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A Puslinch Diary October 2001 Invasion of the Ladybugs By Brigitte Dimock We have been invaded this fall by ladybugs. There are hundreds of them swarming in the afternoon sunshine, just waiting for an opportunity to get into the house. So I thought it would be interesting to find out a little more about these colorful insects. The picture below shows them trying to get in the screened-in-porch. 
The Ladybug or Ladybird Beetle which we are seeing this year is the Asian Lady Beetle. It was brought in to Canada from the United States about five years ago to help control aphids on soybeans. Due to the long hot dry summer, there were a lot of aphids this year and hence the overabundance of ladybugs. Ladybugs pose no threat to humans; however, because there are so many of them this year, they have started to exhibit some peculiar behaviors: one of these is biting.Adult ladybugs are slightly elongated in shape and can range from 4 – 7 mm in length with black spots on red forewings. Beetles may have a full complement of 13 spots or they may have only a few. Ladybugs are considered "beneficial insects" because they are natural enemies to agricultural pests. Adults and larvae prey mainly on aphids found on crops and flowers. If aphids are scarce, they may feed on small insect larvae, insect eggs and mites. These beetles adjust their life cycle according to the availability of aphids. Females may lay from 200 to more than 1,000 eggs over a one to three month period starting in spring or early summer. The female beetle lays eggs only where she knows aphids are present. Eggs are usually deposited near prey such as aphids, often in small clusters in protected sites on leaves and stems. 
One to two generations occur each year, depending on the length of the season, before the adults enter winter hibernation, usually in a protected site. Development from egg to adult may take only two to three weeks and adults live for weeks or months, depending on the location, availability of prey, and time of year.As a defense, ladybug adults will fall to the ground and "play dead". They also can secrete an amber bad tasting fluid from the joints in their legs. There is no need to worry about the ladybugs that get into your home reproducing. The beetles do not reproduce indoors because there is no food available. In the spring, they will move back outdoors in the search of prey. Any that get in your house can be picked up gently and released outside or, if you have a lot, you can vacuum them up with a small vacuum and then empty the vacuum outside immediately. Remember these are beneficial insects that keep us from having to use too many insecticides. Read previous Puslinch Diaries:Jan, 2001--Municipal Election Day in Ontario.Feb, 2001--An opossum comes to visit. April, 2001--At the Puslinch Library. June, 2001--Puslinch from the Air. October, 2001--Puslinch Invaded by Ladybugs. |