NATCHEZ — A contagious parasite is attacking crape myrtle trees in downtown Natchez, and local experts are recommending preventative treatment.

Mississippi State University Extension Service instructor David Carter said the infestation is called crape myrtle bark scale. Small white insects cover the affected plants and create black soot that covers the tree and any plants beneath it.

“They’re very easy to identify,” Carter said. “It looks like the whole tree is covered in white and below, just black.”

The parasites usually don’t kill the crape myrtle, but render it so ugly many affected trees have to be removed, Carter said.

The bugs seem to only target crape myrtle trees, which are found on many downtown Natchez streets.

“We’re catching it very early here, and that’s why we’re trying to get the word out to everybody,” he said. “Most of downtown is clean right now, but we certainly want to prevent it (from spreading).”

The insects have been found on crape myrtles on the bluff and on Commerce Street, but can be easily carried across town.

“It’s something that had to be brought in, it can’t just show up,” Carter said. “If a bird lands on one of the trees, and then lands in another tree, then bam.”

Carter is unsure when the insects were introduced to Natchez.

Trees can be treated with any brand of product containing Imidacloprid, a specifically targeted pesticide, to prevent an infection.

The product is poured at the base of the crape myrtle and is absorbed by the roots. The plant’s vascular system carries the product throughout the bark covering the entire body of the tree.

“When insects try to bite the tree, it’ll kill them and they can’t cause any damage,” Carter said.

Pesticide sprays may cause even greater problem because they can kill the parasite’s natural predator, ladybugs.

“As of right now, we’re getting help from ladybugs as a biological control,” Carter said.

The Louisiana State University Agricultural Center suggests scrubbing the tree with soapy water to temporarily remove an existing infestation.