Overwintering eggs that have been deposited in the needles can be easily located after a heavy frost turns the egg-laying scar yellow. The European pine sawfly (Neodiprion sertifer) is found in large numbers and "waves" in mass as a means of scaring off predators. The insect spends the winter as eggs deposited in pine needles. European pine sawfly larvae are gray-green with black heads, there is a dark gray stripe along each side of the body (see a short video of the larvae here). Sawfly larvae look like small caterpillars. Instead of a stinger, the female has a sawlike ovipositor that she uses to make a slit in the edge of a needle. She deposits a single egg into each slit and several eggs in a needle.The larvae are caterpillar-like with six or more pairs of prolegs on the abdomen. (See "Pine Sawfly – Species" for a detailed description of larvae.) The larvae feed primarily on white pine and other five-needle pines, The white pine sawfly (Neodiprion pinetum) larva is cream color with four rows of black spots on the body and a black head. Moth and butterfly caterpillars have five or fewer prolegs. You’ll often find them crawling around on leaves, especially on the edge. This sawfly larva feeds for about six weeks. Life Cycle - European Pine Sawfly They can feed on many pines including Scotch, Eastern white, and Austrian. Adult pine sawfly (Diprion pini) are 10mm long brown winged insects, The larvae reach up to 25mm long and are pale green in colour with a brown head and black markings. Sawfly larvae have the curious habit of raising their heads and tails in a threatening manner when disturbed. Fox-coloured sawfly (Neodiprion sertifer) is 7-9mm long and pale orange-brown. It feeds on mugo pines as well as many other pines. They are related to and resemble bees in size and shape. The larvae of sawflies are superficially similar in appearance to moth caterpillars. Adult pine sawflies are seldom seen. The sawfly larvae may be confused with caterpillar and moth larvae, as they all look like worms crawling around on the leaves and stems of plants. They feed on older mature leaves, leaving the emerging needle alone. It feeds primarily on white pine, but can be found on red, pitch, and mugo pines. They have two pairs of transparent wings but are not capable of stinging. They are worm-like and crawl around like worms and have many different patterns.