Pest Alert for Week of May 26th

ORNAMENTALS AND TURF

From: Steve Frank, Extension Entomologist

New Pest: Daylily Leafminer Active Now

The daylily leafminer is a recent pest from Asia. It was first detected in 2006, but is now spread through much of the Southeast including North Carolina. I spotted some last week on a trip to Georgia. This fly lays its eggs in daylilies and the larvae produce relatively straight, vertical mines. Pruning infested leaves will help prevent the larvae from maturing and infesting new leaves. We are conducting efficacy tests on this pest right now so I should have recommendations for next year. But for now materials targeting other leafminers such could help. A recent article about this pest is in American Nurseryman (http://www.amerinursery.com/article-7705.aspx).

Daylily leafminer damage. Photo: S. D. Frank.

Cottony Maple Leaf Scale Eggs

Cottony maple leaf scale is one of several cottony scales in the genus Pulvinaria. Last week we mentioned cottony camellia scale. You can find these now on their most common hosts maple and dogwood. Stand under a tree and look up and you will see cottony masses about the size of a cotton swap stuck to the bottom of leaves. These are the egg masses. They each contain many hundred eggs that are hatching as we speak. The crawlers will settle and feed on the leaves all summer then migrate back to branches in fall before leaf-drop.

Cottony maple leaf scale ovisacs on a maple leaf. Photo: S. D. Frank.

Midge with an Eye on Maples

The ocellate gall midge, Acericecis ocellaris, causes an ocellate (single-spotted), pale green to yellow, often bright red-margined gall. Galls are 5 to 6 mm in diameter and occur primarily on foliage of red maples, but also A. saccharinum, A. spicatum, and A. pennsylvanicum. I found galls this week on trees in central Georgia so if you have not seen it here yet you will soon. Galls typically appear in May and contain a single, translucent midge larva. Larvae exit the gall and drop to the ground to overwinter as pupae. These are actually quite attractive critters that could even improve the appearance of trees. Just think if someone bred a tree with yellow and red eye-shaped dots it would be all the rage. That said, these midges usually only occur a few at a time and will not harm tree health. Find out more about maple pests in a free e-book:http://ecoipm.com/extension/extension-resources/.

Ocellate galls on a red maple. Photo: S. D. Frank.

For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.