Amblyseius eharai Amitai & Swirski, 1981

Tixier, Marie-Stephane, Auger, Philippe, Migeon, Alain, Douin, Martial, Fossoud, Amandine, Navajas, Maria & Arabuli, Tea, 2021, Integrated taxonomy supports the identification of some species of Phytoseiidae (Acari: Mesostigmata) from Georgia, Acarologia 61 (4), pp. 824-844 : 826-828

Amblyseius eharai Amitai & Swirski

Amblyseius eharai Amitai & Swirski 1981: 60 .

Specimens examined. At Lanchkhuti, Grigoleti (42.0192° N, 41.7629° E): 10 ♀♀ and 2

♂♂ on Rubus sp. (Rosaceae) , one ♀ on Citrus trifoliata (L.) Rafinesque ( Rutaceae ).

Previous records. China, Hong Kong, Japan, Malaysia, South Korea, Taiwan, Thailand.

Measurements of females (5 specimens)

Dorsum. Dorsal shield 362 (340–400) long and 199 (188–212) wide, smooth, with seven pairs of solenostomes (gd1, gd2, gd4, gd5 not well visible, gd6, gd8 and gd9), 17 pairs of dorsal setae and two pairs of sub-lateral setae: j1 35 (32–37), j3 44 (42–45), j4 4 (2–5), j5 4 (2–5),

j6 4 (2–5), J2 4 (2–5), J5 4 (2–5), z2 7, Z1 5, z4 4 (2–5), z5 4 (2–5), Z4 104 (100–110), Z5

255 (250–262), s4 98 (97–100), S2 5, S4 7, S5 5, r3 11 (10–12) and R1 7 in length. All setae smooth.

Peritreme. Extending forwards to the bases of the setae j1.

Venter. Sternal shield with three pairs of setae and two pairs of poroids; one pair of sternal setae (st4) on small metasternal platelets; posterior margin with a truncated median projection. Distances between st1–st3 67 (65–70), st2–st2 70 (67–72), st5–st5 72 (70–77). Two pairs of metapodal plates, the largest one 19 (17–22) long and 6 (5–7) wide, the smallest one 8 (7–10)

long and 2 wide. Ventrianal shield with three pairs of pre-anal setae JV1, JV2, ZV2 and pre-anal crescent pores (gv3) present, just under the setae JV2. Integument surrounding ventri-anal shield with four pairs of setae ZV1, ZV3, JV4 and JV5 ; ventri-anal shield 109 (100–130) long,

57 (55–62) wide at level of anterior corners, and 72 (67–77) wide at level of anus. JV5 64 (60–67) long.

Legs. Legs IV with three macrosetae: on the genu 126 (120–130), tibia 90 (85–95) and basitarsus 62 (60–65). SgeI 46 (42–47), SgeII 39 (37–42), SgeIII 47 (45–50), StiIII 36 (32–37). Genu II with seven setae (2–2/0, 2/0–1), Genu III with seven setae (2–2/0, 2/0–1).

Chelicera. Fixed digit 47, movable digit 42. Dentition not visible because the chelicerae are closed, but the fixed digit is clearly multidentate.

Spermatheca. Spermatheca with elongate cervix 21 (20–22) long, distal two-thirds gradually flaring, round atrium.

Remarks. Amblyseius eharai is morphologically close to A. herbicolus (Chant) . Seta lengths are clearly overlapping and do not allow differentiating between these two species ( Table 2). The only clear differences are the shape of the posterior border of the sternal shield (straight for A. herbicolus and with a truncated median projection for A. eharai ) and the length and shape of the cervix of the spermatheca (long (23–29), distal two-thirds gradually flaring to 2–2.5 times basal diameter in A. herbicolus and short (18–24), flaring distally to 2–3 times narrowest diameter in A. eharai ) ( McMurtry and Moraes 1984). Because of these minor differences and because of the distribution A of. eharai only reported from Asia (whereas A. herbicolus is a cosmopolitan species), molecular markers were applied to assess further the identity of the Georgian specimens. Six DNA sequences (three sequences for CytB mtDNA, and three sequences for the COI mtDNA) were obtained from three specimens. The COI sequences were blasted in the Genbank database and were clearly assigned A. eharai to. Table 4a shows the COI genetic distances between the Georgian specimens and Amblyseius largoensis (Muma) , A. herbicolus and A. eharai . The COI mtDNA sequences of the three Georgian specimens are identical (0%). They differ from A. largoensis and A. herbicolus sequences in Genbank by high genetic distances (27.2 and 29.2%, respectively), and from the 15 DNA fragments of A. eharai retrieved from Genbank by very low distances (2.1–3.2%), corresponding to intraspecific variation. The phylogenetic tree also illustrates that the Georgian specimens belong to the clade including the 15 DNA sequences retrieved from Genbank and assigned A. to eharai ( JX080331 – JX080345 ) (figure 1). No CytB mtDNA sequence of A. eharai is available in Genbank, whereas they are for A. herbicolus and A. largoensis (Supplementary Table S1b). The CytB genetic distances between the specimens herein considered and A (i.) herbicolus range between 39.1% and 40.3%, and (ii) A. largoensis range between 42.7% and 44.5%, clearly showing that Georgian specimens do not belong to these two latter species. Thus, based on morphological characteristics and molecular data, we conclude that the Georgian specimens belong to the species A. eharai .

It is the first time that this species is reported from this country and outside eastern Asia.

In this survey, it was reported on Rubus sp. and Citrus trifoliata (L.) Rafinesque both at Lanchkhuti (near the Black Sea coast). Its unexpected presence in Georgia could be due to introduction from eastern Asia, as C. trifoliata is a species originating from Korea and north of China. Because A. eharai was also found on Rubus sp. , it is possible that this species has adapted to new plants after its introduction into the region. Amblyseius eharai is considered to be an efficient natural enemy of mite pests and thrips in various crops, included citrus orchards (i.e. Ji et al. 2013, Park & Lee 2020).