With spring comes a much-awaited opportunity for the beautification of condo  green spaces, many of which may have been neglected throughout the colder  months. Yet the arrival of warm weather also heralds the arrival of pesky  insects and other plant pests that may impede a manager’s landscaping plans.  

 Fortunately for condo management, experts say many native New England plant pests are easily controlled. “A lot of times you’ll find that pests that are native to a geographic area never, or very rarely, cause significant problems,” says arborist Don Parrott, a board member of the Connecticut Tree Protective  Association, “because if it evolved in a certain area, plants that are there also evolved with  different checks and balances which keep that pest under control.”  

 Coccoidea

 Among native pests that do require a manager’s attention, New England’s wide variety of scale insects (Coccoidea) are perhaps the most common offenders. The parasitic pests quickly attach themselves to plant leaves, secreting a  waxy, scale-like coating that makes them resistant to many pesticides.  

 These immobilized insects draw nourishment from sap flowing throughout the plant’s vascular system, causing eventual death to the host. Despite resistance to many common pesticides, scales can often be treated with simplehorticultural oils or insecticidal soap.

 Leaf Miners

 Leaf miners, such as New England’s native birch leafminer (Fenusa pusilla), will first be seen throughout the region’s trees in May, their appearance followingquickly on the heels of developing foliage.

 Easily recognized by the distinctive, curving paths they create on the leaves of their hosts, first generation leaf miner infestations can cause complete  defoliation of a property’s trees in less than a season. From there, subsequent generations will often lead to weakeningand death of the host plant. If found early, leaf miners are controllable with  organic insecticides sprayed directly on the leaves of an affected tree.  

 Bronze Birch Borer

 Another native pest, the bronze birchborer (Agrilus anxius) is a common wood-boring beetle found throughout much of  North America and is particularly prevalent in the Northeast. Though the borer  can prove deadly to any birch tree on a condo property, New England’s white-barked Canoe Birches are most susceptible.  

 While the BBB is treatable with insecticides – sometimes requiring as many as three treatments a year – property managers should take care to plant only native white birch trees whenlandscaping plans call for these white-barked beauties. The often-seen Asian and  European variants, frequently sold in American nurseries, show even less  resistance to the borer’s attack.  

 Aphids

 Aphids (Aphididae), another native New England parasite, feed on small plants  and shrubs in much the same way as scale insects, and, in addition to their  parasitic feeding habits, these small, pear-shaped pests often carry deadly plant viruses. In fact, one recentstudy shows aphids to be responsible for approximately 50% of all plant virus  transmissions.  

 Noticeable effects of an aphid infestation on a property’s plants and shrubs may range from yellow, brown, or curling leaves to wilting and death. Upon  discovery, these dual-threat insects should receive rapid attention. Fortunately for condo managers, most aphids are readily controllable with traditional chemical treatments, and some even respond to “greener” methodssuch as biological insecticides or the introduction of predator insects.  

 Eastern Tent Caterpillar

 Another common New England pest, the eastern tent caterpillar (Malacosoma  americanum) is most recognized by the white, billowy masses it creates in the  crooks of apple and other fruit trees. ETC infestations are often easily  remedied, though the insects rarely cause serious damage to a property’s trees. Should management choose to take action, condo groundskeepers can  usually clip the larval egg sacs and the caterpillar’s cottony tents from fruit trees and other ornamentals, then simply burn the  offending branches.  

 Condominium managers should take care not to confuse the eastern tent  caterpillar with the similar-looking but far more destructive gypsy moth  caterpillar, which, Parrott says, despite common misconception is not a New  England native. “Most of us think of it as a native New England pest,” he explains. “But actually they’re not native pests, they’re a pest that was introduced. I think some scientist was trying to make silk or something and so he imported these  caterpillars from Asia, had them in his laboratory busily making silk, and they  escaped into our environment and became a pest.”  

 Hemlock Wooly Adelgid

 But gypsy moths are hardly the only Asian visitors to plague New England  properties in recent decades. “In Connecticut,” notes Parrott, “one of the big pests is hemlock wooly adelgid (Adelges tsugae). It’s a relatively new insect…and it’s just totally wiping out all of the native hemlock trees.”  

 A particularly pervasive pest, the HWA has spread throughout New England since  its introduction from Asia and has, in fact, blanketed much of the East Coast.  Yet the insect has proven particularly destructive in New England, where the  ubiquitous hemlock has long been such a familiar fixture. “It’s a very tiny sucking insect – sucks sap from the twigs of the trees. And it may take ten years or so, but once the infestation develops on a tree, in about ten years it will kill them,” says Parrott. “But in a residential setting – you know, a managed property like a condominium property – with the righttreatment you can keep them alive.”

 Asian Longhorned Beetle

 Another Asian émigré, the Asian longhorned beetle (Anoplophora glabripennis) was first discovered in  the New York area in the mid-1990s, and has since begun spreading throughout New England, proving one of the most destructive insects to plague the region in modern memory. Easily recognized by its black-and-white-banded antennae and blue leg colorings – “a very striking beetle,” notes Rhonda Santos of the USDA’s Animal Plant Health Inspection service – the ALB has become the target of serious government action in recent years. “A cross-section of an ALB-infested tree is going to look like Swiss cheese because of the  tunneling galleries from the larvae feeding within,” Santos explains. “Treesthat it attacks are essentially being eaten from the inside out, so it’s kind of sad if you’re a tree lover.”  

 And saddest of all for property managers, some of whom may have spent decades  cultivating stands of ornamentals, the discovery of Asian longhorned beetles at  a condo is frequently an automatic death sentence for a property’s trees. “The federal government is trying to manage the onslaught of the insect. So it’s really taking it almost like an armed battle,” says Parrott. “If they find it, they just move in. When the feds get in there, they will just quarantine a certain area – dictate that it might be a half mile radius, for instance. They’ll go in with government contracts, cut every tree [and] grind it up so that any insects  inside that wood are completely destroyed. By doing it that way, they’retrying to manage the spread of it.”

 Emerald Ash Borer

 Yet despite the growing media attention focused on ALB, surprisingly, another Asian pest has proven far more destructive. “Emerald ash borer (Agrilus planipennis or Agrilus marcopoli) is not at all on the same scale. It’s like a thousand-fold worse,” Parrott remarks. “One of the big problems with it is that it moves very easily on its own. The  Asian long-horned beetle is what we’d consider, from an insect perspective, a very poor flyer…. The emerald ash borer, on the other hand, is a very good flyer.  

 “The feds [seem to] have decided it’s impossible to really very effectively contain it.” And while the slow-moving ALB has progressed through only a few New England  states during its 15-year U.S. visit, the emerald ash borer has spread  throughout fourteen states and parts of Canada in less than a decade. “I think they’re giving up ontrying to contain it,” Parrott notes. Unlike the Asian long-horned beetle, however, EAB attacks can be  treated without sacrificing a property’s entire tree population. “If it gets into an area, if we have individual specimen trees, we can treat them  and keep them alive,” says Parrott. “But that would be individual specimens, you know, like on a residential  property.”  

 When insect problems do arise, university extension offices can frequently  provide answers to a board member’s questions. “A lot of times folks might send a picture in and say ‘I’ve got this tree’ or ‘I’ve got these spots on these leaves,’” explains Donna Ellis, senior extension educator for the University of Connecticut’s Plant Science Department. “There are [extension] offices where master gardeners work. There are faculty members and staff  members and people like myself who could help identify something and then make  recommendations.”  

 In addition, “most states would have arborist associations,” says Parrott, “so [property managers and condo boards] could consult with their state arborist association and that should be able to  point you to some qualified capable arborists. Similarly, they should have  statewide nursery contractor associations. Your property managers will get some  overlap.”  

 Experts like Parrott are careful to caution that managing a property’s insect pests is a year-round activity. It begins in spring, but does not end  with the onset of cold weather. “In the winter,” Parrott notes, “property managers need to be dialed in more to review what happened last year, what got away from us, and what were some of the issues that we seemed to be behind the eight ball on.” And when a new pest problem does arrive, it will likely be a part of board members’ lives for years to come. “You have to treat it ongoing. It may take a treatment, just one application or  something, every three years. But you must keep that up, whatever your issue  is,” says Parrott. “It may not be that you need to spend money or do something everyyear, but you need have a program in place that is followed and you can usually  keep the trees that you want.”  

 Exercise Restraint

 Most importantly, says Ellis, managers should exercise restraint in pest control, perhaps saving themselves dollars and headaches in the process. “I think I would just welcome and encourage condominium owners and those who are  maintaining the grounds to... take things in stride and realize that a plant, to be healthy, doesn’t have to be 100% free of holes or spots. It’s good that we do have some tolerance. Sometimes it’sokay for plants to have some damage if they’ve got beneficial insects or caterpillars or beautiful butterflies,” says Ellis.  

 “I think it’s good for us to exercise some tolerance and accept the fact that plants can  have some degree of damage to them and they’ll still be fine.”  

 Matthew Worley is a freelance writer and­­­ a frequent contributor to New England Condominium magazine.