Journal of Economic Entomology (2011) 104, 970-977

Angela N. Gadino, Vaughn M. Walton and Amy J. Dreves (2011)
Impact of vineyard pesticides on a beneficial arthropod, Typhlodromus pyri (Acari: Phytoseiidae), in laboratory bioassays
Journal of Economic Entomology 104 (3), 970-977
Abstract: Laboratory bioassays were conducted to evaluate the effects of six vineyard pesticides on Typhlodromus pyri Scheuten (Acari: Phytoseiidae), a key predator of the mite Calepitrimerus vitis Nalepa (Acari: Eriophyoidae), in Pacific coastal vineyards. Materials tested were whey powder, 25% boscalid + 13% pyraclostrobin (Pristine), 40% myclobutanil (Rally), micronized sulfur (92% WP), 75% ethylene bisdithiocarbamate (mancozeb; Manzate), and 91.2% paraffinic oil (JMS Stylet), all applied at three concentrations. Pesticide dilutions were directly sprayed onto T. pyri adult females and juveniles, and each treatment was assessed to determine effects on direct mortality and fecundity. Five of the six pesticides tested resulted in <50% mortality to adult and juvenile T. pyri for all concentrations 7 d after treatment. Paraffinic oil treatments displayed direct mortality >50% for adult and juvenile assays and resulted in significantly higher mortality. Sublethal effects were more pronounced than acute pesticide toxicity, particularly in juvenile mite bioassays. Significant decreases in fecundity were detected in the sulfur and mancozeb treatments compared with the control in juvenile tests. The relative percentage of fecundity reduction for juvenile mites was highest when applying mancozeb (>70%), sulfur (>25%), or myclobutanil (>20%). Adult mites displayed the greatest reductions in fecundity from applications of paraffinic oil (>20%) or mancozeb (>15%) treatments. Boscalid (+ pyraclostrobin) and whey displayed the least effect on fecundity across all bioassays. These results can be used to develop management guidelines in vineyard pest management practices to help conserve and enhance predatory mite populations.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Vaughn Martin Walton

Research topic(s) for pests/diseases/weeds:
health/environmental effects of pesticides
Research topic(s) for beneficials or antagonists:
resistance to pesticides

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Calepitrimerus vitis	Grapevine (Vitis)	U.S.A. (NW)
Typhlodromus pyri (predator)	Calepitrimerus vitis	Grapevine (Vitis)	U.S.A. (NW)