Aphid Alert: a research/outreach program providing region-wide virus vector surveillance
to
the Northern Great Plains potato industry
Edward B. Radcliffe, radcl001@umn.edu
Aphid
Alert 2002, No. 4,
July 26
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
| Aphid Situation in
Week Ending July 26
Flight activity
of the bird cherry-oat aphid, Rhopalosiphum padi,
increased sharply during the sampling week ending 26 July.
Our data suggests that 2002 will be a year of heavy bird
cherry-oat aphid pressure. Our research implicates
bird cherry cherry oat aphid
and green peach aphid as the two most important vectors of PVY in
our region. The large population pressure of this
species early is not a good omen. As the cereals ripen, bird
cherry-oat aphid flight activity increases. The first green
peach aphid capture of the year occurred at Grand Forks.
Green peach aphid arrived in sizable numbers in southern Minnesota
early in the year, but few can be found on potatoes in the
Northern Great Plains. Cooler temperatures during the past
week may favor green peach aphid increase.
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| Weather Conditions and Late
Blight Cooler weather and high relative humidity prevailed over much of our region this past week. Such conditions are highly favorable for the development of late blight. To date, no potato late blight has been reported in Minnesota, North Dakota or Manitoba. Wisconsin has not been so fortunate. It is vitally important to maintain regular fungicidal protection of the crop because these materials, while effective protectants, can not arrest infection, should it occur. New growth needs to be protected and rain may wash fungicide from the foliage. Potato late blight status reports |
| Subscriber
Alert This is the fourth issue of Aphid Alert 2002. This newsletter is intended to alert seed potato producers in the Northern Great Plains to flight activity by aphid species that are 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 is updated as additional data becomes available. To become an e-mail subscriber, send us an e-mail message with the word "subscribe" in subject line. If you have no interest in receiving this newsletter by e-mail, please reply with the word "unsubscribe" in the subject line. Some e-mail subscribers may not wish to receive messages containing graphics. If so, reply with the the words "no graphics" in the subject line. |
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Minnesota locations: mean aphid captures per
trap during the
week ending July 26 |
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North Dakota locations: mean aphid captures per trap during the week ending July 26
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Manitoba locations: mean aphid captures per trap during week ending July 26 (see Manitoba Agriculture and Food Website)
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Wisconsin, South Dakota and Nebraska locations: mean aphid captures per trap during the week ending July 26
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Figure: Trap locations in the Aphid Alert network in 2002
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Figure: Cumulative captures of green
peach aphid (per trap), 1992-1994, and 1998-2001. Three
distinctly different seasonal patterns of green peach aphid
abundance have been observed. In 1998 and 1999 green peach
aphid were abundant with total captures approximately an order of
magnitude greater (10X) than that of 1992, 1993 and 1994, and two
orders of magnitude greater (100X) than that of 1993 and 2001.
For the Minnesota and North Dakota seed potato industry, low
green peach aphid pressure in 1994 coincided with the end of a
multi-year PVY epidemic and the low green peach aphid pressure of
2001 coincided with the end of a multi-year epidemic of PLRV.
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Figure: Cumulative captures of
bird cherry-oat aphid (per trap), 1992-1994, and 1998-2001.
This aphid comes off wheat and other cereals. The species is
typically abundant in the Northern Great Plains. In
our area, green peach aphid and bird cherry-oat aphid appear to be
the two most important vectors of PVY. Lowest abundance of
bird cherry-oat aphid during the years the Aphid Alert network has
operated was in 1994, which coupled with low green peach aphid pressure, coincided with the end of a multi-year epidemic of PVY.
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Ted Radcliffe Last modified: Friday, July 26, 2002 © Regents of the University of Minnesota, 2002
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