Mountain Ash Sawfly – Pristophora geniculate

Mountain ash Sawfly– Pristophora geniculate Common Name: Mountain-ash Sawfly Latin Name: Pristophora geniculate Appearance: The adult sawfly is black and yellow and is about 6-7 mm long. The wingspan of the sawfly is about 10 mm. The larvae are green with a black head and a black stripe along their back.

• Egg:The eggs of the Mountain-ash Sawfly are small, oval-shaped, and are usually laid in groups on the underside of the leaves of host plants.
• Pupae:The pupae are brown and are found in the soil.
• Larva:The larvae of the Mountain-ash Sawfly are green with a black head and a black stripe along their back. They can reach up to 25 mm in length.
• Adults:The adults of the Mountain-ash Sawfly are black and yellow and are about 6-7 mm long.

Host plants: The Mountain-ash Sawfly feeds on the leaves of various mountain ash trees, including European Mountain Ash (Sorbus aucuparia) and American Mountain Ash (Sorbus americana). Territory: The Mountain-ash Sawfly is found throughout much of North America. Damages caused by Mountain-ash Sawfly: The larvae of the Mountain-ash Sawfly can cause significant defoliation of host trees, leading to reduced growth and vitality. Heavy infestations can also lead to the complete defoliation of trees. Life history and Habits: The Mountain-ash Sawfly has one generation per year. The adults emerge in late May to early June and mate soon after. The females then lay their eggs on the underside of the leaves of host plants. The eggs hatch in about ten days, and the larvae feed on the leaves. The larvae go through several instars before pupating in the soil in late July to early August. The adults emerge from the pupae the following spring.