Phytoseiulus persimilis Athias-Henriot, 1957

Kreiter, Serge, Payet, Rose-My, Douin, Martial, Fontaine, Olivier, Jacques, Fillâtre & Bellec, Fabrice Le, 2020, Phytoseiidae of La Réunion Island (Acari: Mesostigmata): three new species and two males described, new synonymies, and new records, Acarologia 60 (1), pp. 111-195 : 135-138

Phytoseiulus persimilis Athias-Henriot

Phytoseiulus persimilis Athias-Henriot 1957: 347 ; Moraes et al. 1986: 109; Moraes et al. 2004a: 169; Chant & McMurtry 2006a: 20; 2007: 55.

Phytoseiulus (Phytoseiulus) persimilis, Wainstein 1962: 17 .

Typhlodromus persimilis, Hirschmann 1962: 75 .

Phytoseiulus riegeli Dosse 1958: 48 (synonymy according to Chant 1959); Phytoseiulus tardi Lombardini 1959: 166 (synonymy according to Kennett & Caltagirone 1968).

Sources of measurements – For ♀♀: Africa ( Benin 1♀, Kenya 1♀, Uganda 2♀♀): Moraes et al. (2007); Senegal: Kade et al. (2011); South Africa: van der Merwe (1968); Holotype Zaïre: Moraes et al. 1989). For ♂♂: South Africa: van der Merwe (1968). -: not provided. Phytoseiulus persimilis is a Mediterranean/subtropical predatory mite, a type I species, i.e. a specialist predator of the urticae species group of the genus Tetranychus ( McMurtry and Croft 1997; McMurtry et al. 2013). Considerable research has been conducted on this predator-prey interaction (see review by Kostiainen and Hoy 1996), and numerous biological control programs have used P. persimilis against T. urticae on a wide range of ornamental and vegetable crops. Phytoseiulus persimilis was the first greenhouse biological control agents available commercially and it is one of the most successful BCA in the world. It can also be used in temperate climates on open-field crops such as strawberries. Optimum conditions are 20-27 °C and relative humidity of 60-90 %. Cooler or warmer temperatures may have a negative effect on reproduction, development and efficiency of this predatory mite. This species is present in Mauritius ( Kreiter et al. 2018a) and La Réunion probably because of its commercial introduction and uses in vegetable and ornamental greenhouses, dispersion of some specimens released and establishment in the environment. This species is actually reared and sold in La Réunion and commercialised in Mascareignes since a long time (Quilici, personal communication). Phytoseiulus persimilis was already known from La Réunion ( Quilici et al. 1997, 2000). Exact indications of locations were provided in these papers but without any measurements of specimens collected. Measurements of specimens collected during this study are provided in Table 13 .

Specimens examined: 5 ♀♀ in total, all measured. Montvert-les-Hauts – EARL Le Mont Vert farm (aasl 582 m, Long 55°32’19” E, Lat 21°19’42” S), 1 ♀ on Fragaria sp., 3 ♀♀ on E. sonchifolia , 4/8/2015 ; Le 19 e – Plaine des Caffres, JL Robert farm (aasl 1000 m, Long 55°32’9” E, Lat 21°14’16” S), 1 ♀ on Phytolacca americana L., 15/12/2015 .

Remarks: measurements of morphological characters ( Table 13 ) of the 5 females fit well with measurements found in the literature, especially with those of specimens collected recently in Mauritius ( Kreiter et al. 2018a), and particularly for setae j4, J5, z2, z5 and r3. Some setae are slightly shorter in La Réunion specimens compared to specimens from other countries, mainly for the long setae of this species (j6, s4, Z1, Z4, and Z5). Some other shorter setae of this species, for example R1 and macrosetae of the leg IV are also shorter in La Réunion specimens. Nevertheless, these findings are questionable given that only five females of P. persimilis have been measured compared to measurements of 14 females collected in Mauritius and to large numbers of specimens from other countries.