Impacto causado por deltametrina em coleópteros de superfície do solo associados à cultura do milho em sistemas de plantio direto e convencional

Abstract

Deltamethrin is one of the most frequently used insecticide in Brazilian maize fields aiming to control the fall armyworm, Spodoptera frugiperda J.E. Smith (Lepidoptera: Noctuidae). Despite the fact that the toxicology of this insecticide is well known, there is little information about its impact on Neotropical Coleoptera. Therefore our objective was to evaluate the deltamethrin effect on the Coleoptera assemblage associated with maize crops. The treatments used were conventional and no tillage cultivation with or without deltamethrin sprays. There was significant effect of the cultivation system on the species assemblage selected for analysis. The effect of deltamethrin was only detected in the conventional cultivation system, while no significant effect of insecticide spraying was observed on the Coleoptera assemblage associated with the maize crop, suggesting a buffer effect provided by this cultivation system in the impact caused by the insecticide.

Non‐target impact of deltamethrin on soil arthropods of maize fields under conventional and no‐tillage cultivation

“…Despite the lack of an overall trend regarding the impact of deltamethrin on soil arthropod assemblage, such effects on individual species may exist, resembling that reported in other studies from tropical areas (Marquini et al. 2002; Araújo et al. 2004).…”

“…No-tillage cultivation systems usually favour microarthropod populations, particularly those of mites and springtails (Stinner and House 1990;McLaughlin and Mineau 1995). Such cultivation systems also affect species of Coleoptera (Perner and Malt 2003;Arau´jo et al 2004). Thus arthropods in no-tillage systems may be more susceptible to insecticides applied to the plant canopy than those in the conventional cultivation system (Edwards and Lofty 1978;Brust et al 1985).…”

“…In addition, as the no-tillage cultivation system commonly employed in Brazil includes a pre-sowing application of herbicides as desiccants (Fornasieri 1992;Guedes and Guedes 2001), the no-tillage impact on soil arthropods is likely to be further enhanced (Moore et al 1984;Salminen et al 1997). Curiously though, the impact of insecticides on arthropods associated with no-tillage cultivation systems has proved negligible in the few studies carried out so far in the tropics, in contrast to that which usually takes place in the temperate zone (Frampton 1997(Frampton , 1999Michereff-Filho et al 2002aArau´jo et al 2004;Badji et al 2004). These findings in tropical areas suggest that no-tillage cultivation may buffer the insecticide impact under short-term exposure.…”

Ecotoxicological Study of Insecticide Effects on Arthropods in Common Bean

“…The reduction of natural enemy populations was expected to result from insecticide application due to the lower availability of shelter and food ( Parra et al. 2002 , Araújo et al. 2004 ).…”

Efeito da soja geneticamente modificada DAS-81419-2, que expressa as proteínas Cry1Ac e Cry1F, sobre os organismos-alvo e na comunidade de artrópodes não-alvo

“…The lack of insecticide effects in short-term studies of arthropod communities has also been detected in other ecosystems, particularly tropical agroecosystems (Chong et al, 2007;Guedes et al, 2016), where the cultivation system itself usually exhibits a more prominent effect and may buffer the potential insecticide impact (Araújo et al, 2004;Badji et al, 2004Badji et al, , 2006Badji et al, , 2007. While Bt proteins are constitutively expressed in the crop throughout the growing season, there is a lack of significant short-and long-term impacts on arthropod assemblages, as reported for maize (Dutton et al, 2003;Dively, 2005), cotton (Naranjo, 2005;Marvier et al, 2007;Torres & Ruberson, 2005;Yao et al, 2016) and soybean (Yu et al, 2014).…”