Chemical Management of Swede Midge

Monitoring and Scouting
Do not assume that you have an established population of swede midge on your farm, but be on the look-out for signs and symptoms, particularly if you are located within an infested county. Early detection of swede midge is key to maintaining pest populations at manageable levels. Familiarize yourself with the information provided in the section on this website resources.

Insecticides and Spray Timing
Well-established thresholds have not been determined for swede midge. Preliminary research results from Ontario, Canada indicate that growers may have opportunities to optimize their spray applications for swede midge by monitoring pest pressure with pheromone traps.
Growers with swede midge populations capable of causing economic damage are advised to initiate a pest control program incorporating both cultural and chemical management. Transplants should be protected as soon as they are removed from the greenhouse, or immediately after planting. Management of early swede midge populations will reduce the potential for a population explosion by the end of the season.

Once plants are in the field, monitoring swede midge population with pheromone traps and timing insecticide sprays are the keys to achieve satisfactory control of swede midge. In a greenhouse study conducted at Cornell, Assail 30SG provided very effective control of swede midge on cauliflower plants as foliar spray regardless of plant sizes (if coverage was good) and swede midge densities (related to population pressure). However, Assail 30SG provided only up to 9 days of control, after which time, control decreased significantly. When swede midge pressure is high, susceptible crucifer crops need to be protected at all times.

In greenhouse trials conducted at Cornell in 2005, most pyrethroid, carbamate and organophosphate insecticides that are commonly used to control caterpillar pests in crucifers were toxic to swede midge. However, in field situations where swede midge are protected from direct contact with insecticides, many of these materials provide minimal control. No materials that meet organic standards provided effective control of swede midge in laboratory trials.

Based on laboratory and field studies, Cornell was able to provide data to New York regulators to have several products labeled in New York State (link to the page of insecticides). However, check the label before any applications. In areas where swede midge is known to be present and abundant, the safest strategy would be the use of imidacloprid soon after transplanting to provide an estimated 3-5 weeks of control, followed up by foliar sprays of another insecticide.

Insecticides should be wisely used in conjunction with accurate swede midge population monitoring tools to ensure optimal control. However, with very high populations, insecticides will not be able to prevent injury. With a limited tool-kit, the development of resistance to the available insecticides is a serious concern. Choose and use products wisely. Research teams in New York and Ontario, Canada are working collaboratively towards the evaluation and registration of additional insecticides for use in both the field and greenhouse. Check with your Cooperative Extension Service for registration updates. Read labels carefully!

List of Insecticides Labeled for Control of Swede Midge in New York

Updated 3/1/2010

Federal Labels

Assail 30SG (EPA No. 8033-36-82695, a.i. acetamiprid) – rate: 4 oz per acre for control of swede midge in broccoli, gai lon, rapini, Brussels sprouts, cabbage, bok choy, gai choy, caralo broccoli, cauliflower, collards, kale, kohlrabi, mizuna, mustard greens and rape greens. REI: 12 hours, PHI: 7 days. Do not make more than 4 applications per season. Do not apply more than once every 7 days.

Assail 70WP (EPA No. 8033-23-82695, a.i. acetamiprid) – rate 1.7 oz for control of swede midge in the same crucifers as listed on the Assail 30SG formulation above. Do not exceed 8.5 oz per season.2ee recommendations (added unlabeled pest when pesticide is already labeled on crop) labeled in New York only

Admire Pro Systemic Protectant (EPA No. 264-827, a.i. imidacloprid) – rate: 4.4 to 10.5 fl oz per acre for control of swede midge in cabbage, cauliflower, broccoli, Brussels sprouts and radish. PHI: 21 days, REI: 12 hours. Note: as of January 31, 2010, generic versions of imidacloprid (soil applications) are not labeled for swede midge.

Lorsban 75WG (EPA. No. 62719-301-10163, a.i. chlorpyrifos) – rate: 0.67 to 1.33 lb per acre for control of swede midge in broccoli, Brussels sprouts, cabbage, cauliflower, collard, kale and kohlrabi. PHI: 21 days, REI: 24 hours, 3 days for cauliflower. Do not make a second application of chlorpyrifos within 10 days of the first application. Note: as of January 31, 2010, generic versions of chlorpyrifos are not labeled for swede midge.

Provado 1.6 Flowable Insecticide (EPA No. 264-763, a.i. imidacloprid) – rate: 3.8 fl ox per acre for control of swede midge and onion thrips in cabbage, cauliflower, broccoli and Brussels sprouts. PHI: 7 days, REI: 12 hours. Minimal interval between applications: 5 days. Maximum allowed per season: 19.2 fl oz per acre. Note: as of January 31, 2010, generic versions of imidacloprid (foliar sprays) are not labeled for swede midge.

Warrior Insecticide with Zeon Technology (EPA No. 100-1112, a.i. lambda-cyhalothrin) – rate: 2.56 – 3.84 oz per acre for control of swede midge in cabbage, cauliflower, broccoli and Brussels sprouts. PHI: 1 day, REI: 24 hours. Note: as of January 31, 2010, generic versions of lambda-cyhalothrin are not labeled for swede midge.