It’s hard to believe 2017 is here. Each year, we find ourselves challenged by a new, different, or even existing pest in our landscape. To help you prepare for the new year, Swingle is sharing their annual pest predictions so you know what to look for in 2017.
We predicted that Emerald ash borer would be found outside of Boulder by June 2016. That prediction came true with the discovery in Longmont on June 6, 2016. Though not proven, it is suspected that the infestation came from some transported wood, which contained the borer. This infestation in Longmont is still within the quarantine area in Boulder, which demonstrates how the insect will move and become established. The responsible method of dealing with ash wood is to take it to an approved disposal site where the material will be buried. We know as more trees are removed and more infested ash wood is moved, these detections will become more common.
We saw a dramatic increase in the numbers and varieties of scale insects in 2016. Oyster shell scale has not been overly aggressive for 20 years, yet is becoming more prevalent in the north part of the state. Usually a pest of aspen, oyster shell is back to infesting ash trees and lilac shrubs as well. Willow scale continues to be found in the southern part of our service area on aspen trees. This is a very prolific insect and devastating to aspens. European fruit lecanium scale has been around for many years and usually doesn’t cause damage. However, in 2016 we saw lecanium becoming aggressive on oak and maple trees. We expect this insect to spread rapidly in 2017. European elm scale has been an issue on American elm for over a half a century in northeastern Colorado. Elm scale has been a consistent problem for longer than any other landscape pest in Colorado. 2017 should be no different.
Japanese beetle is a strong flier – spreading on its own by up to 2 miles per year. Most of the Denver metro area is active with Japanese beetle. Prolific populations exist in Boulder, Longmont and Greeley – the beetle is just getting started in Fort Collins. Feeding from the adults on a wide variety of plants is very noticeable. However, we are seeing more larvae (grub) feeding on turf grass roots. For 2017 we are expecting more lawn damage from the beetle larvae.
We’ve been battling these pests for the past several years throughout the front range. This insect persists on Austrian pine for much of the year and can be found in the winter months. With a relatively mild winter thus far, were expecting the aphid infestations to increase in the early spring.
Weather patterns over the past six months favor a resurgence of Ips engraver beetle infestations in blue spruce. This insect causes the death of its host. Once the beetles attack, there is no way to save the tree.
When we think of mites, we equate them with warmer weather. Lawn mites are cool season pests that do their damage during the winter and early spring months before the lawns green up for the season. A very warm, dry fall certainly gives the mites an early start. The predicted normal precipitation, combined with warmer than expected temperatures, will create drought conditions early in 2017 – favoring early spring mite infestations.
Yes, dutch elm disease is still around and there is a risk to American elms as well. But the disease incidence has been very low for the past 13 years and we don’t expect to see a resurgence in 2017. Mountain pine beetle is a recurring insect. Pine beetle populations are on the decline. Swingle expects to see only spotty activity from this insect in the next several years.
Keep these pest predictions in mind to help ensure you will have a healthy green landscape in 2017.