Impact of Vineyard Pesticides on a Beneficial Arthropod, Typhlodromus pyri (Acari: Phytoseiidae), in Laboratory Bioassays

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.

Side Effects of Sulfur Dust on the European Grapevine Moth Lobesia botrana and the Predatory Mite Kampimodromus aberrans in Vineyards

“…However, wettable sulfur was not effective against the leafhopper Erythroneura elegantula Osborn (Hemiptera: Cicadellidae) [36]. In vineyards, negative side effects of sulfur dust on natural enemies, including phytoseiid mites, have also been observed [36][37][38][39][40][41][42].…”

Current understanding of grapevine defense mechanisms against the biotrophic fungus (Erysiphe necator), the causal agent of powdery mildew disease

“…Indeed, a report on the use of fungicides in the European Union over the period 2001–2003 indicated that while viticulture only accounted for 3.3% of the agricultural area, a staggering 81,000 tonnes of active substance were applied annually to grapevines in European vineyards, which represented 67% of all fungicides applied to crops in the EU 3 . Not only does this translate into increased production costs for growers, but there is also the potential impact of these chemicals on the health of beneficial organisms in the vineyard 4 and vineyard workers 5 , as well as increased carbon emissions generated from their frequent application. Thus, the integration of effective genetic resistance into grape cultivars would reduce the dependence of viticulture on chemical inputs, leading to significant financial, health, and environmental benefits.…”

Dinâmica populacional de Calepitrimerus vitis (Nalepa) (Acari: eriophyidae) em cultivares de videira na região da campanha do Rio Grande do Sul

“…O crescimento populacional de C. vitis no vinhedo varia conforme as condições climáticas, com a composição e a quantidade de ácaros predadores e ainda com os tratamentos fitossanitários realizados (DUSO; VETTORAZZO, 1999;GADINO et al, 2011). Em condições de temperatura constante, o tempo de uma geração de C. vitis varia de 5,5 dias a 28 e 30ºC até 17,5 dias a 17ºC, enquanto a fecundidade oscila de 0,2 ovo a 17ºC até 26,1 ovos a 25ºC, com possibilidade de até 14 gerações desta espécie por estação de crescimento (WALTON et al, 2010).…”