Hemlock Sawfly – Diprion similis

Hemlock Sawfly – Diprion similis Common Name: Hemlock Sawfly Latin Name: Diprion similis Appearance: The Hemlock Sawfly is a type of sawfly, a group of insects closely related to wasps. The adult sawfly has a black body with yellowish markings on the abdomen and legs. They have two wings and can grow up to 12 mm long. The Hemlock Sawfly’s larvae are greenish-yellow with black markings and can grow up to 25 mm in length. Egg: The eggs of the Hemlock Sawfly are small and black and are laid in clusters on the needles of hemlock trees. Pupa: The Hemlock Sawfly pupae are reddish-brown and formed in a cocoon in the soil. Larva: The Hemlock Sawfly’s larvae are greenish-yellow with black markings and can grow up to 25 mm in length. They have several pairs of legs and are known for their distinctive saw-like appearance, with rows of spines along their bodies. Adults: The adult Hemlock Sawfly has a black body with yellowish markings on the abdomen and legs. They have two wings and can grow up to 12 mm long. Host plant: The Hemlock Sawfly feeds on the needles of hemlock trees. Territory: The Hemlock Sawfly is found throughout North America, primarily in forests where hemlock trees are present. Damages caused by Hemlock Sawfly: The Hemlock Sawfly can cause significant damage to hemlock trees, particularly in large outbreaks. The larvae feed on the tree’s needles, causing defoliation and weakening the tree. In severe cases, the tree may be killed. The Hemlock Sawfly can also impact the forest ecosystem, affecting the growth and survival of other tree species and impacting wildlife that depends on the trees for habitat. Life history and Habits: The Hemlock Sawfly has a one-year life cycle. The adult sawflies emerge in the spring and lay their eggs on the needles of hemlock trees. The eggs hatch in the spring, and the larvae begin feeding on the hands of the trees. The larvae go through several stages of growth, shedding their skins each time before pupating in the soil. The pupae overwinter and emerge as adult sawflies the following spring. Outbreaks of Hemlock Sawfly populations can occur every few years, with the epidemic’s severity varying depending on environmental conditions such as temperature and precipitation. Hemlock Sawflies also exhibit synchronized population outbreaks, where many individuals simultaneously hatch and feed on the trees.