Neoseiulella arutunjani (Kuznetsov), 1994

Kanouh, M., Kreiter, S., Douin, M. & Tixier, M. - S., 2012, Revision Of The Genus Neoseiulella Muma (Acari: Phytoseiidae). Re-Description Of Species, Synonymy Assessment, Biogeography, Plant Supports And Key To Adult Females, Acarologia 52 (3), pp. 259-348 : 283-285

Neoseiulella arutunjani (Kuznetsov)

( Figure 9 )

Seiulus (Typhloctonus) arutunjani Kuznetsov 1984: 54-57 . Neoseiulella arutunjani (Kuznetsov) Chant and McMurtry 1994: 248 ; Moraes et al. 2004: 292; Chant and McMurtry 2007: 147.

Adult female ( Figure 9a – d )

Dorsal shield ( Figure 9a ) — Dorsal shield heavily reticulated throughout: length 313; width 155 (at level of s4), 160 (at level of Z1). Four pairs of large solenostomes: gd2, gd5, gd6, and gd9. No poroid visible. Sub-lateral seta r3 on the dorsal shield. The other sub-lateral seta R1 on the lateral margin. Dorsal shield bearing 20 pairs of setae, all dorsal and sub-lateral setae smooth, except Z5 slightly serrated: j1 13; j3 19; j4 12; j5 12; j6 19; J2 20; J5 10; z2 12; z3 19; z4 20; z5 13; Z1 20; Z4 24; Z5 38; s4 22; s6 20; S2 22; S4 20; S5 16; sub-lateral setae r3 13 and R1 24. Peritreme extending anteriorly to the level between z2-j3.

Ventral shields ( Figure 9b ) — Sternal shield 63 long and 51 wide (at level of ST2), smooth with two pairs of setae (ST1 and ST2) and two pairs of poroids. The third and fourth pairs of sternal setae (ST3, ST4) on separate platelets. A pair of small poroids accompanying ST4. Genital shield 105 long and 49 wide (at level of ST5), smooth. Four elongate platelets or genital sigilla between genital and ventrianal shields. One pair of poroids close to the genital shield (ST 5) and 3 pairs of poroids around the genital shield. Ventrianal shield subquadrateshape, 110 long and 78 wide (at level of ZV2), distinctly reticulated throughout, with four pairs of preanal setae (JV1, JV2, JV3 and ZV2), with a pair of circular solenostomes gv3 posteromediad to JV3. Four pairs of caudoventral setae (ZV1, ZV3, JV4 and JV5) on the integument surrounding the ventrianal shield. NB: one seta of the JV4 pair is present (reported absent on the original description) supporting Kolodochka (2009). JV5 13 long, smooth. Primary metapodal plate or inguinal sigillum 35 long and 4 wide.

Spermatheca ( Figure 9c ) — Cervix short, 4 long, shallowly cup-shaped.

Chelicera ( Figure 9d ) — Seven teeth and a pilus dentilis on the fixed digit. Movable digit 29 long, bidentate.

Legs — Measurements of legs: leg I 248; leg II 213; leg III 213; leg IV 283. Seven setae (2-2/0, 2/0- 1) on the genu II. No macroseta on legs.

Material examined — The female holotype deposited in the collection of Nikita State Botanic Garden, Yalta, Crimea, Ukraine. This material was examined in the ASU, Institute of Zoology, Academy of Sciences, Kiev, Ukraine.

Adult male

The male of this species is unknown.

Previous reports — N. arutunjani is only known from Ukraine, on Artemisia sp. ( Asteraceae ).

Remarks — It is noteworthy that in the original description, two females mounted on one slide were mentioned. Kolodochka (2009) showed that only one female actually belonged to this species. The other female was Paraseiulus incognitus Wainstein and Arutunjan. Our examination of these two females supports Kolodochka’s observations.

The present examination of the type materials of these three latter species could emphasize the following conclusions:

Neoseiulella tuberculata does not differ from N. sexapori in setal and body measurements. Even if the shape of the spermatheca of these two species is slightly different (cup-shaped cervix in N. sexapori and a disc-shaped [shallowly cup-shaped] cervix in N. tuberculata ), these two types of shapes are very close and such differences could be simply due to specimen mounting artefacts. The pair of solenostomes gd5 is observed on the four examined specimens of N. sexapori , and only on one of the three type specimens of N. tuberculata . At last, we observe other differences not mentioned by Chant and Yoshida-Shaul (1989): all dorsal setae are arising from tubercles in N. sexapori but not in N. tuberculata ; the peritreme is shorter (at level between z2-j3) for N. sexapori than for N. tuberculata (at level of j1 or between j1-j3); the number of teeth on the fixed digit is different (three for N. sexapori , five for N. tuberculata ); the ventrianal shield is heavily reticulated in N. sexapori , and lightly in N. tuberculata . As some authors have already shown the importance of such morphological characters for species differentiation (Chant and McMurtry 1994; Tixier et al. 2006a, b; Chant and McMurtry 2007; Okassa et al. 2009), we conclude that N. tuberculata and N. sexapori seem to be separate specific entities. These results agree with the conclusions of Karg and Edland (1987), but not with Chant and Yoshida-Shaul (1989).

Small differences in setal and body measurements are observed between N. tuberculata and N. arutunjani . According to intraspecific variations already observed within the family Phytoseiidae for continued characters, these differences seem to be too tiny for separating N. tuberculata from N. arutunjani . However, other differences are observed: the peritreme is shorter in N. arutunjani (reaching between z2-j3) than in N. tuberculata (reaching j1 or between j1-j3); the ventrianal shield is heavily reticulated on N. arutunjani , and lightly on N. tuberculata ; fixed digit of chelicera bear seven teeth on N. arutunjani , and five on N. tuberculata ; sub-lateral seta r3 is inserted on the dorsal shield on N. arutunjani and on lateral margin on N. tuberculata . However, as the position of sub-lateral seta (R1) was demontrasted to be a non reliable diagnostic character to differentiate between N. aceri and N. squamiger ( Kanouh et al. 2010) , the position of r3 could be also assumed to be a non reliable diagnostic character as well. Though, the other morphological differences between N. tuberculata and N. arutunjani seem sufficiently discriminant to conclude that these two species are not synonyms. These results do not agree with the conclusion of Kolodochka (2009).

Small differences in setal and body measurements are observed between N. arutunjani and N. sexapori . However, all dorsal setae are arising from tubercles on N. sexapori , but not on N. arutunjani ; the number of teeth on the fixed digit is different (three on N. sexapori , seven on N. arutunjani ); spermatheca has a cup-shaped cervix in N. sexapori , but a discshaped (shallowly cup-shaped) cervix in N. arutunjani . These morphological differences between N. sexapori and N. arutunjani seem also sufficiently discriminant to conclude that these two species are not synonyms.

It seems thus that N. tuberculata , N. arutunjani and N. sexapori present sufficiently different characters to support their specific validity. These conclusions did not agree with Chant and Yoshida-Shaul (1989) and Kolodochka (2009).

Figures

FIGURE 9: Neoseiulella arutunjani (Kuznetsov). Female (holotype): a – dorsal shield; b – ventral shields; c – spermatheca; d – chelicera.