Environmental Entomology (1983) 12, 222-226

R.E. Fye (1983)
Impact of volcanic ash on pear psylla (Homoptera: Psyllidae) and associated predators
Environmental Entomology 12 (1), 222-226
Abstract: Populations of pear psylla, Psylla pyricola Foerster, in pear orchards receiving ca. 6 mm of volcanic ash from the eruption of Mt. St. Helens on 18 May 1980, continued to expand as in previous years. Orchards receiving 2.5 to 4.5 cm of ashfall generally had lower populations of pear psylla. Laboratory tests with whole ash and a fine fraction indicated that a 70 to 80% reduction of a generation of pear psylla exposed to the ash could be expected. Populations of winged predators were decimated, but Deraeocoris brevis (Uhler) populations revived due to oviposition in leaf tissue before the eruption.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)

Research topic(s) for pests/diseases/weeds:
environment - cropping system/rotation
population dynamics/ epidemiology
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Cacopsylla pyricola	Pear (Pyrus)	U.S.A. (NW)
Deraeocoris brevis (predator)	Cacopsylla pyricola	Pear (Pyrus)	U.S.A. (NW)