New records of the genus Bryobia (Acari: Tetranychidae) from Syria with description of a new species

Three species of Tetranychidae belonging to the genus Bryobia were collected from Latakia governorate, Syria in 2019: Bryobia (Allobia) syriensis n. sp. collected from Salvia verbenaca L., is described; Bryobia (Allobia) nikitensis and Bryobia (Bryobia) gigas collected from S. verbenaca and from soil litter, respectively, are reported. New observations of Bryobia specimens previously reported from the same governorate during 2014-2016 revealed that specimens of Bryobia (Bryobia) watersi were misidentified as Bryobia (Bryobia) graminum and Bryobia (Bryobia) kissophila. Among them, we found two aberrant females bearing three propodosomal lobes. By analogy, we discussed the cases of the trilobed species, Bryobia bakeri and Bryobia aegyptiacus, and concluded that they could be teratological forms of quadrilobed Bryobia species rather than species with a particular pattern of propodosomal lobes.


Introduction
Among the spider mite family, the genus Bryobia is the fourth largest genus in terms of species (Migeon and Dorkeld, 2019) and since the revision of the genus Pseudobryobia by Arabuli et al. (2019), it contains 143 taxa.
The aims of the current paper are to present the results of some field samplings of Bryobia species undertaken in Latakia governorate in 2019 and to re-examine all specimens of this genus collected in the same governorate over the period 2014-2016 and reported by Barbar (2014Barbar ( , 2018. The description of a new species of Bryobia is provided. A new record, new host plants and the cases of misidentifications are reported. Finally, the observation of unusual Bryobia specimens' prodorsal lobes lead us to discuss the identity of Bryobia bakeri (Zaher, Gomaa and El-Enany, 1982) and Bryobia aegyptiacus (Zaher, Gomaa and El-Enany, 1982).

Field sampling
Samplings of tetranychid fauna were conducted in Latakia governorate in April and June, 2019. Mites were collected from soil litter and from leaves of common weed species within a small forest (about six hectares, 57 m above the sea level) of Pinus halepensis Mill. located at Attabiyyat (35°30'24" N,35°46'49" E) in the south-western Latakia city, Syria. Mites were removed from leaves using the "dipping-checking-washing-filtering" method (Boller, 1984). For collecting mites from litter, materials were placed on a sieve (25 cm Ø x 10 cm; its screen with 5 mesh/cm) and shaken over a black plastic sheet (1.5 m 2 ). Collected mites were cleared in lactic acid for 48 hours, mounted on slides in Hoyer's medium, and then dried in an oven at 40°C for three days.

Mite observation and description
The specimens were examined using an Olympus® CH20 microscope. Measurements were realized using the scale of a reticle installed on the eyepiece lens. Mite body parts of specimens were pictured using a mobile phone camera (13 megapixels) fixed on the eyepiece lens and images were transferred to the professional quality vector graphics software Inkscape ® 0.92 installed on a computer for drawing with the aid of the computer's mouse.
All measurements are given in micrometers (µm) and the setal nomenclature used in the description follows Lindquist (1985). The holotype measurements are followed by measurements of the range of paratypes in parentheses. In addition to the key body measurements such as the distance between setae v 2 and setae h 1 and members of setae sc 2 (Saito et al., 1999), body length representing the distance between the tip of palps to the end of idiosoma and body width representing the widest transverse part of the hysterosoma, are also provided. The distance between two setae was measured as the distance from the center of one setal base to the other. Legs were measured from coxae to the distal margin of tarsi (excluding claws and empodia). Leg setal counts are given in the order: coxa-trochanter-femur-genu-tibia-tarsus. Numbers of setae refer to tactile setae, solenidia are given in parentheses and alternative counts are given in brackets. When asymmetry in number of setae on a leg segment was present, only the maximal number was considered.

Systematics
Family Tetranychidae Donnadieu, 1875Subfamily Bryobiinae Berlese, 1913Tribe Bryobiini Reck, 1952Genus Bryobia Koch, 1836 Bryobia (Allobia) nikitensis Livshits and Mitrofanov, 1969 Two female specimens of this species were recorded on a new host plant: it was found on Salvia verbenaca L., Attabiyyat, south-west of Latakia city, Syria (35°30'24" N, 35°46'49" E, 23 April 2019). This species has been previously collected from Sarcopoterium spinosum (L.) in Syria (Barbar, 2018;Zeity and Srinivasa, 2019). Diagnosis -This species belongs to Bryobia (Allobia) Livshitz and Mitrofanov (1971) which is characterized by the following: propodosomal lobes absent or poorly developed, if present, outer and inner lobes not separated by deep incision; distance between f 1 members longer than distance between f 2 members; f 1 and f 2 well separated laterally. It can be distinguished from others Byrobia species by a combination of the following characteristics: females with weakly developed median propodosomal lobes with small and shallow incision, outer lobes reduced to very small tubercles; setae v 2 about twice as long as setae v 1 ; dorsal body setae short, spatulate, serrate and inserted in small tubercles; peritreme ends in a tiny anastomosis consisting of 3-4 loges; tarsus III with tactile seta and solenidion subequal in length forming duplex; tarsus IV with solenidion well-separated from tactile, proximal, about 3/4 the length of tactile; leg I shorter than body length, empodial claws I-IV uncinate, each with one pair of tenent hairs; empodium I with one pair of tenent hairs and empodia II-IV with two rows of tenent hairs.
Dorsum -Prodorsum with four pairs of setae ( Figure 1A); median propodosomal lobes weakly developed with fused base (variations in propodosomal lobes due to mounting are presented in Figure 2A-C); outer propodosomal lobes reduced to small tubercles; setae v 2 about twice as long as setae v 1 (Figure 2). Distance between members of first (v 1 ) and second (v 2 ) pair of propodosomal setae insertions 10 (8-12) and 47 (45-50), respectively. Dorsal body setae short, spatulate and serrate, 12-17 width, subequal in length except for v 1 far smaller, inserted on small tubercles ( Figure 1B Setae f 1 and f 2 lateral, distance between f 1 members larger than between f 2 members. Dorsal body surface granulated with longitudinal and irregular folds on propodosoma ( Figure 2D) and with transverse spaced granulate striae on medial hysterosoma irregularly arched posteriorly ( Figure 1).
Etymology -This species was named after the country, Syria, where it was collected.
Bryobia (Bryobia) watersi Manson, 1967 The specimens of this species were identified as Bryobia sp. and misidentified as B. (B.) graminum and/or B. (B.) kissophila in previous studies (Barbar, 2014(Barbar, , 2018. This was Among the specimens of B. (B.) watersi mentioned above, two females collected from A. retroflexus have only three propodosomal lobes each with a single seta (Figures 15 A-B). Initially, the specific identification of these specimens led to a result that they are either new specimens (or closely related species) of the two "trilobed" species B. bakeri Zaher et al. (1982)  and B. aegyptiacus Zaher et al. (1982) or they are aberrant Bryobia specimens. Actually, the overall propodosomal lobe shapes of the trilobed Syrian specimens are closer to those of B. bakeri ( Figure 15A) than those of B. aegyptiacus. Nevertheless, the Syrian specimens differ from those two species by the palptarsus setal count [unusual counts are found in the two species described by Zaher et al. (1982)] and by small differences in the global leg setal counts. These results led to conclude that the Syrian trilobed specimens did not belong to B. bakeri nor to B. aegyptiacus. Indeed, despite the differences between the propodosomal lobes of the specimen presented in Figure 15B (typical of abnormal "asymmetrical" lobes; the outer lobe of the left side is obviously missing) and those of the specimen presented in Figure 15A (the axis of symmetry passes through the middle of the single inner lobe), we concluded that these females are abnormal individuals of B.  (Arabuli and Auger, 2016;Fashing et al. 2016;Smiley and Baker, 1995).
This variability in the propodosomal lobe shape found in the two Syrian trilobed individuals of B. (B.) watersi guided us to question about the taxonomical value of the number of propodosomal lobes used to separate B. bakeri and B. aegyptiacus from other Bryobia species. Several arguments tend to show that these specimens could be teratological forms rather than species with a particular propodosomal lobes pattern: (1) Specimens are rare: like the Syrian trilobed specimen of B. (B.) watersi of the Figure 15A, only one specimen of B. bakeri and one of B. aegyptiacus are known. Although Smiley and Baker (1995) reported a possible additional female of B. bakeri, it could belong to another species because its leg setal count is far different from that of the type specimen of B. bakeri (it shares the same setal count only on five leg articles; as a comparison, the Syrian trilobed B. (B.) watersi are closer to B. bakeri for the reason that they share the same setal count on 12 leg articles).
(2) Specimens with three propodosomal lobes (each bearing one seta) are known to occur in several species of Bryobia: Smiley and Baker (1995) mentioned that in a few species of  Bryobia some aberrant females (with two or three propodosomal lobes) appear sometimes. Since that work, several cases of Bryobia species with three propodosomal lobes have been reported (Arabuli and Auger, 2016;Fashing et al. 2016). In the detailed study by Fashing et al. 2016, it was demonstrated that both morphotypes (with three or four propodosomal lobes) of Bryobia abyssiniae Fashing and Ueckermann, 2016 belong to the same species, and about 9.5% of observed specimens had a single propodosomal inner lobe (with a single seta v 1 ). (3) The two Syrians trilobed specimens are conspecific despite the fact that one of them is obviously an aberrant form (asymmetry) and the other has a symmetrical propodosomal lobe pattern similar to that found in B. bakeri.
This tends to show that a bryobiine mite with an unpaired inner propodosomal lobe bearing a unique seta v 1 , can be an aberrant specimen despite a symmetrical propodosomal trilobed lobe pattern.
In our opinion, all these elements together strongly suggest that B. bakeri and B. aegyptiacus would be more aberrant individuals of two species of Bryobia (four-lobed) than species characterized by unpaired inner propodosomal lobe. Even if the data are insufficient to assign these "trilobed" species to an existing four-lobed Bryobia species, the demonstration presented here is consistent with the synonymy of the genus Septobia with the genus Bryobia by Bolland et al. (1998).