WSU Tree Fruit Research & Extension Center

Pear Entomology

Friday, November 24, 2017

 


Biological Control of Pear Psylla 

We began a multi-phase predator monitoring project last year in an attempt to document and quantify levels of biocontrol in pear orchards under conventional, soft and Organic management programs.


Transects
There are nine permanent transects set up in and near the valley, three in each of the three different management types. These transects are 75m long, extending 50m into the orchard and 25m into the native boarder vegetation. The transects are sampled weekly to monitor the numbers of predators along the transect. Sampling is done with beating trays, and predators are counted, collected, and identified. Psylla are also counted, and all unknown specimens are collected for identification.
We are looking at the effects of different spray programs and the proximity of native boarder vegetation on the presence and diversity of predators in the orchards.

                Limb-tap sampling in native vegetation

 

Exclusion Cages
We are in the preliminary stages of an experiment using exclusion cages to estimate actual levels of predation along the gradient from native vegetation to orchard vegetation. Pear leaves infested with sentinel psylla nymphs are prepared in the lab. Pairs of caged and uncaged leaves are set out on the transects, and pear psylla nymphs are monitored for mortality.

                Closeup of cage

Tree Fruit Research & Extension Center, 1100 N Western Ave, Washington State University, Wenatchee WA 98801, 509-663-8181, Contact Us