Colonization of soybean aphid, Aphis glycines (Homoptera:
Sternorrhyncha: Aphididae) is of concern to soybean growers in
Minnesota. An objective of this study was to determine when
aphids were first detected in soybean at a statewide level by
taking random samples during the growing season from all
counties where soybean is grown. From these samples, we
hypothesized that spatial data might provide indirect evidence
of where soybean aphid successfully overwintered. In addition,
we might understand when distribution from soybean to soybean
might occur by examining the proportion of alatoid nymphs in the
samples. In 2002, soybean aphids were first detected in late
June in the lower third of the state. But by early July, soybean
aphids were found evenly dispersed in Minnesota. Since apterae
were collected in the June samples, the data suggest that
soybean aphid successful overwintered throughout much of
Minnesota in 2001-2002. Peak abundance of alatoid nymphs was
11-17 August, indicating summer migrations are hig