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Red pine needle midge

Defoliation of the current year's needles of pole size Norway pine near Lake George in Hubbard County was attributed to the red pine needle midge, Thecodiplosis piniresinosae. This is the first report of red pine needle midge in Region 1 that we are aware of. These insects prefer trees that are slow growing with low vigor and are open grown. Growth loss can last up to four years. In May and June, the tiny maggots feed at the base of new pine needles hollowing out the base of the needles as the shoots are developing. The needle's response to the feeding is to bend or droop downward around the shoot or twig. Look for a bulbous swelling at the needle base. Needles will be hollowed out for approximately 1/4 inch from the swelling and needles are easily pulled out of their sheaths. Adults emerge from late May through mid-June. Soon after emerging, females lay eggs at the base of new needles. Larvae hatch within a week, bore into the new needles and hollow out the needle base as they feed causing the needles to weaken. Larvae leave the needles in the fall when the needles begin to turn brown. Larvae drop to the ground inside the needle and over-winter as larva in the soil. A tiny wasp parasite Tetrastichus generates the best control, parasitizing as much as 90% of the population. Chemical control is not recommended for this pest.