Most likely, the European wood wasp (Sirex noctilio) arrived in the United States inside crating and associated cargo shipping materials. It has been found in New York state. In its native range it is a minor pest, but in countries where it has been accidentally introduced, it has become a serious pest of many species of pines.
European wood wasps attack living pine trees, an they prefer stressed trees. Female wasps insert eggs into the tree trunk. At the same time, they inject a symbiotic fungus and toxic mucus, which act together to kill the tree. The immature wasps develop inside the tree and feed on the fungus as they tunnel through the wood. Foliage on an infested tree wilts, changes from dark green to light green to yellow, and finally to red. Pines of all varieties, including ornamentals, can be attacked.
Visit the European Wood Wasp entry in our online field guide for description, size, life cycle, etc.
It is unlikely that European wood wasps have reached Missouri. However, they can hitch rides on firewood and nursery stock so it pays to keep a watchful eye. If you think you’ve found European wood wasps in Missouri, collect a sample by trapping the insect in a zippered plastic bag. Place the bag in the freezer for several days to kill the insect then mail the sample in a sturdy container (35mm film canisters or empty pill bottles work well) to one of the addresses below. Be sure to include your contact information and the date and location where you captured the sample.
Forest Entomologist, Missouri Department of Conservation
1110 S. College Ave.
Columbia, MO 65201
State Entomologist, Missouri Department of Agriculture
P.O. Box 630, 1616 Missouri Blvd.
Jefferson City, MO 65102