European pine sawfly

A new pest in the Willamette Valley, European pine sawfly, Neodipiron sertifer, is a pest of pines. The sawfly larvae feed in a gregarious manner, dining through an impressive amount of needles. Detected in the Albany area of Oregon, I've learned damage has been spotted as far south as Cottage Grove.

Larvae have black heads and are light-to-dark gray with light and dark stripes. They have fleshy prolegs without any of the hooked crochets that are found on true legs of caterpillars.

This species of sawflies has one generation per year. It overwinters as eggs, that were laid within slits in needles in the fall. One sawfly female will lay several eggs in each needle in a cluster of needles (Hoover and Barr 2002). Eggs hatch in the late spring, April or May (sightings of N. sertifer larvae coincided with full bloom of black locust in 2018 in the Willamette Valley). They feed gregariously on older needles. Mature larvae drop to the ground in late May and June, eventually pupating in a brown cocoon in August. Adult sawflies emerge in September (Hoover and Barr 2002).

Management targets early feeding activity. Cultural control includes hand picking, use of forceful jets of water to dislodge the larvae, or pruning off infested limbs, if possible without aesthetic damage. Pheromone traps are used for monitoring. Chemical control is aimed at the young larvae. Although the sawfly larvae resemble caterpillars, they are not susceptible to the Bt or Bacillus thuringiensis subsp. kurstaki products. There may be promise to manage this pest with mating disruption (Östrand et al, 1999).

Resources:

Cloyd, R. 2017. European pine sawfly. Kansas State University. April, 2017 <20 June 2018> Nice images, chemical control info.

Hoover, G. and N. Barr. 2002. European pine sawfly. Penn State Extension. <1 May 2018> Very thorough with lots of information.

Östrand, F., Wedding, R., Erling, J., and O. Anderbrant. 1999.Effect of mating disruption on the reproductive behavior in the European pine sawfly, Neodiprion sertifer (Hymenoptera: Diprionidae). Journal of Insect Behavior. March 1999. Vol. 12, Issue 2,

Original publication: 5/1/2018
Most recent update. 6/20/2018

Author: R.L. Rosetta, Extension Nursery Integrated Pest Management, Department of Horticulture, Oregon State University

European pine sawfly damage

European pine sawfly damage

European pine sawfly larvae

European pine sawfly larvae

European pine sawfly larvae

European pine sawfly larvae

European pine sawfly damage

European pine sawfly damage

European pine sawfly damage

European pine sawfly damage

Jumping spider with European pine sawfly larvae

Jumping spider with European pine sawfly larvae

European pine sawfly larvae

European pine sawfly larvae