Tuesday, May 28, 2013

Pest Alert for Week of May 27th


From: Steve Frank, Extension Entomologist

Cottony Maple Leaf Scale Eggs

Cottony maple leaf scale is one of several cottony scales in the genus Pulvinaria. 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 Cushion Scale

Cottony cushion scale is an exotic pest that became a very important pest of citrus. However, it is quite generalist and does affect several ornamental plants such as nandina, euonymus, boxwood, rose and others. Cottony cushion scale is very noticeable when female egg sacs are present. They are present now and most of the time there are several overlapping generations per year. Cottony cushion scale is an example of a relatively successful biological control program in the U.S. The vedalia beetle was captured in its homeland of Australia and released to bring the pest under control. Although cottony cushion scale can still be found and remains a pest it is often kept in check by this wide-spread beetle. These are in a different family (Mararodidae) than other soft scales (Coccidae). However, control measures are similar to those outlined in the soft scale management note:

Recommendations for the use of chemicals are included in this publication as a convenience to the reader. The use of brand names and any mention or listing of commercial products or services in this publication does not imply endorsement by North Carolina State University, North Carolina A&T State University or North Carolina Cooperative Extension nor discrimination against similar products or services not mentioned. Individuals who use chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information about usage regulations and examine a current product label before applying any chemical. For assistance, contact an agent of North Carolina Cooperative Extension.

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