Blog, What's Wrong With My Trees?
What’s wrong with my tree? European pine sawfly
European pine sawfly is the most common sawfly in Missouri
European pine sawflies are defoliating host-specific insects. Common hosts include Ponderosa pine, Lodgepole pine, and other native and ornamental pines. In our region, we see damage to many pine tree species, especially Scotch and mugho pines.
Adults resemble large houseflies, and larvae are greenish caterpillars that lift their heads and tails when disturbed. Females have a 
serrated ovipositor (the organ through with they lay eggs) that they saw slits into needles in which to lay their eggs. Eggs hatch in April through May, and the larvae may feed until mid-June.
Signs and symptoms of European pine sawfly
Overwintering eggs can be found on the needles of pines after a heavy frost when the egg-laying scar turns orange. Other signs and symptoms of European pine sawfly include:
- Defoliation
- Needle browning
- Needle drop
Treatment and management of European pine sawfly
Since European pine sawflies have few natural predators, you can nip this pest in the bud by working with Hansen’s Tree Service. Inspect your trees in late fall through early summer, pick off the larvae, and place them in a bucket of soapy water. If a large population is present, contact the experts at Hansen’s Tree Service about treatment.