Amazoniaseius imparisetosus Demite, Cruz & McMurtry

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 : 304-305

Amazoniaseius imparisetosus Demite, Cruz & McMurtry

Female (n = 15). Figures 1–5 .

Dorsum. 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 r3 and R1 on unsclerotised cuticle. Dorsal shield ornamented with nodular structures, one pair of pores and four pairs of lyrifissures distinguishable, 290 293 (275–310) long and 102 105 (100–112) wide. Setal length: j 1 25 27 (25–28), j3 35 37 (34–40), j4 44 42 (40–45), j5 58 60 (56–63), j6 75 77 (70–81), J2 72 75 (72–77), J4 48 50 (45–57), J5 57 57 (51–69), z 2 31 30 (25–33), z3 40 41 (40–43), z4 66 65 (61–70), z5 36 37 (35–39), z6 57 60 (55–65), Z4 48 50 (46–53), Z5 70 73 (70–80), s4 80 81 (76–89), s6 87 93 (87–100), S2 70 71 (68–77), S4 68 68 (65–74), r3 45 49 (44–54), R1 57 57 (52–60), x 60 62 (55–67), X 50 54 (48–61). Setae barbed and pointed.

Venter. Ventral shields distinct. Sternal shield lightly reticulate, with three pairs of setae and two pairs of lyrifissures; distance between st1–st3 60 62 (54–65), st2–st2 61 61 (59–64). Seta st4 on metasternal plate. Genital shield smooth, with posterior margin broadly rounded; distance between st5–st5 67 66 (62–72). Anal shield ovoid, lightly reticulate and with a pair of pores on anterolateral margins; 67 64 (58–67) long, 50 51 (44–55) wide at anus level. With three pairs of opisthogastric setae (JV1, JV2 and JV5; all on unsclerotised cuticle) in addition to circumanal setae; JV5 47 50 (47–53). Ventral setae smooth. Metapodal plates indistinguishable. Peritreme extending to level of j3.

Spermatheca. Calyx cup- to bell-shaped, 10 11 (10-13) long; atrium relatively small, but distinct.

Chelicera. Fixed cheliceral digit 29 29 (27–30), with 2–3 distal teeth in addition to apical tooth and pilus dentilus; movable digit 25 26 (24–27) long, edentate.

Legs. Macrosetae of the following lengths: Sge IV 60 59 (57–62), Sti IV 41 43 (40–46), St IV 110 109 (104– 115), all pointed; other legs without macrosetae. Chaetotatic formulae: genu II – 2 2/1 2/0 1; genu III – 1 2/1 2/0 1.

Deutonymph (n = 2). Figures 6–7 .

Dorsum. Chaetotaxy as in adult female. Dorsal shield lightly reticulate, pores and lyrifissures not distinguishable, 244–247 long and 110–121 wide. Setal length: j1 21, j3 35–38, j4 41–44, j5 63–65, j6 89–91, J2 66–75, J4 38–39, J5 40–52, z2 28, z3 35–38, z4 70–78, z5 34–38, z6 52–57, Z4 37–38, Z5 52–54, s4 84 –88, s6 86 – 90, S2 70 – 79, S4 50 –53, r3 39–40, R1 41–42, x 58 –63, X 35 –40. Setae slightly barbed and pointed.

Venter. Shields weakly sclerotised. Sternogenital shield with five pairs of setae (st1–st5) and only a pair of distinguishable lyrifissures. Anal shield indistinguishable. Opisthogastric region with two pairs of setae (JV1 and JV2), in addition to circumanal setae; JV5 35-36, visible dorsally in mounted specimen. Peritreme extending to level between z2 and z3.

Chelicera. Not clearly visible.

Legs. Macrosetae of the following length: Sge IV 50, Sti IV 58 –60, St IV 114–115, all pointed; other legs without macrosetae.

Protonymph (n= 2). Figures 8–9 .

Dorsum. Dorsal shield barely distinguishable; pores and lyrifissures not distinguishable; 190–200 long and 100–108 wide. Setal length: j 1 19–22, j 3 30–31, j4 38–40, j5 69–70, j6 90–94, J2 52–54, J 5 21–25, z 2 28–32, z4 70–74, z 5 28–32, Z 4 26–28, Z5 36–38, s4 79–86, s6 44–45, S4 52, r 3 23–24, R 1 13–15. Setae slightly barbed and pointed, except R1 apparently smooth and pointed.

Venter. Ventral shields indistinguishable. Venter with st1–st3, JV1, JV2, JV5 and circumanal setae. Peritreme short, extending to level of s6.

Chelicera. Not clearly visible.

Leg. Macrosetae of the following length: Sge IV 62 –67, Sti IV 65 –70, St IV 105–108, all pointed; other legs without macrosetae.

Type material (15 females, 2 deutonymphs and 2 protonymphs)

Holotype female, 8 paratype females, 2 paratype deutonymphs and 2 paratype protonymphs: Rio Preto da Eva (02°26’04” S; 59°33’46” W), Amazonas state, Brazil, collected by W.P. Cruz from Elaeis oleifera (Kunth) Cortés (Arecaceae) on January 22, 2013; deposited at Departamento de Entomologia e Acarologia , Universidade de São Paulo, Escola Superior de Agricultura ‘ Luiz de Queiroz ” ( ESALQ / USP), Piracicaba , São Paulo state, Brazil. One paratype female collected on May 14, 2013 and one paratype female collected on October 30, 2012; other collection data and depository as for holotype ; one paratype female, collected from Astrocaryum aculeatum G.F.W Meyer (Arecaceae) on March 26, 2013; other collection data and depository as for holotype; three paratype females, same collection data as holotype; all deposited at Departamento de Zoologia e Botânica, UNESP - Universidade Estadual Paulista , São José do Rio Preto, São Paulo state, Brazil.

Etymology. The name imparisetosus refers to the presence of unpaired setae in the dorsal shield.

Remarks. The identification of some dorsal shield setae in this study is provisional, because of their unique position within the phytoseiids. One of the uncertainties refers to the identity of the seta called x in this paper. Is that a podonotal or opisthonotal seta? That seta, observed in the examined deutonymphs and adult females, could actually correspond to J1. Supportive of this interpretation is the absence of this seta in some specimens and the occurrence of two x setae in one of the specimens collected. The very anteriad position of x in relation to what would be expected for the normal position of J1 argues against that interpretation. Also against this interpretation is the fact that in Ascidae sensu Lindquist & Evans (1963) , a group taxonomically close to the phytoseiids (see Lindquist et al., 2009 and Famah-Sourassou et al., 2015), J1 normally first appears in the protonymphal stage, whereas in the taxon here described it appeared only in the deutonymphal stage. Thus, we could conclude that the most anterior unpaired seta is podonotal, occupying the same location as the unpaired podonotal setae found in Spadiseius calyptrogynae Lindquist & Moraza (Melicharidae) ( Lindquist & Moraza, 2008). The fact that this seta is not found in Spadiseius spathiphyllae Lindquist & Moraza suggests its instability in different species of that genus (and perhaps in the genus here described). Alternatively, if that seta is really J1, it would be necessary to argue that the strong lateral compression of the dorsal shield caused disturbance to the normal chaetotactic pattern, leading to the appearance of J 1 in the deutonymphal rather than in the protonymphal stage. The tendency towards evolutionary loss of J1 could also explain its instability in the deutonymph and adult.

It could be argued that the seta interpreted as S 2 in this work is actually S3, because of the position. A point against that interpretation is that S3 has never been reported for phytoseiids. Its first appearance in the deutonymphal stage makes its identification more difficult because in Ascidae sensu Lindquist & Evans (1965) S2 first appear in the protonymphal stage, whereas S3 first appear in the larval stage. The actual absence of S5 is supported by the fact that the usual position of this seta is posterolaterad of the pore located anterolaterally of Z5 (idm5 of Athias-Henriot, 1969).

Wide variation is observed among Amazoniaseius imparisetosus n. sp. specimens in relation to the absence of some opisthonotal setae (all of which inserted behind J2): X in five specimens, one J 5 in two specimens, X and one J 5 in one specimen, one S 4 in two specimens, one Z 4 in three specimens, and one Z4 and one S 4 in one specimen. Intra-specific variations as presence or absence of setae, place of insertion of setae, lengths of setae etc., have been reported for other species (e.g. Kolodochka, 1995; Demite et al., 2008; Toyoshima & Amano, 2013; Tixier et al., 2016).

The idiosomal setal pattern of the new taxon here described has never been reported in Phytoseiidae . On the ventral surface of the idiosoma, the absence of all ZV setae has not been previously reported. Thus, our interpretation of the dorsal idiosomal setae in the new taxa here described leads us to propose a new setal pattern for the phytoseiids: 13A+x:8F+X/JV-3,4:ZV-1–3.

Figures

FIGURES 1 – 5. Amazoniaseius imparisetosus n. sp., n. g.. Female: 1. Dorsal idiosoma, 2. Ventral idiosoma, 3. Chelicera, 4. Spermatheca, 5. Genu, tíbia and basitarsus of leg IV.

FIGURES 6 – 9. Amazoniaseius imparisetosus n. sp., n. g.. Deutonymph: 6. Dorsal idiosoma, 7. Ventral idiosoma. Protonymph: 8. Dorsal idiosoma, 9. Ventral idiosoma.