If your pine tree is suddenly infested with a black-headed, Medusa-like worm, fear not — chances are the tree is simply hosting a colony of European Pine Sawfly larvae.

Sawfly larvae hatch in March or April and feed on the outer cells of pine needles. They prefer scotch, red or mugo pines, but will happily settle for most any two- or three-needled pine. They do not like Eastern cedars or blue spruces. Feeding in large groups, the larvae take turns arching their heads and tails away from the needle to ward away predators.

European pine sawfly larvae

This unpredictable but seemingly orchestrated movement gives them an eerie macabre quality. Identifying and treating an infestation is relatively easy.

Step 1: Ward off infestation by keeping trees well-watered, especially during dry spells. Maintain healthy soil conditions through proper use of soil amendments and fertilization.

Step 2: Sawflies earn their name because they look like flies, even though they are not, and because the females lay their eggs in slits, which they cut into pine needles with their saw-like ovipositor. After the first frost, rows of yellow ovals will appear along the edges of infected pine needles where sawfly eggs have been laid. Pull off infected needles and dispose of them. Do not compost them or leave them on the ground.

Step 3: Larvae are easily identified once they have hatched. Young larvae are olive green and 1/4-inch long, with black heads. They grow to about 1 inch in length, developing green and yellow stripes along the way. Small infestations can be controlled by clipping off colonized branches and disposing of the branches and larvae in sealed plastic bags.

Step 4: Sawfly larvae make good chicken feed. Larvae can be knocked to the ground by shaking the branches or using a high-pressure water hose. Chickens may need some encouraging at first, but should take to eating the tasty treats in no time.

Step 5: If left untreated, larvae activity will cause severe defoliation of pine trees. Affected pine needles will turn brown, wither and eventually drop to the ground. Treat heavy infestations with one of several over-the-counter treatments. When used as directed by the manufacturer, Spinosad, Carbaryl (Sevin), Neem Oil, Insecticidal Soap and Pyrethrins are all effective for eradicating sawfly larvae. Bacillus thuringiensis (Bt) will not work on sawfly larvae. Sawflies are not caterpillars; they are related to ants, bees and wasps.

— Have a home improvement question for the Fix-It Chick? Email it to Linda Cottin at features@ljworld.com.