Features Chemicals Insects
Coragen approved for swede midge in cole crops

May 21,
2010, Mississauga, Ont – Growers in Ontario have access to a new tool to help
protect cole crops from swede midge, thanks to a new minor use registration for
DuPont Coragen insecticide. 

May 21,
2010, Mississauga, Ont – Growers in Ontario have access to a new tool to help
protect cole crops from swede midge, thanks to a new minor use registration for
DuPont Coragen insecticide. 

Swede midge,
a pest that can damage brassicaceae crops, was first identified in Ontario in
2000.

“This
insect can be a real challenge to manage,” said Hannah Fraser, provincial
entomologist for horticulture crops at the Ontario Ministry of Agriculture,
Food and Rural Affairs (OMAFRA). “Research conducted by Dr. Rebecca Hallett at
the University of Guelph indicates that they can have four to five overlapping
generations over the growing season.”

Coragen
will fit into an Integrated Resistance Management (IRM) system because it is
powered by the active ingredient Rynaxypyr, which comes from a
whole new class of chemistry – Group 28, the diamides.

The tiny,
light-brown adult swede midge is hard to differentiate from other midges; and
the larvae are even harder to scout. According to OMAFRA, swede midge larvae
are initially 0.3 mm long and transparent, typically feeding in groups near the
growing point. According to Fraser, damage from swede midge can be confused
with other common problems in crucifer crops; therefore, when swede midge first
showed up in Ontario, it was not immediately recognized.  

Low
levels of damage can rapidly become a large problem if the population is left
unmanaged. Without a good Integrated Pest Management (IPM) program that
involves regular monitoring, growers could lose the entire crop to swede midge.

“Growers
must follow OMAFRA guidelines, monitor each field and spray early,” says Saghir
Alam, development specialist with DuPont Canada. “Swede midge is not like other
pests, such as cabbage looper or diamondback moth, where if you miss spraying
one instar you can get them when they’re bigger. In this case, it’s very
difficult to see the pest and by the time you see damage, it’s too late.”

OMAFRA
recommends using commercially available pheromone lures and white Jackson-style
traps to help track the emergence and activity patterns of the pest, as well as
to determine the need and timing of insecticide sprays.

More
information about Coragen is available at www.coragen.ca.