Nursery pest roundup

Nursery pest roundup

Use these tips for managing red-headed flea beetle, crape myrtle bark scale and emerald ash borer.

April 25, 2017
Matt McClellan

Red-headed flea beetles are a native pest that feeds on the roots and leaves of many nursery crops. Their eggs overwinter in potting media, and Steven Frank, an associate professor in entomology and plant pathology at North Carolina State University, believes their larvae may overwinter in pots, as well. Read Frank's tips for dealing with this pest here. 

The second year of survey data tracking crape myrtle bark scale has provided researchers information they believe will help mitigate the pest’s effect on trees, said a Texas A&M AgriLife Extension Service expert.

Erfan Vafaie, a AgriLife Extension entomologist and integrated pest management program specialist, and other Texas Extension collaborators in College Station, Huntsville and Dallas, have monitored pest numbers the past two years to help determine crape myrtle bark scale’s seasonal life cycle and peak crawler activity. The data collected has helped researchers develop strategies against them.

The crape myrtle bark scale, an invasive insect species from Asia, secrete a sugary solution, known as honeydew, that subsequently results in black mold along the branches and tree trunk, Vafaie says. The crape myrtle bark scale has not shown to be fatal for plants.

Crape myrtle bark scale on an infested tree in Shreveport, La.
Allen Owings, LSU;

 

But the bark scale do affect the aesthetics for the popular ornamental tree, especially in the Southern U.S., Vafaie says. Observations suggest the crape myrtle bark scale could be responsible for stunted growth in plants as well as reduced flowering.

Two years of data collected by Vafaie and his collaborators show bark scale crawler, or nymph, numbers peak between mid-April and the beginning of May. He suggests two treatment options – contact spray or systemic – for landscapers or growers who have identified signs of crape myrtle bark scale based on data. Read more about their research here.

As emerald ash borer spreads throughout North America, researchers remain optimistic that native and introduced natural enemies will help suppress EAB densities below a damage threshold for the long-term survival and reproduction of EAB-tolerant ash genotypes.

Because the borer is originally from northeast Asia, U.S. and Chinese scientists have been searching for EAB and its natural enemies in that region since 2003. In Asia, EAB population densities are relatively low due to the combined effects of EAB resistance in Asian ash species, scarcity and patchiness of forests, and the EAB natural enemy complex.

Read about the borer's natural predators here.

Top photo, emerald ash borer: David Cappaert, Bugwood.org