Temporal variation in arthropod sampling effectiveness: the case for using the beat sheet method in cotton

Abstract

Predatory insects and spiders are key elements of integrated pest management (IPM) programmes in agricultural crops such as cotton. Management decisions in IPM programmes should to be based on a reliable and efficient method for counting both predators and pests. Knowledge of the temporal constraints that influence sampling is required because arthropod abundance estimates are likely to vary over a growing season and within a day. Few studies have adequately quantified this effect using the beat sheet, a potentially important sampling method. We compared the commonly used methods of suction and visual sampling to the beat sheet, with reference to an absolute cage clamp method for determining the abundance of various arthropod taxa over 5 weeks. There were significantly more entomophagous arthropods recorded using the beat sheet and cage clamp methods than by using suction or visual sampling, and these differences were more pronounced as the plants grew. In a second trial, relative estimates of entomophagous and phytophagous arthropod abundance were made using beat sheet samples collected over a day. Beat sheet estimates of the abundance of only eight of the 43 taxa examined were found to vary significantly over a day. Beat sheet sampling is recommended in further studies of arthropod abundance in cotton, but researchers and pest management advisors should bear in mind the time of season and time of day effects.

Eficiência de métodos de amostragem de lagartas e de percevejos na cultura de soja

“…Na prática, o método de amostragem a ser utilizado é determinado pela espécie a ser amostrada, pela precisão desejada, pelo custo de amostragem, pelo tempo necessário e pela reprodutibilidade de resultados (WADE et al, 2006). Neste estudo, ficou evidenciado que há diferença entre os métodos de amostragem, em relação à capacidade de coleta de lagartas e de percevejos, e que o método de amostragem pano-de-batida vertical deve ser o preferido pela sua maior eficácia para as espécies e as idades dos insetos-praga ou para os distintos momentos da fenologia da cultura.…”

“…A escolha do método de amostragem é dependente da cultura, do estádio fenológico, das espécies-alvo, da precisão e exatidão requerida, da facilidade de uso, do tempo e do custo desses métodos (WADE et al, 2006). Métodos de amostragem como o pano-de-batida (BOYER & DUMAS, 1969), o pano-de-batida largo (CORRÊA-FERREIRA & PAVÃO, 2005) e o pano-de-batida vertical (DREES & RICE, 1985) são utilizados para amostragem de insetos-praga na cultura de soja.…”

“…Estudos comparativos entre métodos de amostragem para a coleta de insetos-praga nas culturas de soja (SHEPARD et al, 1974;COSTA & CORSEUIL, 1979;SANE et al, 1999;MASSARO & GAMUNDI, 2003;CORRÊA-FERREIRA & PAVÃO, 2005;GUEDES et al, 2006), de algodoeiro (DEGRANDE et al, 2003;WADE et al, 2006;MUSSER et al, 2007;KNUTSON et al, 2008) e de café (LARA et al, 2008) têm sido realizados. De maneira geral, esses trabalhos evidenciaram que as quantidades de insetos-praga coletadas por meio dos métodos são variáveis.…”

IPM in the transgenic era: a review of the challenges from emerging pests in Australian cotton systems

“…The techniques included: visually searching the crop, the use of suction samplers, sweep netting, and using beat sheets (drop cloths). This research determined that beat-sheet and sweep-net methods were more effective at locating mirids than visual searches or suction sampling (Wade et al 2006), and use of these methods has been extended widely and well adopted by industry (Threlfall et al 2005). Further, calibrations between the different methods were derived using regression and used to adjust thresholds for sampling method (see below).…”

Comparison of beat cloth and entomological net methods for determining faunistic indices of soybean in Rio Grande do Sul, Brazil

“…Estimates of faunistic indices provide information on distribution, richness and abundance of species within a community. The advantage of such indices is that they generate analyzable data, and by definition, they are devoid of unity, allowing comparisons between communities sampled with a nonstandard method (Wade et al, 2006;Haddad et al, 2011;Martins et al, 2012). Therefore, studies on the diversity of beneficial and pest insects have been performed in different crops (Wade et al, 2006;Stürmer et al, 2012).…”