of their usual position. Dorsal shield strongly narrowed. Ventral shields distinct. Sternal shield with three pairs of setae and two pairs of lyrifissures. Seta st 4 set on metasternal plate. Posterior margin of genital shield broadly rounded. Anal shield ovoid, with a pair of pores on anterolateral margins. With three pairs of opisthogastric setae (JV1, JV2 and JV5; all on unsclerotised cuticle) in addition to circumanal setae. Peritreme extending to level of j3. Fixed cheliceral digit with 2–3 teeth in addition to apical tooth; movable digit edentate. Macrosetae present only on genu, tibia and tarsus IV.

Adult male. Unknown.

Deutonymph. Dorsal idiosomal setae as in adult female. Sternogenital shield with five pairs of setae (st1–st5). Opisthogastric region with two pairs of setae (JV1 and JV2) in addition to circumanals. Peritreme extending to level between z2 and z3. Leg macrosetae as in adult female.

Protonymph. Dorsum of idiosoma with 17 pairs of setae, distinguished from adult female and deutonymph by the absence of j4, z3 and z6; seta J5 also displaced anteriad of usual position. Ventral shields indistinguishable; with st1–st3, JV1, JV2, JV5 and circumanal setae. Peritreme extending to the level of s6. Leg macrosetae as in deutonymph and adult female.

Etymology. The name of this genus is a combination of Amazonia referring to Amazonia rainforest, plus seius (a Roman surname commonly used to compose names of mesostigmatic mites).

Remarks. This taxon is placed in Typhlodrominae by having setae z3, s6, S2 and S4. The presence of J4 is reported for the first time in Typhlodrominae , whereas the absence of all ZV setae is reported for the first time in Phytoseiidae . Within this subfamily, this genus is placed in Paraseiulini ( Wainstein, 1976) by the presence of z6 and S4, but it differs from the other genera in this tribe by the presence of the unpaired setae and J4, by the absence of S5, JV4 and ZV, by the narrow dorsal shield and the presence of anal shield.

A long seta J5 is not a common characteristic in this family; J5 as long as Z5 has been reported for Macrocaudus Moraes, McMurtry & Mineiro (Amblyseiinae) , but even in that case, those setae are shorter than the distance between their bases ( Moraes et al., 2003). A broadly rounded posterior margin of the genital shield has been reported for Amblyseiella Muma and Phytoseiulus Evans (Amblyseiinae) , but apparently for none of the Typhlodrominae genera. Among the phytoseiids, the presence of extra unpaired dorsal setae of the idiosoma has not been reported. However, a single seta anteriad of J2 has been reported in some specimens of Australiseiulus angophorae (Schicha) (Typhlodrominae) , whereas in other specimens two setae or none have been found ( Schicha, 1981); other species of the same genus do not have that seta, interpreted by Beard (1999) as J1. Other phytoseiids reported to have seta J1 belong to the Amblyseiinae , namely Chileseius Gonzalez & Schuster , Diaphoroseius Chant & McMurtry , Evansoseius Sheals and Rubuseius Ragusa , as well as a few species of Typhodromalus Muma and Typhlodromips De Leon ( Chant & McMurtry, 2007) . Australiseiulus poplar Beard has a J seta interpreted by Beard (1999) as J4. In comparison with some specimens of Arrenoseius palustris (Chant) and with Macrocaudus multisetatus Moraes, McMurtry & Mineiro , the only phytoseiid species ( Amblyseiinae ) reported to have J3 ( Moraes et al., 2003; Chant & McMurtry, 2007), and with species of the closely related family Blattisociidae ( Lindquist & Evans, 1965) , it seems that this seta could instead be J3. Seta J4 has been reported in several phytoseiid genera (all Amblyseiinae ), namely Evansoseius , Pararrenoseius Chant & McMurtry , Rubuseius , as well as in Chileseius camposi Gonzalez & Schuster , M. multisetatus , Typhloseiella perforata (Wainstein) and some specimens of A. palustris ( Chant & McMurtry, 2007) .

Extra setae are quite commonly found in other mesostigmatid mites, including species of Ascidae , Blattisociidae and Melicharidae (Moraes et al., 2016) and Laelapidae ( Evans & Till, 1966) . Most often, extra setae are found in only some of the species of each genus. Thus, other species of this new genus may lack the setae here referred to as x and X.