DALLAS — Reports of ladybugs gathering in large masses on buildings and in attics is very good news for gardeners fighting aphids, say Texas A&M entomologists in both Dallas and College Station.
“This newly-arrived species, Harmonia axyridis, is a friendly insect that feeds on aphids in roses, crape myrtles and other ornamentals, as well as pecan trees,” said Dr. Allen Knutson, Dallas entomologist with the Texas Agricultural Extension Service. “This is the time of year they gather in a cool, protected place for the winter,” Knutson said. “We’ve had reports throughout the North and Central Texas corridor from the southern tip of Texas and north into Oklahoma.”
“There’s no cause for alarm,” said Bill Ree, Extension entomologist in College Station. “They don’t bite, sting, eat wood or carry disease. In fact, one pecan farmer told me he’d cut a hole in his attic if that would assure they’d stay over and eat aphids in his trees next spring.”
They’ve been sighted in the greatest numbers in Northeast and Central Texas where one county Extension office received more than a hundred calls.
The Harmonias are similar in size to other common ladybugs but distinctive in appearance because of white markings around the eyes that look like goggles. Their color varies from light orange to the familiar deep red and there may be no spots or as many as 18.
“They will hibernate in an attic or other protected place until spring and then depart to feed on aphids,” Knutson said. “Their leaving won’t be nearly as dramatic as their arrival. We believe the benefits in controlling aphids and other insect pests far outweigh any nuisance factor in their overwintering habits.”
Knutson also speculated that their increase is a natural occurrence resulting from the presence of many aphids in pecans this past year. They are moving into areas of Texas where they can find a ready food supply.
“We documented their presence in Texas two years ago, and now we see them reaching a critical mass. We’ve had no reports of people being concerned or scared, just curious about them. And that’s the right response. Their being here is good news.”
To prevent their becoming a nuisance inside the house, Knutson advised caulking cracks and, should they intrude into your home, using a vacuum to remove them.