Evaluation of methods to control Phytonemus pallidus and Anthonomus rubi in organic strawberry production

Abstract

Use of the predatory mite Neoseiulus cucumeris (Oudemans) (Acari, Phytoseiidae) and a fleece cover in combination with pyrethrum application showed potential for control of two important pests in organic production of strawberry (Fragaria · ananassa Duch.), although there were some unexpected interactions between pyrethrum and the release of N. cucumeris that need to be investigated further. Two cultivars, Honeoye and Cavendish, were treated with pyrethrum with or without fleece to control strawberry blossom weevils [Anthonomus rubi Herbst. (Col., Curculionidae)] and N. cucumeris was released to control strawberry mites [Phytonemus pallidus (Banks) (Acari, Tarsonemidae)]. Number of strawberry mites, number of flower buds damaged by the weevil, incidence of grey mould and powdery mildew, and fruit yield were measured in two consecutive fruiting seasons. In Honeoye, the fleece in combination with pyrethrum decreased the proportion of damaged buds by 11-23% and increased yield by 49-91 g per plant. When pyrethrum was used alone it did not influence the number of damaged buds or yield. This indicates that the combined treatment was more effective because of the fleece. In Cavendish, the fleece and pyrethrum treatments were not found to be effective. Almost no P. pallidus was found in Honeoye and the results were not analysable. In plots with Cavendish where N. cucumeris had been released, there were approximately 50% fewer P. pallidus from the end of August onwards in 2003. However, this response did not significantly influence the succeeding year's yield. The number of fruits infected with fungi was very low and no effects were observed for any of the treatments.

Control of Phytonemus pallidus (Acari: Tarsonemidae) from strawberry transplants using controlled atmosphere temperature treatment

“…The lack of registered miticides is also a concern for strawberry growers since relying on just one or few active ingredients for pest control can increase the risks of resistance development (AAC 2021). Introductions of predatory mites (Acari: Phytoseiidae) such as Neoseiulus cucumeris , N. californicus , or N. fallacis can prevent the build-up of P. pallidus populations (Croft et al 1998, Easterbrook et al 2001, Berglund et al 2007, Tuovinen and Lindqvist 2010). However, they cannot eradicate cyclamen mite on whole plants (Fitzgerald and Easterbrook 2003, Fitzgerald et al 2007), and release rates required to maintain adequate control in strawberry fields under field conditions were too high to be cost-effective for growers (Patenaude et al 2020).…”

The temporal distribution of cyclamen mite, Phytonemus pallidus (Acari: Tarsonemidae), in strawberry and comparison of sampling methods

“…Cyclamen mite is commonly sampled by removing young, folded strawberry leaves, holding them open under a stereomicroscope, and counting all life stages on the adaxial and abaxial surfaces (e.g., Fitzgerald et al 2008;Fountain et al 2010;Labonowska et al 2015;Patenaude et al 2020). In some cases, motiles (adults and larvae) but not eggs have been counted (e.g., Berglund et al 2007). Extracting mites from plant material for preservation and counting in a fluid may be advantageous because leaves cannot be stored for long periods of time.…”

Cyclamen mite (Acari: Tarsonemidae) monitoring in eastern Canada strawberry (Rosaceae) fields and its potential control by the predatory miteNeoseiulus cucumeris(Acari: Phytoseiidae)

“…supply companies, and the most studied. Indeed, its effectiveness against this pest has been known for more than 60 years (Huffaker and Kennett 1953), and, despite great variability, has been demonstrated in many studies (Croft et al 1998;Easterbrook et al 2001;Berglund et al 2007;Petrova et al 2008;Svensson 2008;Tuovinen and Lindqvist 2010). However, as N. cucumeris is known to be sensitive to cold temperatures (Gillespie and Ramey 1988;Jones et al 2005;Svensson 2008) and most studies originate from countries where this predatory mite often overwinters, its efficacy and survival under the Canadian climate remain unknown.…”