Spotting insect pest problems on ornamentals is not always an easy task. LCOs spend much of their time with the turf and an insect invasion may go unnoticed in trees and shrubbery until much damage is already done. The key to effective management is early detection and proper diagnosis of the problem.
Common insect concerns. One of the most invasive species that is currently getting a lot of attention is the Emerald Ash Borer, which has killed tens of millions of ash trees in southeastern Michigan alone but has since also invaded a large portion of the East Coast and Midwestern regions. “The Emerald Ash Borer outbreak has people worried and rightfully so,” says Bruce R. Fraedrich, vice president of research for Bartlett Tree Research Laboratories based in Charlotte. “It was just identified in New Hampshire for the first time and it keeps on moving.”
Following Superstorm Sandy on the East Coast, Fraedrich says that boring species in general have become a problem in regions affected by the storm. “There’s a lot of debris and fallen trees on the ground in areas where they aren’t going to be cleared – such as off of roadways in areas like New York, New Jersey, and Connecticut,” Fraedrich says. “The insects will invade those trees, which will serve as breeding sites, and ultimately move to other trees in the area.”
Down South, Tyler Chandler, ornamental segment manager with WinField Solutions, says that Whiteflies are a huge problem. In Miami, where Chandler is based, these tiny, sap-sucking insects are causing the yellowing or death of leaves.
But often it’s the sticky honeydew that Whiteflies excrete that is the first sign noticed – and the biggest complaint. This sticky goo can drop on cars or the surrounding landscape and even cause a secondary ant infestation.
Hard and soft scale insects are also a problem throughout the country, says Shawn Bernick, vice president, research and development and technical support with Rainbow Treecare Scientific Advancements based in Minnetonka, Minn.
They commonly occur on woody ornamentals causing damage such as yellowing, premature leaf drop, growth restriction and possibly even death. Mites and leafmining insects are also common depending on the region. Of course, these are just a few of the insects that may be encountered in varying parts of the country.
Develop a plan. While the types of insects vary greatly with region, there is some key evidence to search for on any ornamentals, including tattered leaves or flowers, color change, dead plant parts, and of course evidence of the insect itself. The key is to spot these problems early. That means a thorough inspection.
“With insects, contractors need to always be aware of what may be on the horizon,” says Stephanie Darnell, technical development manager, insecticides, of the Environmental Science division of Bayer CropScience. “You have to be ahead of the game – particularly with invasive species.”
From a treatment standpoint, the trends are moving toward systemic applications, Bernick says. “We’re looking more at applications that are applied to the soil or directly to the tree as opposed to spraying,” he says. “While there are still insects that require sprays, we’re setting a lot more systemic treatment.”
Many businesses are also being as proactive as possible in order to prevent some of these problems in the first place.
“We call it plant health care,” says James Zwack, director of technical services for The Davey Tree Expert Co., headquartered in Kent, Ohio. “That would include all the things we can do to keep the tree in great condition and able to defend itself. Then if a problem does arise, we can determine the best way to specifically target it. This whole idea of ‘spray and pray’ – spraying everything and hoping you get the bad stuff, but also killing a lot of good stuff – is something that the industry as a whole is moving away from. And that’s a good thing.”
An overall movement toward softer and greener practices is also an industry-wide trend. Geoff Smith, northeastern sales representative, turf and ornamental, for Gowan USA says that he’s seeing a lot more homes with edible gardens and if the homeowner is looking to harvest those fruits and vegetables, then the LCO needs to be more careful than ever about insecticide selection.
“There are certainly some headwinds around organic chemistries and some new uses and combinations have been really effective,” Smith says. “We had a lot of success with insecticidal soap and azadirachtin mixed in-tank, and the two products are OMRI approved for edibles. There is still a lot of snake oil in the organics market but a few companies are bringing real solutions to the table that offer similar control to synthetic chemistries.”
As LCOs and tree care techs get out to handle these properties, Darnell says it’s important to consider what the customer wants – and expects – from the service they’re providing. While LCOs are often paying closer attention to the turf, ornamentals are a critical part of the landscape, too.
Darnell says they’re also more likely to have sentimental value. “It’s not uncommon for homeowners to have emotional attachment to trees and other ornamentals on their property,” she says. “It helps to be aware of that. A tree may have been planted when a family member was born or those peonies might have been put in by a grandmother. It’s always good advice to recognize the value of these landscape items to your customer as you begin to formulate your treatment plan.”