Aphid Alert: a research/outreach program providing region-wide virus vector surveillance
to
the Northern Great Plains potato industry.
Aphid
Alert 2003, No. 5,
July 18
Published cooperatively by
the
Department of Entomology,
College of Agricultural, Food & Environmental
Sciences,
University of Minnesota, the
University of Minnesota Extension
Service,
and the State Seed Potato Programs of Minnesota and North Dakota
Project funding
provided by:
the Northern Plains Potato Growers Association,
the Minnesota State Legislature,
Rapid Agricultural Response Initiative
&
the
United States Department of Agriculture,
Cooperative State Research,
Education and Extension Service,
Integrated Pest Management Program, North Central Region
WWW address:
http://ipmworld.umn.edu/alert.htm
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Potato insect update for the Northern Great Plains, week ending
July 18 Aphid flight activity throughout the Northern Great Plains continued to be light during the last week. Bird cherry-oat aphid captures declined from the previous week, but again this was the species most abundantly represented in our trap captures. Soybean aphid populations are building rapidly on soybean throughout Minnesota and the Red River Valley. This aphid can reach very high densities on soybean and has a great propensity to produce winged adults when crowded. Previous experience suggests that soybean aphid tends to be underrepresented in our trap captures. Soybean aphid does not colonize potato, but we have shown that it can acquire and transmit PVY. Buckthorn aphid continues to be commonly represented in the trap captures from Manitoba. In Minnesota and North Dakota, potato aphid was captured at most locations and is a common colonizer on potato throughout the region. Only one green peach aphid was captured during the past week. Potato leafhopper continues to be the insect pest of greatest immediate concern to Northern Great Plains potato growers. Some growers have reported potato leafhopper pressure above the economic threshold even after the application of foliar insecticides. Potato leafhopper management is discussed in Aphid Alert No. 3, July 3. Colorado potato beetle remains
a control concern for some growers, particularly in more northerly
locations. In southern and central Minnesota the first
summer generation of larvae have finished feeding and most
have entered the soil to pupate. The summer adults have not
yet emerged. Results from the 2003 University of Minnesota
insecticide efficacy trials targeting Colorado potato beetle are
summarized in the following tables. Three experiments were
conducted, 1) Systemic insecticides applied at planting or
hilling, 2) Systemic insecticides applied at planting but
with varying seed piece row spacing, 3)
Foliar insecticides
applied when late instar (3rd and 4th) larvae first appear. |
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 Expt. 2. Systemic insecticides applied at planting but with varying seed piece row spacing |
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 Expt. 3. Foliar insecticides applied when late instar (3rd and 4th) larvae first appear |
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Minnesota-North Dakota aphid data, week ending July 7
Manitoba aphid data, week ending July 10
Information on the aphid situation in Manitoba can also be found at www.gov.mb.ca/agriculture/crops/insects/index.html, and the Manitoba Agriculture and Food potato hotline at 1-800-428-6866. |
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Late Blight Situation High relative humidity and locally heavy rainfall drove up Late Blight disease severity values across much of the Northern Great Plains during the past several days. Highest severity values are reported in U.S. counties on either side of the Red River of the North and in the Carman/Morden/Winkler region of Manitoba. Most locations have reached the threshold where Late Blight fungicides should be applied on a routine schedule. Spray intervals should be shortened in periods of rapid increase in disease severity value accumulation. The only confirmed case of Late Blight to date has been from Carberry, Manitoba (July 10).
Potato late blight status reports |
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Subscriber Alert This is the fifth issue of Aphid Alert for the 2003 growing season. This newsletter is intended to alert seed potato producers in the Northern Great Plains to flight activity by aphid species known to be potential vectors of potato viruses. We report results weekly on the WWW, by e-mail to subscribers, and by surface mail to all Minnesota and North Dakota seed potato growers. The hard copy and e-mail versions of Aphid Alert report aphid capture data available as of the date they are mailed. The WWW version will be updated as additional data becomes available. To become an e-mail subscriber to Aphid Alert 2003, send us an e-mail message with the word "subscribe" in subject line. Note that current subscribers need not resubscribe. If you have no interest in receiving this newsletter by e-mail, please reply with the word "unsubscribe" in the subject line. |
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Ted Radcliffe Last modified: Friday, July 18, 2003 © Regents of the University of Minnesota, 2003
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