Second Peak of San Jose Scale Activity Expected

Web AdminUncategorized

By Clint Thompson

Peach producers should be wary of a second peak of San Jose scale crawler activity, according to Brett Blaauw, assistant professor at the University of Georgia (UGA) College of Agricultural and Environmental Sciences.

“With the weather starting to come back to whatever normal is and cool down a little bit, I think that will allow the development of the scale insects to pick back up. That could lead to another peak of activity,” Blaauw said.

San Jose Scale
UGA Extension photo shows San Jose scale crawler.

The insect pest has been quiet this year, due to the high temperatures that have scorched the Southeast this summer. But temperatures have cooled some over the past week, which would aid in activity picking up.

Brett Blaauw

In the UGA Peach Blog, Blaauw cautions producers who have a history of San Jose scale issues or have observed problems this season to implement management tactics. Devastation could occur if appropriate action is not taken.

“They are one of the nastier of the pests because they attack the tree itself as well as the fruit. On the tree, they will feed … you can get hundreds of thousands of these tiny little things sucking the sap out of the tree. It can eventually weaken the tree and kill branches,” he said. “I’ve seen pretty much whole trees go down because there’s so much scale on there. They start to lose their leaves and can’t photosynthesize and it just crashes.

“The second problem is when populations build up, they start to move to the fruit. On the fruit, you can get maybe a couple of dozen, even 100 on the fruit, and they speckle the fruit. It makes it look like it has measles. It’s really only a cosmetic issue. The fruit is fine to eat, but it’s definitely something that doesn’t look like anything you’d want to eat. It really reduces the marketability of that fruit.”

A third peak of activity is expected in early August.

Click here for management options.