Sticking the landing, post-harvest psylla populations
by Chris McCullough, Robert Orpet, Molly Sayles, and Louis Nottingham
November 7, 2022
- During the 2022 pear growing season, our WSU pear entomology team monitored pear psylla and its natural enemies (predators and parasitoids) across orchards in the Wenatchee Valley.
- Orchards were either conventional, organic, or followed our new phenology-based Integrated Pest Management (IPM) program (detailed in this link: http://treefruit.wsu.edu/crop-protection/psylla-phenology-model). All programs experienced highs and lows in terms of pear psylla.
- Conventional had great control of pear psylla during summer. However, as harvest approached, the elimination of natural enemies resulted in pear psylla nymph populations dramatically increasing (Figure 1).
- Meanwhile, in organic and IPM orchards, natural enemy populations increased and kept pear psylla nymph abundance lower than in conventional orchards (Figure 1).
- These differing scenarios meant a tradeoff between early-season damage in IPM and organic orchards vs. a sticky harvest and the risk of late-season damage in conventional orchards.
- We evaluated damage in the field, and pear psylla marking downgrades averaged out to be similar between IPM and conventional orchards.
Read the whole article on the WSU Tree Fruit site.
