Pest News for week of May 14th

ORNAMENTALS AND TURF

From: Steve Frank, Extension Entomologist

Cottony Maple Scale Egg Hatch

Cottony maple scale eggs are hatching. For some reason cottony maple scale is the least common cottony scale I find on campus. I seem to find cottony maple leaf scale and cottony camellia scale far more frequently. It also seems to be a little later as I reported on the other cottony scales and sent Twitter alerts (@OrnaPests) a couple weeks ago. However, I did find some cottony maple scale the other day and was able to get a picture. The main diagnostic difference between cottony maple and cottony maple leaf scale is where the ovisacs are produced. Cottony maple scale produces ovisacs on branches, whereas cottony maple leaf scale ovisacs are on leaves. Insecticide recommendations are similar as other soft scale listed at:http://www.ces.ncsu.edu/depts/ent/notes/O&T/shrubs/note156/note156.html.

Be on the Lookout for Emerald Ash Borer 

Emerald ash borer has not yet been found in North Carolina. However, it is found in Tennessee and Virginia so it is just a matter of time before it arrives here (or is detected). The reason I bring it up now is that it is peak adult activity (based on degree day estimates) so they may be more noticeable now than other times of year. Adults will be emerging from D-shaped holes in ash trees. If you notice ash trees that seem to be in decline look for these exit holes and frass around the base of the tree. Early detection of emerald ash borer in North Carolina will be critical in trying to reduce the economic impact and protect trees. The most comprehensive and up-to-date information on emerald ash borer can be found at http://www.emeraldashborer.info/.

Japanese Maple Scale Crawlers

We are approaching peak activity of Japanese maple scale crawlers. Japanese maple scale is an armored scale that has many hosts including maple and many other woody ornamentals. Scales are extremely tiny and are often concealed in bark crevices and branch crotches. However, at high densities entire trunks may be covered. Information provided by University of Maryland indicates there are two generations per year (http://ipmnet.umd.edu/nursery/docs/JapaneseMapleScale-UMD2011.pdf). Japanese maple scale has not been studied in depth in North Carolina but we assume there are two generations here also. Japanese maple scale has been an increasingly important pest in the past decade or so and made its way throughout eastern North America. The most effective pesticides tested have been insect growth regulators such as Distance and Talus. The neonicotinoid including Safari has also been effective. More information is availablehttps://utextension.tennessee.edu/publications/Documents/W277.pdf or complete biology and management information was presented in a recent webinar (http://ecoipm.com/ ipm-webinar/ipm-webinar-archive/).

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