Spring moves on at a seemingly glacial pace, yet the slowly increasing growing degree days do favor the development and surge of the insect communities. Temperatures have been unseasonably cool for this time of year in much of the northeast, and while actual rainfall has not amounted to much, dampness persists. While this sort of weather progress slows plant development it also allows for an extended blooming period. Daffodils, magnolias, cherries, PJM rhodies, phlox, serviceberry, willows, Pieris, pears, Norway maple, red maple, silver maple and pachysandra continue to bloom and tulips are beginning to break. However, leaf development appears arrested. Soil remains saturated due to the cool dampness, and lawns are greening up with some weeds breaking through.
Unfortunately, the cold wet spring has not completely hindered pest populations. Closed buds and slow leaf out had kept caterpillars from pupating for some time, but even the slow bud break allows the loopers to emerge.
- Wintermoth caterpillars prefer certain tree or plant species but on your landscape it may seem that they are generalist feeders. Early evaluation and treatment , with supplemental treatments during the season will yield the best results.
- Increasing temperatures will bring out fall cankerworm caterpillars very soon. These populations will be mixed with wintermoth and hard to differentiate.
- Forest tent caterpillar eggs are due to hatch over the next couple of weeks, they are most commonly found on oaks but can be generalist feeders; they have also been showing up in smaller and smaller population sizes but have your arborist keep an eye out.
- Eastern tent caterpillars, most commonly found on apple and cherry species, should hatch in the upcoming week or two, recently these populations have decreased. However, eastern tent caterpillars can be injurious defoliators, as so should be monitored closely.
- The azalea sawfly caterpillars will pupate soon, they appear pale green and nearly indistinguishable from their primary host’s foliage. When the weather and temperatures are right large populations of sawflies can completely defoliate shrubbery. They are difficult to identify and monitor due to coloration and feeding patterns, make inspection part of your regularly scheduled maintenance performed by your plant healthcare specialist.
- Hemlock wooly adelgid (HWA) is still active, although low temperatures have kept population size in check. HWA stresses trees out season after season, evaluate trees in need of possible treatments. Consider kelping or fertilizing trees showing signs of stress.
- Spruce spidermites are already highly active on spruces, firs, hemlocks and arborvitae. All trees of these genera should be evaluated and monitored throughout the season and treated as needed.
- Viburnum leaf beetle eggs usually hatch soon after buds of the host plant open. Dead terminal shoots and rough stems are symptomatic of an infestation. Prune away dead shoots and dispose of them by burying or burning in order to truly rid your landscape of these pests.
- Black legged ticks or deer ticks have been active for a couple of weeks already. Protect yourself, your family and your pets by using the appropriate repellents and treatments. Wear long sleeves and pants when outside and check yourself when you return indoors.
Treatments need to occur at the times when they will be most effective, of course, sometimes the weather prohibits the ability or effectiveness of products. Your arborist and plant healthcare technician will schedule applications and monitoring as suited to your landscape’s needs, expected leaf out, insect life cycles and ideal weather. Because weather patterns are not one hundred percent predictable and pest problems are not an exact science, plant healthcare has to be flexible and adaptive, be assured they are doing their very best to get and maintain the optimal results for your landscape.