Typhlodromus pyri Scheuten, 1857

NovljanK, Monica, K, Tanja Bohinc, KreiterK, Serge, K, Ismail Döker & TrdanK, Stanislav, 2023, The indigenous species of predatory mites (Acari: Phytoseiidae) as biological control agents of plant pests in Slovenia, Acarologia 63 (4), pp. 1048-1061 : 1056-1057

Typhlodromus pyri Scheuten

Typhlodromus pyri ( Figure 7 ) was described by Scheuten in 1857 based on the material collected from Pyrus communis L. ( Rosaceae ) in Bonn, North Rhine-Westphalia, Germany. It is a cosmopolitan species and its natural populations have been reported in over 40 countries around the world ( Demite et al. 2023). In addition, it is also reared on a commercial scale and available in international markets since 1990 ( Knapp et al. 2018). It was found to be the most dominant species in intensive apple orchards in Slovenia between 1997 and 2003 ( Miklavc and

Milevoj 2007).

According to McMurtry et al. (2013), T. pyri is a type IIIa generalist predator that lives on pubescent leaves. It can feed and reproduce on several food sources such as grapevine leaf rust mite Calepitrimerus vitis (Nalepa) , European red mite, two-spotted spider mite, and grape erineum mite Colomerus vitis (Pagenstecher) , as well as on several plant pathogenic fungi

( Zemek and Prenerovâ 1997 ; Pozzebon and Duso 2008 ; UVHVVR 2022b). Despite its ability to feed on plant tissues and produce some apparent scars on apple leaves and fruits, the damage caused by this predator is considered minor and without economic importance ( Sengonca et al.

2004).

Miklavc (2006) conducted a comprehensive study on the life cycle T. pyri fed with European red mites and brown almond mites Bryobia rubrioculus (Scheuten) . They showed that around

8-10 days period is needed for the development T of. pyri from eggs until the end of the deutonymph stage, for both males and females irrespective of the diet. The lifespan of T. pyri females on both diets was similar, i.e. 27.5 days on P. ulmi and 25.4 days on B. rubrioculus .

Also, one single female adult produces up to 17 eggs, with average oviposition of 6.94 and 8.33

eggs per female insect, consecutively on P. ulmi and B. rubrioculus diets.

Zacharda and Hluchy (1997) reported the success of T. pyri as a biological agent against two-spotted spider mites in greenhouse strawberries. It was introduced with a predator: prey ratio of 1:10. After two weeks of release, the population density of active instars of T. urticae was reduced by 50%. The introduction T of. pyri was done in early April, and then this biological control agent protected the strawberry plants for at least six weeks before T. urticae population started to slightly increase. A more recent study by Lorenzon et al. (2018) reported the successful control of spider mites, Eotetranychus carpini (Oudemans) and P. ulmi in a vineyard in Veneto, Italy. The control was successfully conducted by the release T of. pyri ,

with or without the addition of another predatory mite Kampimodromus aberrans (Oudemans) .

However, the presence of T. pyri reduced the population of the naturally occurring predatory mite A. andersoni , suggesting intraguild predation T of. pyri to the resident phytoseiid*.

Figures

Figure 7 Adult female ofTyphlodromus pyri preying on a two-spotted spider mite female (photo: Institut Agro Montpellier).