Insecticide resistance, control failure likelihood and the First Law of Geography

Abstract

Insecticide resistance is a broadly recognized ecological backlash resulting from insecticide use and is widely reported among arthropod pest species with well-recognized underlying mechanisms and consequences. Nonetheless, insecticide resistance is the subject of evolving conceptual views that introduces a different concept useful if recognized in its own right - the risk or likelihood of control failure. Here we suggest an experimental approach to assess the likelihood of control failure of an insecticide allowing for consistent decision-making regarding management of insecticide resistance. We also challenge the current emphasis on limited spatial sampling of arthropod populations for resistance diagnosis in favor of comprehensive spatial sampling. This necessarily requires larger population sampling - aiming to use spatial analysis in area-wide surveys - to recognize focal points of insecticide resistance and/or control failure that will better direct management efforts. The continuous geographical scale of such surveys will depend on the arthropod pest species, the pattern of insecticide use and many other potential factors. Regardless, distance dependence among sampling sites should still hold, following the maxim that the closer two things are, the more they resemble each other, which is the basis of Tobler's First Law of Geography. © 2016 Society of Chemical Industry.

Susceptibility of Cypriot Tuta absoluta populations to four targeted insecticides and control failure likelihood

“…Moreover, the estimated LC 80 and LC 95 were compared to the maximum recommended label rate (RLR max ) to estimate the possibility of insecticide control failure based on Silva et al () and Roditakis, Skarmoutsou, and Staurakaki (). The likelihood of an insecticide control failure could be estimated by comparing the predicted % mortality at the label rate to an 80% threshold (Guedes, ). The RLR max for Cyprus was as follows: chlorantraniliprole: 42 mg/L; indoxacarb: 37.5 mg/L; emamectin benzoate: 14.2 mg/L; and spinosad: 120 mg/L.…”

Wolbachiastrains, and lack of genetic diversity and parthenogenesis in Brazilian populations ofTuta absoluta(Lepidoptera: Gelechiidae)

“…This species is already present in China’s neighbouring countries, and it is edging towards Mexico in North America (Campos et al., ; Biondi et al., ). The tomato pinworm is difficult to control particularly in open‐field cultivation requiring intensive use of insecticides and exhibiting increasing problems of insecticide resistance (Biondi et al., ; Desneux et al., ; Gontijo et al, ; Guedes, ; Guedes & Picanço, ; Guedes & Siqueira, ). Among the management tactics used against the tomato pinworm, pheromone‐trapping and mating disruption have been the target of attention since the late 1990s after the identification and test of the species’ pheromone blend (Ferrara et al., ; Michereff Filho et al., ).…”

Sublethal Doses of Insecticides Affect the Fecundity and Fertility of the <i>Chrysodeixis includens</i>?

“…During the phytosanitary management of the crop, application failures may occur [8], resulting in the exposure of the pest to insecticide sublethal doses, according to results found, where changes in the biology and reproduction of C. includens were observed through the toxic action of sublethal doses of insecticides B. thuringiensis, Indoxacarb and Teflubenzuron. This is because insect exposure to a sublethal concentration of insecticide may not lead to target pest death, but may affect biochemical reactions and physiological processes at secondary sites of action [7].…”

“…The use of active principles with different modes of action is suggested as a tool of phytosanitary protection [7], in order to avoid the occurrence of problems related to resistance of insect pests [8]. Based on this premise the present study had the purpose of evaluating the toxicity of different insecticides on the soybean looper (C. includens), being found that the active principles B. thuringiensis, Indoxacarb and Teflubenzuron can be used in the management of C. includens, because the values obtained for LC 50 were similar to those reported in the literature for other pest lepidoptera, such as H. armigera [7] [11] [19].…”

“…Since control failures during management [8] may result in exposure of the pest to sublethal doses [7]. In addition, insects that survive after toxic exposure to an insecticide may present changes in biological, reproductive, behavioral and physiological parameters [6] [9].…”