Pine Sawyers vs. Asian Longhorned Beetle
An Asian longhorned beetle and whitespotted pine sawyer
It’s almost Memorial Day weekend, and to a lot of folks, that means barbecues, picnics, and spending time with family and friends (with proper social distancing, of course). But to those of us who work at the Massachusetts Forest Pest Outreach Program, Memorial Day means the emergence of the whitespotted pine sawyers. Some of you may already be familiar with this Asian longhorned beetle look-alike. For those who aren’t, the whitespotted pine sawyer is a harmless native insect, and no cause for alarm.
If you find a suspicious insect while exploring the outdoors, here are four ways to distinguish a whitespotted pine sawyer from ALB:
- Whitespotted pine sawyers start to emerge in late May, and are active through August. ALB does not begin to emerge from trees until July.
- Sawyer beetles target dead and dying pine trees and other conifers, while ALB attacks living hardwood trees, especially maple. In fact, you often find sawyers near stands of pine.
- Sawyers are a dark bronzish-black color with a rough texture to their wing cases, while ALB is black and very shiny, like patent leather.
- Whitespotted pine sawyers have a distinct white half-circle shape between their wing covers, just behind the head (see red arrow). This part of the wing case is called the “scutellum.” On Asian longhorned beetle, the scutellum is black and hard to distinguish from the rest of the wing casing.
So if you see a large black beetle with long antennae this month, you can be reasonably certain it is not Asian longhorned beetle, because it’s too early in the spring. However, if you review the list above and still are not sure, you can report it here. Be sure to get photos or capture the specimen if you can.