Do you think you see a lot of ladybugs? No wonder, there are nearly 5,000 kinds worldwide, and 400 of those species can be found in North America.
Ladybugs come in many colors and patterns with red, yellow and orange wing covers and spots numbering from 15 to none. They are generally about a quarter of an inch long and have oval bodies, with the female larger than the male. The wings are transparent. The beetle can smell with sensors on its feet, and uses its antennae to touch and taste.
The adult ladybug lays about 300 eggs, making sure to choose a spot where aphids are numerous. The eggs hatch in two to five days and the newly hatched larvae feed on aphids for about 21 days before pupating. The pupa takes about a week to develop into an adult. The spots do not develop for 24 hours and so a plain bug that you see probably is brand new.
The adult can have a life span up to 3 years in ideal conditions and can lay up to 1,000 eggs in her lifetime.
In 1999, four ladybugs were sent into space as part of an experiment. Appropriately named Paul, John, Ringo and George, they were monitored carefully to observe prey/predator relationships in the absence of gravity. Everything worked as on earth, as the ladybugs survived and the aphids disappeared in the time-honored way.
This appetite for aphids is their chief benefit to the gardener. It is possible to purchase quantities of ladybugs from some garden centers or over the Internet. Of course, there is no guarantee that they will stay around.
Less popular with homeowners are the Asian Multi-colored Ladybugs that have appeared in this country over the past 25 years or so. It is thought that they were accidentally brought in on an Asian freighter berthed in New Orleans. Previously the USDA had imported some as a biological control agent, but that variety proved unable to overwinter.
These imported visitors eat aphids and scale insects as do their American cousins, but they also have the unwelcome habit of home invasion. When temperatures begin to drop in the fall, they seek shelter similar to their original habitats in Japan and often mistake house walls for their native cliffs and are apt to wiggle into crevices around windows and doors for winter warmth.
It is difficult to tell the bad bugs from the good. The Asians are slightly larger, but are still yellow to red and may have up to 18 spots. They do bite, and exude a foul-smelling defensive chemical which may leave a stain on a wall. For most people this is simply an annoyance, but it can be dangerous to those with severe allergies.
There is no good prevention from ladybug invasions that I have found, except being sure that all entries to the house are sealed. Using insecticides inside the house may leave dead beetles that become food for carpet beetles and so lead to more troubles.
It seems to me that we need revenge for these invasions of illegal insect immigrants! How about gift-wrapping a package of Japanese beetles, Gypsy moths and Emerald Ash Borers and sending them back to some address is Asia? Although, as an immigrant myself I suppose we should temper justice with mercy.
Janet Del Turco is a local gardener and a graduate of the Ohio State University Master Gardener program. Contact her at firstname.lastname@example.org.