Assessing the effects of Bt cotton on generalist arthropod predators.

Abstract

This chapter illustrates the particular application of the scientific methodology (used during the pre-release stages of Bt cotton) supporting the risk assessment of nontarget organisms and biodiversity to generalist arthropod predators in Brazil. The steps in the methodology (i.e. species selection, listing and prioritizing nontarget species and processes, identifying trophically mediated exposure pathways to transgenic plant and transgene products, identifying possible adverse effect scenarios for trophically mediated and other ecological effects, and testing hypotheses and experimental designs to test causal chains of events associated with specific exposure pathways and adverse effect scenarios) as applied to generalist arthropod predators, are discussed.

Limitations in dose–response and surrogate species methodologies for risk assessment of Cry toxins on arthropod natural enemies

“…Nontarget species likely to be highly exposed to the environmental stressor and to contribute significantly to the ecological function are selected. For example, C. sanguinea is a common arthropod predator in cotton in Brazil (Faria et al 2006) and provides important biological control of cotton aphids. As it is likely to be exposed to Bt cotton through bi-or tritrophic exposure, it could be used to evaluate the potential effects of Bt cotton on biological control agents in Brazil.…”

Bitrophic toxicity of Cry1Ac to Cycloneda sanguinea, a predator in Brazilian cotton

“…Ladybeetles are widely regarded as important biological control agents in agricultural habitats. Five species dominate the ladybeetle community associated with cotton in Brazil (Faria et al., ), and an analysis of the behavioral and physiological traits of these species (Oliveira et al., ), and the community composition on cotton in Central Brazil (EMG Fontes, CSS Pires & ER Sujji, unpubl.) has indicated that C. sanguinea is the most significant coccinellid predator and one of the priority candidates for ecological non‐target risk assessment of genetically modified (GM) cotton (Faria et al., ).…”

“…Five species dominate the ladybeetle community associated with cotton in Brazil (Faria et al., ), and an analysis of the behavioral and physiological traits of these species (Oliveira et al., ), and the community composition on cotton in Central Brazil (EMG Fontes, CSS Pires & ER Sujji, unpubl.) has indicated that C. sanguinea is the most significant coccinellid predator and one of the priority candidates for ecological non‐target risk assessment of genetically modified (GM) cotton (Faria et al., ). This species is abundant in the tropical and subtropical range of the New World (Gordon, ) and is reported to be a dominant predator in several crops in Florida (USA) (Michaud, ), Central and South America (Vandenberg & Gordon, ), and in Brazil (Santa‐Cecilia et al., ; Oliveira et al., ).…”