Reduced-risk management strategy for insect pests of berry crops

For inquiries please contact:
Pest Management Centre, Agriculture and Agri-Food Canada (AAFC)
aafc.pmcinfo-clainfo.aac@agr.gc.ca

May 2017

Preface

Pesticide risk reduction strategies are developed under Pesticide Risk Reduction (PRR) of Agriculture and Agri-Food Canada's (AAFC) Pest Management Centre. To reduce undesirable impact of the use of pesticides in agriculture, PRR works with grower groups, industry, provinces, researchers and regulators to identify gaps in pest management and opportunities to develop and implement strategies to address these.

A pesticide risk reduction strategy is a detailed plan that aims to address grower needs for reduced-risk management tools and practices for specific pest issues. The strategies are developed through extensive consultation with stakeholders. The strategy document presented here summarizes the framework and activities supported by PRR. It is intended to provide an update on the progress in developing and implementing the strategy and new tools and practices made available through this process.

For more information, please visit the Pest Management Centre.

Acknowledgement

Pesticide Risk Reduction acknowledges the contribution of participating organizations and stakeholders, including the current and former members of the Insect Pests of Berry Crops Working Group:

Tracy Hueppelsheuser and Carolyn Teasdale - British Columbia Ministry of Agriculture
Karina Sakalauskas - British Columbia Blueberry Council
Sheila Fitzpatrick - AAFC, British Columbia and Debra Moreau - AAFC, Nova Scotia
Blaine Staples - Grower, Alberta
Anthony Mintenko - Manitoba Ministry of Agriculture, Food and Rural Department
Pam Fisher and Hannah Fraser - Ontario Ministry of Agriculture, Food and Rural Affairs
Kevin Schooley - Ontario Berry Growers Association
Jean-Philippe Legaré, Guy-Anne Landry, Liette Lambert and Stephanie Tellier - Ministry of Agriculture, Fisheries and Food of Quebec
Annabelle Firlej - Institute for Research and Development in Agro-environment (IRDA)
Jennifer Crawford, Vincent Méthot and Yourianne Plante - Quebec Strawberry and Raspberry Growers Association
Jennifer Haverstock and Peter Burgess - Perennia
Chris Cutler - Dalhousie University, Nova Scotia
Chris Maund - New Brunswick Department of Agriculture, Aquaculture and Fisheries
Chris Jordan - Prince Edward Island Department of Agriculture and Fisheries
Terry Counter - PMRA, Health Canada

Executive Summary

Many insect species causing feeding damage to plants can be serious pests affecting yield and quality of berry crops across Canada. Following systematic assessments, several insect pests of high concern for berry production were identified among those with greatest potential for pesticide risk reduction. Control of these pests has relied mainly on older, broad-spectrum insecticides some of which have undergone regulatory review by Health Canada's Pest Management Regulatory Agency (PMRA). Two products were phased out in 2016 as result of this review, thus growers need alternative solutions to control these pests in their berry crops.

This report summarizes the support being provided through Pesticide Risk Reduction to develop and implement a reduced-risk strategy for managing priority insect pests of berry crops. This strategy work started in winter 2016 and was conducted in collaboration with provincial crop specialists, industry stakeholders, and research scientists. The strategy targets three important berry crops grown in Canada: strawberry, raspberry and highbush blueberry.

Through stakeholder consultations held to-date, the most pressing crop/pest issues were identified, some solutions were discussed and prioritized, and an action plan is being put into place for implementation. Selection of solutions is driven by the goal to achieve viable pest management while reducing risks associated with insecticide use, including development of pest resistance to these products.

Recommended solutions to pursue for filling identified gaps include:

Updating the status of research and management for Spotted Wing Drosophila in Canada;
Integrated management of root weevil and white grub complex in berry crops;
Integrated management of tarnished plant bug and thrips in day neutral strawberries;
Integrated management of cyclamen mite in nursery and field strawberries.

More details about eventual projects addressing these solutions will be included in upcoming iterations of this report as these become available. It is anticipated that adoption of the new management tools resulting from this strategy will enable growers to enhance their integrated pest management practices and promote sensible use of chemical insecticides.

Pest management and pesticide risk reduction issues

This strategy focuses on three berry crops widely grown in Canada: strawberry, raspberry and highbush blueberry. While the importance of lowbush blueberry is recognized, this crop is not included in this strategy because the pest issues and production practices are quite different from other berries targeted here. In Canada, about 16,400 hectares (ha) are cropped to strawberries (3,800 ha), raspberries (2,100 ha) and highbush blueberries (10,500 ha) mainly grown in British Columbia, Ontario, Quebec and the Maritime Provinces (Source: Statistics Canada, CANSIM 2016).

Berries crops are affected by numerous insect pests. Some insects are generalists, attacking various berry species, while some are crop specific. Pesticides are used to protect the quality and yields of berry crops from these pests, especially during outbreaks. While newer products were registered in recent years (for example, spinosad, spinetoram), some have been older products belonging to organophosphate, organochlorine, neonicotinoid and pyrethroid chemistry groups. Several of these older products have been or are under re-evaluation to ensure their safety to human and environmental health in light of current science. As a result, two compounds (diazinon, an organophosphate and endosulfan, an organochlorine) were recently removed from the market. Moreover, repetitive use of fewer remaining insecticides with similar modes of action is a risk factor in the development of insect resistance to these products. Cases of Western flower thrips resistant to spinosad and spinetoram are already reported in some greenhouse crops.

Thus, a need was identified to diversify growers' toolbox with alternative options suitable for sustainable, integrated management of priority berry pests.

Strategy development

Some gaps were previously identified for similar insect pests affecting these crops through preliminary stakeholder consultations held in 2003 and 2005. In response PRR supported several projects which addressed some of these gaps before this strategy work was initiated, for example:

However, the need for broader stakeholder and expert engagement in consultations and a more concerted approach to address these pests across the key berry growing regions became apparent.

Working group consultations

In winter 2016, a working group was established to help PRR develop a plan of action to address these pest issues. The group brought together subject matter experts and stakeholders, including grower organizations, provincial extension and pest management specialists, university researchers, federal scientists, and regulators. Since its inception, the working group has consulted and exchanged information through teleconference calls and emails.

Priority issues and gaps

Through multiple discussions, the working group has identified priority insect pests for the selected berry crops and gaps associated with their management (Table 1). These pests had been regularly treated with older insecticides and the need for alternative control options was critical.

The working group has also recommended some reduced risk solutions to address the identified gaps. Further discussions to advance the potential solutions will continue over the coming years.

Table 1: Summary of gaps associated with identified priority pest/crop issues

Pest	Gaps for Strawberry	Gaps for Raspberry	Gaps for Highbush Blueberry
Spotted wing drosophila (SWD) (Drosophila suzukii)	Selected as the highest priority across the three berry crops. While there have been various projects and activities targeting this pest, an overview of the scope and progress with this work in Canada and elsewhere was deemed necessary to inform decisions about future research needs and development opportunities.	See gaps for strawberry	See gaps for strawberry
Root weevils/white grubs complex (For example black vine weevil, Japanese beetle, June beetle, European chafer, et cetera)	Selected as a priority across the three berry crops. Mainly controlled by using organophosphate or neonicotinoid products which are under re-evaluation, a need was recognised for lower risk replacement options for both adults and larvae management. Various species and growth stages of these pests cause different types of damage in various berries and geographic areas. For instance, both adults and larvae of black vine weevil cause problems in British Columbia region. However, root weevil larvae are a serious sporadic problem on strawberries in Eastern Provinces. Japanese beetle, European Chafer and June beetle are mainly a problem on strawberries and blueberries grown in Eastern Provinces. These are of growing concern due to lack of control solutions.	See gaps for strawberry	See gaps for strawberry
Cyclamen mite (Phytonemus pallidus)	Selected as a priority for nursery and field strawberry. While there is only one insecticide available, it is difficult to effectively control this pest with sprays. Growers need effective sampling techniques, thresholds and various control tools for nursery and field productions.	Not applicable	Not applicable
Tarnished plant bug (Lygus lineolaris)	Selected as a priority for day neutral strawberries. Lower risk products and non-chemical solutions are needed for season-long protection.	Not applicable	Not applicable
Thrips (Frankliniella spp.)	Selected as a priority for day neutral strawberries. There is only one insecticide class available for pest suppression (spinosyns), and it is prone to development of pest resistance. Additional lower risk solutions are needed, including biological controls, to allow rotation of control options.	Not applicable	Not applicable
Raspberry crown borer /Clearwing moth (Pennisetia marginata)	Not applicable	Selected as a priority for raspberry. With the loss of diazinon, which leaves only one insecticide option available, the threat from this pest is expected to rise. A need was identified for educational and outreach materials for growers, for example an information sheet on the pest biology and proven management approaches.	Not applicable
Beetles For example raspberry fruitworm (Byturus tomentosus), red necked cane borer (Agrilus sp.), raspberry cane borer (Oberea bimaculata), clipper weevil (Anthanomus signatus), sap beetles (Stelidota geminata)	Not applicable	Selected as a priority for raspberry. With the loss of diazinon which controlled some of these pests, the threat from these pests is expected to rise. A need was identified for lower risk replacement control options.	Not applicable
Blueberry maggot (Rhagoletis mendax)	Not applicable	Not applicable	Selected as a priority for blueberry in eastern Canada. While several insecticides are available, growers need non-chemical options for sustainable control of this pest.

Action Plan

As a result of above consultations, the following activities were chosen to pursue first starting in 2017:

1. Updating the status of research and management for Spotted Wing Drosophila in Canada

The working group proposed to conduct an overview of outcomes from recently completed and ongoing SWD related projects and activities undertaken in the last 5 years by Canadian researchers and investigators in a format that is easily accessible and useful to the vast majority of interested stakeholders across Canada.

Implementation: A series of four 2-hour webinar sessions was held over winter of 2017 to share information about the regional situation and progress made in SWD management in Canada. This webinar series was organized by the National Spotted-wing Drosophila Technical Working Group (SWD-TWG), a group established in 2012 as the result of a partnership between the Canadian Horticultural Council and AAFC's Pest Management Centre. Highlighting research activities underway provincially, at universities and within Agricultural and Agri-Food Canada (AAFC), these sessions allowed an opportunity to share new information and discuss remaining gaps in knowledge and management technologies. A listing of the speakers and presentation topics during the Spotted Wing Drosophila Canadian Webinar Series is available. The shared information will be helpful in identifying next steps to be undertaken toward robust sustainable solutions to manage SWD.

2. Integrated management of root weevil and white grub complex in berry crops

The working group suggested investigating various approaches such as the use of entomopathogens, biopesticides, novel monitoring, trap crops, ecosystem and habitat enhancement, thresholds, etc., relevant to these pests as part of an integrated pest management (IPM) system.

Implementation: This priority was included in Agriculture and Agri-Food Canada's internal call for proposals in 2017. No proposals were received.

3. Integrated management of Tarnished plant bug and thrips in day neutral strawberries

The working group suggested investigating various approaches such as trap/cover crops, ecosystem and habitat enhancement, biological control, thresholds, or biopesticides, pertaining to these pests as part of an IPM system.

Implementation: This priority was included in AAFC's internal call for proposals in 2017. As a result, a new 2 year project was initiated in spring 2017. The project addresses the integrated management of tarnished plant bug in day-neutral strawberries and is conducted at the AAFC's Saint-Jean-sur-Richelieu Research and Development Centre, Quebec.

4. Integrated management of cyclamen mite in nursery and field strawberries

The working group suggested investigating solution options in the areas of sanitation, improved monitoring, thresholds, biological control, plant-derived insecticidal oils, et cetera, as part of an IPM system.

Implementation: This priority was included in AAFC's internal call for proposals in 2017. No proposals were received.

This report will be updated periodically as new projects are rolled out and new information on results becomes available.