Euseius gallicus Kreiter & Tixier, 2010

Kreiter, Serge, Amiri, Karima, Douin, Martial, Bohinc, Tanja, Trdan, Stanislav & Tixier, Marie-Stéphane, 2020, Phytoseiid mites of Slovenia (Acari: Mesostigmata): new records and first description of the male ofAmblyseius microorientalis, Acarologia 60 (2), pp. 203-242 : 224-225

Euseius gallicus Kreiter & Tixier

Euseius gallicus Kreiter & Tixier , in Tixier et al. (2010 d): 242.

Euseius gallicus is a phytoseiid species described from southern France ( Tixier et al. 2010). It has also been recorded from Tunisia, Belgium, Germany, the Netherlands, and Turkey ( Kreiter et al. 2010; Döker et al. 2014).

Unlike the phytoseiid species mentioned above, which are classified as generalist predators of small insects and mites (type III), Euseius species are pollen-feeding generalist predators (type IV) ( McMurtry and Croft 1997; McMurtry et al. 2013). Type III phytoseiids also feed on pollen but prefer or show better performance on insect or mite prey. Type IV predatory mites have their highest reproductive capacity when feeding on pollen, and populations in the field often increase significantly when the crop or the surrounding vegetation is flowering ( McMurtry et al. 2013).

Recently, E. gallicus has shown potential as a biocontrol agent for thrips and whiteflies in roses when Typha sp. (cattail) pollen is supplied as an additional food source ( Biobest 2013; Wackers 2013). Provision of pollen as a supplementary food source can improve biological control of whiteflies and thrips by type III phytoseiids ( van Rijn and Sabelis 1993; Nomikou et al. 2010), and control works excellently in crops where pollen is naturally available ( Calvo et al. 2012). The population of Euseius species can grow faster than the population of type III phytoseiids when pollen is provided as a food source.

This species was already recorded and mentioned in a Slovenian paper ( Bohinc et al. 2018) but it is the first mention of that species in an international paper for Slovenia.

World distribution: Belgium, Czech Republic, France, Germany, Italy, the Netherlands, Tunisia, Turkey.

Specimens examined: 30 ♀♀, 4 ♂♂ and 4 immatures in total. Parecag (aasl 72 m, lat. 45°28’44”N, long. 13°37’49”E), 1 ♀ on Diospyros kaki Thunberg (Ebenaceae) , 21/VI/2018; Dragonja (aasl 1 m, lat. 45°27’12”N, long. 13°39’43”E), 1 ♀ on Pistacia terebinthus L. ( Anacardiaceae ), 21/VI/2018; Lucija (aasl 22 m, lat. 45°30’30”N, long. 13°36’11”E), 1 ♀ and 1 immature on Cucumis sativus L. ( Cucurbitaceae ), 11/VII/2018; Ljubljana, Hotel Katrca (aasl 307 m, 46°3’19”N, 14°20’26”E), 2 ♀♀ on Physocarpus opolifolius (L.) Maximowicz ( Rosaceae ) and 1 ♀ and 1 immature on Carpinus betulus L. ( Betulaceae ), 18/VI/2019; Sečovlje, 58a (aasl 3 m, lat. 45°28’43”N, long. 13°37’28”E), 13 ♀♀, 4 ♂♂ and 1 immature on Cornus sanguinea L. ( Cornaceae ) and 3 ♀♀ on Aesculus hippocastanum L. ( Hippocastanaceae ), 19/VI/2019; Bertoki (aasl 28 m, lat. 45°32’55”N, long. 13°47’13”E), 3 ♀♀ on Prunus persica L. ( Rosaceae ) and 1 ♀ on Actinidia deliciosa (A. Chevalier) C.F. Liang & A.R. Ferguson (Actinidiaceae) , 19/VI/2019; Ankaran (aasl 19 m, lat. 45°34’20”N, long. 13°45’29”E), 3 ♀♀ and 1 immature on Quercus robur L. ( Fagaceae ), 19/VI/2019; Ljubljana, Hotel Katrca (aasl 307 m, 46°3’19”N, 14°20’26”E), 1 ♀ on Tilia platyphyllos Scopoli (Malvaceae) , 22/VI/2019.

Remarks: The measurements of the adult females collected agree with those provided by Okassa et al. (2009), Tixier et al. (2010) and Döker et al. (2014).