Euseius gallicus Kreiter & Tixier, 2010

Farazmand, Azadeh, Jalaeian, Mahdi, Kamali, Hashem, Saboori, Alireza, Tixier, MarieStéphane & Kreiter, Serge, 2023, Phytoseiidae (Acari: Mesostigmata) in four provinces of Iran, Persian Journal of Acarology 12 (1), pp. 21-58 : 37

Euseius gallicus Kreiter & Tixier, 2010

Euseius gallicus Kreiter & Tixier in Tixier et al. 2010: 242 .

Specimen examined – one ♀ and one ♂ study. Razavi Khorasan Province – one ♀, Mashhad (1027 m aasl, 59° 32′ 40.01′′ E, 36° 19′ 33.82′′ N), on Juglans regia L. ( Juglandaceae ), 14.X.2020; one ♂, Rasht (3 m aasl, 49° 35′ 33′′E, 37° 16′ 50.87′′ N), on Parrotia persica (De Candolle) Meyer (Hamamelidaceae) , 28.VII.2020.

World distribution – Belgium, France, Germany, Italy, Mauritius, The Netherlands, Slovenia, Tunisia, Türkiye.

Remarks – This species is a new record for Iran. Morphological and morphometric characters fit well previous measurements published in the original description ( Okassa et al. 2009; Tixier et al. 2010) and in a further paper ( Döker et al. 2014). The female and the male collected were compared to females and males collected in various countries and present in the collection of CBGP.

Authors of E. gallicus have reported in the original descriptions of that species the comparison with Euseius longiverticalis (Liang & Ke) , Euseius kirghisicus (Kolodochka) and then by Döker et al. 2014 with Euseius ucrainicus (Kolodochka) , especially in idiosomal setae length. But E. gallicus differs from this latter in the peritreme length and spermatheca shape. Furthermore, when E. gallicus was described, the descriptors have asked the opinion of Dr. Kolodochka in Ukraine for him checking the new status of this new species in relation to those he already described, i.e. E. kirghisicus , and E. ucrainicus (Tixier pers. comm. 2014 and cited in the original description).

One close species of Euseius gallicus has been reported from Iran ( Rahmani et al. 2010; Panahi et al. 2014; Hajizadeh and Mortazavi 2015): Euseius amissibilis Meshkov. Euseius amissibilis was described from Tajikistan, on Platanus orientalis L. When describing E. gallicus, Tixier et al. (2010) provided main differences between these two species: the lengths of setae Z1, JV5 and to a lesser extent j1, j3, S5 and stIV. The lengths of JV5 and S5 are much longer in E. gallicus than in E. amissibilis , while Z1 is shorter in E. gallicus ( Table 7). The fixed digit of E. amissibilis has two teeth instead of five as in E. gallicus (and this character is stable in this species) even if on the drawings of the original description, E. amissibilis seems to have more than two teeth on the fixed digit and perhaps more than five. The specimens presently considered from Iran, males and females, were compared to Euseius gallicus type material and additional material from several various localities in Europe and morphological characters and measurements are identical, with only very slight variations. When we observed the data provided in the two re-descriptions of E. amissibilis from Iran ( Rahmani et al. 2010; Hajizadeh and Mortazavi 2015) ( Table 7), it seems that these specimens have measurements closer to E. gallicus than to E. amissibilis . Hajizadeh and Mortazavi (2015) noted also the presence of 5 teeth of the fixed digit. In both re-descriptions, nothing is provided concerning the similarity between E. gallicus and E. amissibilis . Rahmani et al. (2010) who provided the first report of E. amissibilis from Iran, provided a diagnosis based on one specimen with only dorsal morphology available.

Because intraspecific variation exists in seta lengths (Tixier 2012), some minor doubts could remain on the synonymy between these two species. So at this state, two hypotheses could be provided (i) all specimens from Iran identified belong to E. amissibilis and E. gallicus and E. amissibilis are synonyms or (ii) all specimens from Iran belong to E. gallicus and E. amissibilis is a different species. We here consider the second hypothesis, (i) because of the complete description (morphological and molecular features) ( Okassa et al. 2009; Tixier et al. 2010) of E. gallicus and (ii) because without type observation (type material loan is impossible with the original country of description) and molecular data, it is not possible to valid the first hypothesis and the non-reliability of the characters distinguishing these two species. Further experiments using molecular data would be useful to conclude about potential synonymies.