Alliums Insects Pest Management

Dry Bulb Onion Growers Receive Emergency Use Registration for Thrips

J. Chaput, Minor Use Coordinator, OMAFRA

The Pest Management Regulatory Agency (PMRA) recently announced the approval of an emergency use registration for DELEGATE WG Insecticide (spinetoram) for control of onion thrips on dry bulb onions in Nova Scotia, Quebec, Ontario, Manitoba and Alberta.  Delegate WG Insecticide was already labeled in Canada for control of several insect pests on a range of crops.  Furthermore a complete minor use submission is under review to seek eventual, full registration of DELEGATE for thrips control on dry bulb onions in Canada.

Onion thrips, Thrips tabaci (Lindeman) are a pest of onions around the world.  In Canada, it is considered a key pest wherever onions are grown and the number one pest of onions in most provinces.   Various life stages of onion thrips actively feed on onion leaves, reducing photosynthesis, reducing plant vigor and yield, and vector and transmit Iris Yellow Spot Virus (IYSV).

In the US, onion thrips were ranked as the number one pest requiring urgent attention due to lack of effective solutions at the 2005 U.S. IR-4 Food Use workshop.  Rapid resistance development to all available, registered materials has become widespread in North America and around the world.  Delegate WG Insecticide was identified as a viable solution to help manage onion thrips.  There have been no new products registered in Canadafor onion thrips management in several years and control failures continue to increase.

The emergency use registration of Delegate WG will help in the interim to manage resistant thrips populations; however management of onion thrips will require a comprehensive IPM and resistance management program with access to all available tools and strategies.  The following is provided as general information only.  Users should consult the complete label before using Delegate WG.

DELEGATE WG Insecticide can be used for control of onion thrips in dry bulb onions in Ontario, Quebec, Nova Scotia, Manitoba and Alberta until October 31st, 2011 only.  Delegate WG can be applied at a rate of 200 – 336 grams product per hectare in 300 – 500 litres of water per hectare.  A maximum of 3 applications per year is permitted at a 7 – 10 day interval.   A 3 day pre-harvest interval is permitted.

Follow all other directions for use on the DELEGATE WG Insecticide label carefully.

DELEGATE WG Insecticide should be used in an IPM program and in rotation with other management strategies to adequately manage resistance.

We wish to thank the personnel of Ministère Agriculture, Pêcheries et Alimentation du Quebec, Manitoba Agriculture, Alberta Agriculture and Nova Scotia Agriculture for their input, support and assistance.   We also wish to thank the personnel of the Ontario Ministry of the Environment, Alberta Environment, Quebec Environment, Manitoba Conservation, Nova Scotia Environment and Dow AgroSciences Canada Inc. for their support of this registration and the personnel of the Pest Management Regulatory Agency for evaluating and approving this important pest management tool.  Special thanks are expressed to the Conseil québécois de l’horticulture, Fresh Vegetable Growers of Ontario and other grower associations who helped to cover the submission fees for this emergency use registration.

For copies of the emergency use label contact Marion Paibomesai, OMAFRA, Guelph(519) 826-4963, Jim Chaput, OMAFRA, Guelph (519) 826-3539 or visit Dow AgroSciences Canada Inc. website at

1 comment on “Dry Bulb Onion Growers Receive Emergency Use Registration for Thrips

  1. Hello Marion Paibomesai,
    We have a company called Nieveen & Bouma Agro Weather Service and we are specialized in producing/developing decision support systems and warning systems.
    In the third week of March we are visiting the Michigan state university in Lansing, to give a couple of workshops.
    Is it an idea that we come to Ontario, to discuss and see if we can join some work together?

    Thanks in advance!

    Best regards, Erno Bouma
    Dronten, The Netherlands

Leave a Reply

%d bloggers like this: