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JUNE 7, 2012 | WWW.PRODUCER.COM | THE WESTERN PRODUCER
PRODUCTION
RESEARCH | PESTS
RESEARCH | CUTWORMS
Scientists study crop-killing cutworms
Growers can contribute
Prairie project | Researchers collaborate on three-year, $525,000 project
BY BARB GLEN LETHBRIDGE BUREAU
BY BARB GLEN LETHBRIDGE BUREAU
The makers of the movie Alien could easily have been inspired by the sight of parasitic wasps emerging from the body of a cutworm. As wasp life begins, the cutworm dies. The scenario is playing out in laboratories at Agriculture Canada’s Lethbridge Research Centre, as well as in fields across Canada. It is a welcome sight for farmers with crops damaged by some of the many cutworm species on the Prairies. The acts in the lab are part of a three-year research project to better identify cutworm species and their natural enemies and provide farmers with tools to identify and combat them. The $525,000 project, funded by the Canola Agronomic Research Program (CARP), is headed by Lethbridge-based research scientist Kevin Floate, but its tentacles reach into all prairie provinces. Researchers from the universities of Alberta, Manitoba and Lethbridge are involved, as are government entomologists from the three prairie provinces, Agriculture Canada staff in Beaverlodge, Alta., Lacombe, Alta., and Saskatoon, Alberta Agriculture staff in Lacombe, researchers at Lethbridge College, Canola Council of Canada staff and prairie farmers. “It’s quite a large project,” said Floate as he observed work in the research centre lab May 25. However, the research team is also large and will build on work done by others, notably research scientist Bob Byers, now retired but also contributing to the project. Cutworms are a major economic issue for agriculture because of their variety, life cycles and appetites for almost anything green. “We like to think of it as a pest complex because you can’t point at one target and come up with a magic bullet. It’s a moving target and it keeps changing shape,” said Floate. He describes the cutworm project as having four main objectives: • develop tools to better identify the many different cutworm species. Floate said there are seven or eight species of particular interest to farmers, among them the dingy, ar my, redbacked, glassy, darksided, pale western and bertha • obtain more information on the biology of cutworms. Some species are the same colour and some worms of the same species can be different colours. Some feed above ground and some below. Various species attack crops at different times in the growing season. Tools are needed to better identify the species and ways to control them • obtain more information on natural enemies to cutworms, such as parasitic wasps. Floate said wasps can control cutworm outbreaks but can’t be relied upon for good control. There are many species of paras i t i c w a s p s, s o m e o f w h i c h haven’t been identified and
Vince Hervet holds a dish of southern army worms, one of the cutworm species being studied. Project Cutworm is a three-year, $525,000 research study designed to learn more about cutworm identification, biology, parasites and control options. | BARB GLEN PHOTOS
Parasitic wasp larvae emerge from the body of a cutworm. The wasp larvae look like additional legs on the worm but have just burst through the worm’s skin. Once out, the larvae will build cocoons from which wasps will emerge.
BOB BYERS
KEVIN FLOATE
RESEARCHER
RESEARCHER
named. Research at the U of M is focused on parasitic wasp identification as part of the project • develop extension tools for producers, including photographs and charts for accurate identifi-
cation of species and potential control measures. “I think it’s entirely feasible to come up with a kit to identify cutworms,” said Floate. He envisions online photographs and charts to help producers identify the species, as
well as service labs that could also provide quick and accurate species identification Not all cutworm species are crop pests, but there are two types of pests: those that overwinter and those that blow in as moths. The latter species doesn’t commonly overwinter in Canada. Floate said cutworm outbreaks tend to be cyclical, and the Prairies are now in the middle of a cycle. Cutworms have already been reported this spring, although the extent of early damage is still unknown. “In terms of why the outbreaks are sporadic, it can depend on weather patterns in the United States for those pests that come up from the U.S. or it could depend on how cold the winters have been,” said Floate. Weather, temperature, moisture conditions and soil tilth are additional factors. Cutworms can go through several generations during the growing season, depending on the species, which creates an even greater control challenge. As well, many species can feed on the same crop, and the same species may feed on different crops. Some species feed in the day and some at night. “In some cases, you’ll have a cutworm but no crop. In a stubble field, they’ll start feeding on weeds,” said Floate. “It’s a challenge.”
Cutworms are already active in crops on parts of the Prairies and growers are urged to scout for the pests to limit damage. While they’re at it, they can also assist with a three-year cutworm research project now underway. A research team stretching across Western Canada is working on cutworm identification, parasitic wasp identification and cutworm biology. Samples are being collected that will contribute to a database designed to evolve and expand as more information becomes available. The study, funded by the Canola Council of Canada and led by Kevin Floate of Agriculture Canada in Lethbridge, is a result of grower demand for more information on cutworms and their control. “I’m pretty optimistic that we can better prepare producers with options for control,” said Floate. Specific cutworm trouble spots this season are being monitored and can be found in Alberta through the Prairie Pest Monitoring Network at www. agric.gov.ab.ca/app68/listings/cutworm/cutworm_map.jsp. Information is also available through the canola council. Researchers need samples from Alberta, Saskatchewan and Manitoba to assist with the ongoing cutworm project. In Alberta, some researchers are available to collect samples if farmers call to report an outbreak. Farmers can also mail or drop off larvae samples. In Saskatchewan and Manitoba, samples can be dropped off or mailed. Specific procedures are required to identify the sample and preserve the cutworm so it is not damaged in transit.
STEPS FOR COLLECTING Troy Prosofsky of the canola council provided sample collection guidelines: • handle the worm (larva) as little as possible • do not include soil with the specimen • place one larva plus feeding material (part of a host plant) into a clean container suitable for shipping. Paper bags will work for those who drop off samples • every larva must have collection data including collection date, collector’s name and e-mail or phone number, nearest town, GPS or legal land description if known, specimen description (species, if known), name of host plant and previous crop