Insects (2017) 8 (4 - 105)

K.G. Amarasekare and P.W. Shearer (2017)
Stability of Cacopsylla pyricola (Hemiptera: Psyllidae) populations in Pacific Northwest pear orchards managed with long-term mating disruption for Cydia pomonella (Lepidoptera: Tortricidae)
Insects 8 (4 - 105)
Abstract: This study focused on conservation biological control of pear psylla, Cacopsylla pyricola, in the Pacific Northwest, USA. We hypothesized that insecticides applied against the primary insect pest, codling moth Cydia pomonella, negatively impact natural enemies of pear psylla, thus causing outbreaks of this secondary pest. Hence, the objective of this study was to understand how codling moth management influences the abundance of pear psylla and its natural enemy complex in pear orchards managed under long-term codling moth mating disruption programs. We conducted this study within a pear orchard that had previously been under seasonal mating disruption for codling moth for eight years. We replicated two treatments, "natural enemy disrupt" (application of two combination sprays of spinetoram plus chlorantraniliprole timed against first-generation codling moth) and "natural enemy non-disrupt" four times in the orchard. Field sampling of psylla and natural enemies (i.e., lacewings, coccinellids, spiders, Campylomma verbasci, syrphid flies, earwigs) revealed that pear psylla populations remained well below treatment thresholds all season despite the reduced abundance of key pear psylla natural enemies in the natural enemy disrupt plots compared with the non-disrupt treatment. We speculate that pear psylla are difficult to disrupt when pear orchards are under long-term codling moth disruption.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: English)
Full text of article
Database assignments for author(s): Kaushalya G. Amarasekare, Peter W. Shearer

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

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Cydia pomonella	Pear (Pyrus)	U.S.A. (NW)
	Cacopsylla pyricola	Pear (Pyrus)	U.S.A. (NW)
Cycloneda munda (predator)	Cacopsylla pyricola	Pear (Pyrus)	U.S.A. (NW)
Hippodamia convergens (predator)	Cacopsylla pyricola	Pear (Pyrus)	U.S.A. (NW)
Campylomma verbasci (predator)	Cacopsylla pyricola	Pear (Pyrus)	U.S.A. (NW)