Psyllopsis fraxinicola

There is a new pest of ash trees in Oregon, Psyllopsis fraxinicola. This psyllid is a recent introduction to Oregon. It was first identified in 2008 in Portland. It has since been confirmed from Salem, Sherwood, and Tigard but likely has a greater geographic distribution.

This species of psyllid is reported from the Palearctic region and more recently introduced into North and South America, Australia, and Servia. Host plants include several ash species (Faxinus excelsior, F. angustifolia).

There are two generations per year. Eggs are at the base of the terminal leaf buds, along leaf veins, and on bark. Hatch is likely to occur in late May or early June in Oregon. There are five instars of the nymphs. The first two instars are yellow with red eyes. The third and fourth instars are green. The last instar is green with pink eyes and reddish wing buds. There is not local data yet but adults can be found June through October in Britain.Overwintering eggs are laid near the beginning of August (Jerinic-Prodanovic et al., 2007).

Damage shows up as curling of young leaves. Heavy feeding may result in chlorosis, necrosis, and general decline in the affected tree.

There are reported natural enemies including Anthocoris nemoralis, a predatory bug. The author has noted lady beetle eggs laid near a colony of the psyllid as well. Encyrtid wasps are parasites of this species.

Online Resources:

Bristish Bugs: Psyllopsis fraxinicola

Jerinic-Prodanovic, D. et al. 2007. Psyllopsis fraxinicola Foerster (Homoptera: Psyllidae), a new ash tree pest in Serbia. Pesticidi i fitomedicina. v. 22(1) p. 51-57. [Serbian. Abstract in English]

Noyes, J. and P. Hanson. 1996. Encrytidae (Hymenoptera: Chaldidoidea) of Costa Rica: the genera and species associated with the jumping plant lice (Homoptera: Psylloidea). Bull. Nat. His. Mus. Lond. Ent 65(2):105-164

Original version: <8 June 2011)

Last revision <19 December 2016>

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