Managing Bees for Delivering Biological Control Agents and Improved Pollination in Berry and Fruit Cultivation

Abstract

<p>Targeted precision biocontrol and improved pollination were studied Europe-wide in the EU ERA-NET CORE ORGANIC 2 project BICOPOLL (Biocontrol and Pollination). A case study was conducted on the management of strawberry grey mold <em>Botrytis cinerea</em>, with the biocontrol fungus, <em>Gliocladium catenulatum</em>, vectored by honey bees or bumble bees. A joint field trial carried out in five countries targeted strawberry cultivations in open field, and included four treatments: untreated control, chemical fungicide, entomovectored biocontrol, and chemical and biocontrol combined. In organic fields, no pesticide treatments were included. The proportion of moldy berries, and/or the marketable yield of healthy berries were recorded from each treatment, along with other parameters of local interest. A pilot study was started in Finland in 2006, and, by 2012, large commercial farms were using entomovectoring. In 2012, field trials were started in Estonia and in Italy, and in 2013-14, these experiments were expanded to Slovenia and Turkey. In total, 26 field tests were conducted using entomovectoring and <em>Gliocladium catenulatum</em> (Prestop<sup>®</sup> Mix) on strawberry, with five additional trials on raspberry. Efficacy results have been excellent throughout the field studies. The results show crop protection equalling or exceeding that provided by a full chemical fungicide program, under all weather conditions, and over a wide geographical range (from Finland to Turkey). Under heavy disease pressure, entomovectoring provided on average a 47% disease reduction, which was the same as multiple fungicide sprays. Under light disease pressure, biocontrol decreased grey mold by an average of 66%, which was greater than fungicide sprays. The concept has proven to be effective on strawberries, raspberries, pears, apples, blueberries, cherries, and grapes. A conservative estimate for Finland is that over 500 ha of strawberry cultivation currently use the technique (≈15% of the strawberry growing area). To make full use of the entomovectoring technique, organic berry and fruit growers are encouraged to (i) keep bees, or to hire the service from local beekeepers for entomovectoring; and (ii) manage vegetation within and around the target crop to support the activity of bees and other pollinators, which can help to disseminate the beneficial microbial populations within the crop. Beekeepers are encouraged to (i) market pollination and biocontrol services to fruit and berry growers, and (ii) ensure that all operations are effective in mananging bees and their microbe dissemination activity. Biocontrol product manufacturers are encouraged to further develop products and their formulations specifically for entomovectoring, because current formulations are suboptimal as they are initially optimized for other uses (e.g., mixing into the soil).</p>

Developing ecostacking techniques for pollen beetle management in oilseed rape

“…Planting of crops in proximity can improve pollination and pest control, provide habitat for farmland biodiversity, and maximize use of space to increase overall crop productivity (Skellern and Cook 2018). Trap crops (Hokkanen et al 1986;Hokkanen 1991; Shelton and Badenes-Perez 2006) can be used directly for pest management, and can facilitate optimally timed delivery of emerging biocontrol technologies such as entomovectoring with insect pathogens (Hokkanen and Menzler-Hokkanen 2007;Hokkanen et al 2015) and RNAi-products (Hokkanen and Menzler-Hokkanen 2018c). Timing in this context is critical, and trap cropping in the spring as well as in the autumn needs to be considered.…”

“…Usually, managed pollinating insects such as honey bees and bumble bees are employed as vectors; hence the term "entomovector technology" (first used by Hokkanen and Menzler-Hokkanen 2007). The vectoring insects are loaded with the powdery biocontrol preparate at the exit from their hive, and while visiting the flowers of the target crop, they deliver the biocontrol agent onto the crop inflorescences (Hokkanen et al 2015). As pollen beetles feed in open flowers, they are good targets for entomovectoring, because rapeseed flowers are highly attractive also to pollinators.…”

“…Experience so far shows that bees are more efficient than conventional sprayers in delivering the EPF inoculum to the pest infested flowers (Butt and Copping 2000). Entomovectoring improves targeting and provides cost-effective control of pests (see also Hokkanen et al 2015), and can be adopted for improving pest management in rapeseed.…”

Safety of Prestop® Mix to pollinators: a critical review of its properties and use in entomovectoring. Response to the article by Karise et al. (2015)

“…In entomovectoring, either managed honey bees or managed bumble bees are used to disseminate the biocontrol agents (Hokkanen et al 2015). These managed insects are of course important pollinators where they are deployed, but they are reared and managed by humans.…”

“…Professional strawberry growers in Finland have been using entomovectoring with honey bees since 2006, and currently hundreds of growers employ the method for grey mould control (Hokkanen et al 2015). Many growers also have experimented with bumble bees as vectors of Prestop Ò Mix.…”