European Pine Sawfly (Neodiprion sertifer)

Description

An adult European pine sawfly looks like a wasp due to having a broad waist and membranous wings. They are about 0.2-0.33 inches long, though the females are larger than the males. Females are reddish-brown with saw-tooth antennae, while males are black with feathery antennae.

Other Common Names: Pine sawfly, red pine sawfly

Distribution: Native: Europe; Invasive: North America

Habitat: Christmas tree farms,landscapes, and ornamental nurseries

Do they sting: No

Lifespan: 7-9 days

Predator: Ants, beetle larvae, birds, deer mice, fly larvae, frogs, lizards, predatory wasps, shrews, etc

Behavior and Characteristics

Feeding

The larvae feed on the needles of several pine trees, including Jack pine, Japanese pine, red pine, and Scots pine.

Defensive

If threatened, the larvae may raise the front and end portions of their bodies and regurgitate a chemical developed by consuming pine needles.

Life Cycle

European sawflies mate in the fall, with females laying fertilized eggs between September and October.

1. Egg Stage

The females make a slit into the pine needle with the help of their ovipositors. They will then individually lay between 100 and 120 eggs through the slit.

A European pine sawfly egg has a translucent white coloration, oval shape, and smooth and shiny texture. Each egg is about 0.083 inches long and 0.025 inches wide.

2. Larva Stage

After 2-3 weeks, the eggs hatch, and larvae emerge. An individual larva is initially white with a brown head capsule. As they mature, the body becomes yellowish-green, and the head becomes reddish. Black spots also develop in 4-8 rows along their bodies.

A full-grown larva is about an inch long and has three pairs of thoracic legs and 6-7 pairs of prolegs.

3. Pupa Stage

Pupation occurs inside a reddish-brown paper cocoon that looks like a cylinder with rounded ends. They remain in this stage during winter and emerge in the fall of the following year.

Getting Rid of Them

While this species is considered a pest due to the damage done to pine needles and possibly stunting the growth of a tree, it is rarely enough to harm the tree permanently. Oviposited pine needles can be easily distinguished due to the patchiness and subsequently removed. Spraying with pesticides or introducing beetle larvae may also work as a form of control.