Volume 1 Issue
7
July 2, 2004
Minnesota Crop Pest Report
SOYBEAN APHIDS FOUND IN SW MINNESOTA
 Bruce
Potter, IPM Specialist SW MN, reports that small colonies of soybean
aphids were observed in Cottonwood and Brown Counties in Minnesota.
There have also been reports that soybean aphids have been found in
IA, IN, IL, PA, and NY.
GRASSHOPPERS IN MARGINS
 Surveyors
found one grasshopper hot spot this week in Benton County where 71
grasshoppers / 10 sweeps were found (Figure 1). Statewide,
grasshopper numbers appear to have leveled off as most overwintered
grasshoppers have likely emerged by now. However, grasshoppers may
become more noticeable over the summer as they grow larger and more
mobile.
DISEASES IN WHEAT AND BARLEY
 The
MDA found high incidences of leaf rust on wheat throughout the WC
during the past week (Figure 2). Leaf rust has also been very
prevalent on wheat in southern Minnesota in previous weeks.
A number of other diseases were; found in wheat and barley during
the past week. Tan spot / Septoria is very prevalent on wheat
throughout western Minnesota. Loose smut, aster yellows / barley
yellow dwarf, covered smut and bacterial stripe were found to be
present in scattered wheat and barley fields throughout the state.
Aster leafhoppers, which vector aster yellows, have been
relatively uncommon throughout much of Minnesota in 2004. However,
higher numbers of leafhoppers were found this week in southern
Minnesota (Figure 7 on following page).
INSECTS IN ALFALFA
 Pea
aphids were common in most stands sampled this week, but not at high
levels. Cowpea aphid was found this week in two fields in the SE. In
2003 cowpea aphid was found throughout the southern half of the
state in MDA surveys.
Potato leafhoppers were only found at economic levels in a few
stands this week. However, three of the four affected stands were in
Houston County (SE). Peak numbers of potato leafhopper are typically
seen during July.
Alfalfa plant bug was also found in greatest abundance in the SE
this week (Figure 3). Plant bugs can compound the injury caused by
high numbers of potato leafhopper.
The information and maps have been made available courtesy Mark
Abrahamson of the Minnesota Department of Agriculture. To access the
entire Minnesota Pest Report newsletter go to:
http://www.mda.state.mn.us/pestsurvey/pestreports/pestreport.html
|
