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Development
of Canola and Rapeseed Resistant to the Cabbage Seedpod Weevil
We completed the second of a two-year collaborative study with Dr.
Jack Brown, funded by the Pacific Northwest Canola Association,
to develop canola and rapeseed cultivars that are resistant to the
cabbage seedpod weevil. To date, we know that condiment mustard
species are totally resistant to the weevil, while all canola and
rapeseed species are very susceptible. Drs. Jack and Angela Brown
have developed crosses between the mustard and canola/rapeseed species;
thus, the question was whether the crosses gained the resistance
of the parent mustard. Studies last year suggested that the crosses
were susceptible. Further analysis indicated that the pod of the
cross was very similar to a canola species, but the seed was that
of a mustard. Because the weevil tastes the pod before she lays
an egg, the weevil may have thought the cross to be a canola/rapeseed-type
pod. We are currently testing the opposite situation where the pod
is that of a mustard species, but the seed is that of a canola species.
The hypothesis is that the mustard pod will either deter the weevil
from laying an egg or that she does not recognize the mustard pod
as a proper host.
Biological
Control of the Cabbage Seedpod Weevil
While surveying for parasites attacking the cabbage seedpod weevil
in commercial canola and rapeseed fields in Northern Idaho, we found
a parasite that attacks adult weevils. Taxonomists identified this
parasite as Microctonus melanopus. Interestingly, this parasite
is not native to the U. S., but in Europe. Our finding represent
the first report of this parasitic wasp in North America and it
may be an important tool for the management of the weevil that attacks
canola and rapeseed in our region.
For more information contact:
Joseph
P. McCaffrey
Phone: 208-885-7548
Fax: 208-885-7760
E-mail: jmccaffre@uidaho.edu
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