North Carolina Pest News – September 6, 2013 (Ornamentals & Turf)

— Written By Amie Newsome and last updated by Nikki Davis

NORTH  CAROLINA  PEST  NEWS
Volume 28, Number 22, September 6, 2013

CAUTION: The information and recommendations in this newsletter are applicable to North Carolina and may not apply in other areas.

ORNAMENTALS AND TURF

From: Steve Frank, Extension Entomologist

Yellownecked Caterpillars

Adult yellownecked caterpillars, Datana minstra, occur in June or July and lay eggs on deciduous shrubs and trees. They will feed on many fruit and ornamental trees including birch, elm, oak, maple, Prunus spp. and others. They feed gregariously in late summer. They consume entire leaves except large mid-veins and can rapidly defoliate trees or cause significant damage. I found the caterpillars (pictured) on a bush in the forest. I could not identify the bush because every leaf was gone. Scouting for small caterpillars can help reduce damage and improve control if it is needed. Caterpillar management information is available at: https://www.ces.ncsu.edu/depts/ent/notes/O&T/shrubs/note07/note07.html. See more caterpillars on my blog: http://ecoipm.org/.

Redheaded Pine Sawfly

I found these larvae at the arboretum last year, but have not visited the arboretum to check this year. The redheaded pine sawfly, Neodiprion lecontei, is a pest of pines in ornamental landscapes, nurseries and plantations. Adults emerge in spring and a second generation occurs in midsummer. Eggs are laid on many 2 and 3 needled pine species such as Jack pine, loblolly pine and red pine. Sawflies are not flies and the larvae do not turn into butterflies. They are non-stinging herbivorous wasps. They can defoliate trees and bushes in the landscape. Since they are gregarious, it is sometimes possible to prune an infested branch and remove all the larvae. Management for sawflies is similar to caterpillars, though not all the insecticides will work, so check the label. Horticultural oil is a good bet especially for small larvae. Formulations that contain azadirachtin or spinosad are also effective. For sawflies and caterpillars, management of full grown caterpillars is generally not warranted. The damage is already done and they are hard to kill.

Scales on Liriope

At least six species of scales can be found on liriope. Usually, they do not cause extensive damage. Whatever building in which you are reading this article probably has liriope planted outside and that liriope probably has scale. You never would have known. However, plants in stressful environments or nurseries may be more susceptible to infestations that could degrade plant aesthetics. The armored scales most common on liriope are hard to distinguish, but cause small yellow spots where they feed. Often they are at the base of leaves out of site of you and predators.