Many
thousands of Multicoloured Asian Lady Beetles, Harmonia axyridis,
were reported in Windsor and LaSalle during October 2000 and again
in October 2001. Swarms of the brightly coloured beetles landed on
the sides of homes and disappeared into siding cracks. This
introduced beetle was first found in Ontario in 1994 but is now one
of the most commonly seen "ladybugs" in our region. This species
which is also called the Southern Lady Beetle has been spreading
rapidly since its introduction into the United States. In September
2001 another introduced species, the Seven-spotted Lady Beetle,
Coccinella septempunctata, was also reported in large numbers.
Other species of lady beetles are also known to aggregate in
sheltered spots where they hibernate for the winter. Homeowners
should not be concerned as the beetles will disperse on their own
next spring.
INTRODUCED
SPECIES
Over 100
years ago the citris orchards of California were saved from an
infestation of scale insects by the importation of an Australian
lady beetle. Since that time many species of lady beetles have been
introduced into North America for the control of aphids and other
insect pests. Unfortunately some of our native species have
declined with the increase of these exotic species. The three most
common introduced species in Windsor are Multicoloured Asian,
Seven-spotted and Russian Wheat-aphid Lady beetles.
