Pseudobryobia nikitensis (Livshits & Mitrofanov, 1969)

Barbar, Ziad, 2018, New mite records (Acari: Mesostigmata Trombidiformes) from soil and vegetation of some Syrian citrus agrosystems, Acarologia 58 (4), pp. 919-927 : 923-925

Pseudobryobia nikitensis (?) (Livshitz and Mitrofanov, 1969)

Specimens collected —. Borj-Islam and Attabiyyat: Nine females on S. spinosum , 25 May, 2016 and 15 March, 2018.

This species was also previously recorded on S. spinosum in Ukraine ( Livshits and Mitrofanov, 1969) and Italy ( Vacante, 1983) and on Silene dioica (L.) (unknown locality, Migeon and Dorkeld, 2006 -2017). The Syrian specimens are very close to those described by Livshits and Mitrofanov (1969) and similar to those reported in the redescription of Vacante

(1983), except for a few small morphological differences namely: (1) in Syrian specimens,

setae v1–v2 elongated, slender and serrate ( Figure 1a ); setae sc1–sc2 and c1–c3 subspatulate

( Figure 1b, c ); remaining dorsal body setae palmate serrate and almost rounded distally ( Figure 1d ), but dorsohysterosomal setae are subspatulate, lanceolate and more or less acute in the description of Livshits and Mitrofanov (1969), and setae d, e, and f are subspatulate in the redescription of Vacante (1983) (according to Figure presented); (2) femur II with 9 (10) setae in Syrian specimens oppose to 8 in the description of Livshits and Mitrofanov (1969); genu

III with 6 (7) setae in Syrian specimens oppose to 5 setae in the description of Livshits and Mitrofanov (1969).

Furthermore, the assignment of this species to the genus Pseudobryobia may be uncertain. Indeed, in the diagnoses proposed by the authors who worked on this genus (e.g. Meyer, 1987; Baker and Tuttle, 1994; Smiley and Baker, 1995), in addition to the absence of prodorsal lobes, it is mentioned that members of the fourth pair of dorsocentral setae f (1 setae) are located in normal dorsal position (not marginal). However, this condition is neither met by the specimens of P. nikitensis described by Livshits and Mitrofanov (1969), Vacante (1983) nor by those reported in this study.

Figures

Figure 1 Variations in the shape of dorsal body setae in the Syrian specimens ofPseudobryobia nikitensis: a – prodorsal setae; b –sc1 seta; c – c1 seta; d –d1 seta.