Bug Identification

Asked December 22, 2019, 11:06 AM EST

We recently cut a fresh tree at a farm in St. Mary’s County, MD. The tree is infested with a small insect — it does not appear to have wings and is the similar size as a fruit fly. It’s black with 4 white dots on its back, 6 legs. Pics attached. It appears to be sucking the sap from the tree; they are falling off in our house and they are on the floor still alive. What is it and are they invasive? Can I throw them outside or should I kill them? Should I let the tree farm person know? Thank you, Laura

St. Mary's County Maryland

1 Response

Hello Laura,

This appears to be a Giant Conifer Aphid, a common hitchhiker on cut Christmas trees. They do suck sap, but as the cut tree naturally starts to dry out, they can wander off. They won't cause harm in the home, but could leave a stain on carpets or furniture if squished. For now, the best solution is to simply vacuum them up as they appear; for future Christmas trees, a thorough hosing-down with a strong jet of water outside before bringing in to decorate will help dislodge any hitchhikers. (Let the tree drip-dry outside or in a garage before bringing in.) If an outside water spigot is unavailable or turned off for the winter, try giving the tree several strong taps on the ground to knock off any insects clinging to the tree. If the tree farm offers tree-shaking services (where they put the tree on the vibrating place for a few minutes), this too may help knock them off. While the tree farm may already be aware of them, it wouldn't hurt to inform them of what you found. It's possible they opted to control them through means other than insecticide use.

Miri