Comparing methods to evaluate the effects of Bt maize and insecticide on spider assemblages

Meissle, Michael; Lang, Andréas

doi:10.1016/j.agee.2004.12.007

Cited by 40 publications

(38 citation statements)

References 28 publications

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“…On the other hand, applications of insecticides such as pyrethroids have shown negative effects on biological control agents (MEN et al, 2004;LANG, 2005). However, in this study, there was no significant effect of Bt maize and insecticides on the abundance of syrphids, earwigs, coccinellids and spiders (Table 3).…”

Section: Transgenic and Chemical Controlcontrasting

confidence: 43%

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Diversity of insects under the effect of Bt maize and insecticides

2018

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ABSTRACT:The genetically modified maize to control some caterpillars has been widely used in Brazil. The effect of Bt maize and insecticides was evaluated on the diversity of insects (species richness and abundance), based on the insect community, functional groups and species. This study was conducted in genetically modified maize MON810, which expresses the Cry1Ab protein from Bacillus thuringiensis Berliner, and conventional maize with and without insecticide sprays (lufenuron and lambda-cyhalothrin) under field conditions in Ponta Grossa (Paraná state, Brazil). Insect samplings were performed by using pitfall trap, water tray trap and yellow sticky card. A total of 253,454 insects were collected, distributed among nine orders, 82 families and 241 species. No differences were observed in the insect community based on the richness, diversity and evenness indices. Predators and pollinators were more abundant in genetically modified maize. Parasitoids, detritivores, sap-sucking herbivores and chewing herbivores were more abundant in conventional maize with insecticide sprays. Significant differences were found for the species Colopterus sp., Colaspis occidentalis (L.) and Nusalala tessellata (Gerstaecker) which were most abundant in Bt maize, and Dalbulus maidis and Condylostylus sp.2 in conventional maize. KEYWORDS:Cry1Ab; biodiversity; pyrethroid; natural enemies. RESUMO:O milho geneticamente modificado visando ao controle de lagartas tem sido amplamente utilizado no Brasil. Em estudo de campo realizado em Ponta Grossa (Paraná, Brasil), compararam-se, com base na diversidade (riqueza de espécies e abundância), os efeitos do milho Bt e do controle químico sobre a comunidade de insetos, grupos funcionais e espécies. A comunidade de insetos foi amostrada no milho geneticamente modificado MON810, que expressa a proteína Cry1Ab de Bacillus thuringiensis Berliner, e no milho convencional com e sem a aplicação de inseticidas (lufenuron e lambda-cialotrina). As amostragens foram realizadas por meio da coleta de insetos utilizando-se armadilha de queda, bandeja-d'água e cartão adesivo. Foram coletados 253.454 insetos, distribuídos em nove ordens, 82 famílias e 241 espécies. Não foram observadas diferenças na comunidade de insetos para os índices de riqueza, diversidade e equitabilidade nos tratamentos avaliados. Predadores e polinizadores foram mais abundantes no milho geneticamente modificado, e parasitoides, decompositores, sugadores e mastigadores, no milho convencional com inseticida. Diferenças significativas foram detectadas para as espécies Colopterus sp., Colaspis occidentalis (L.) e Nusalala tessellata (Gerstaecker), mais abundantes no milho Bt, e Dalbulus maidis e Condylostylus sp.2, mais abundantes no milho convencional. PALAVRAS-CHAVE:Cry1Ab; biodiversidade; piretroide; inimigos naturais.

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Section: Transgenic and Chemical Controlcontrasting

confidence: 43%

“…In contrast, insecticide sprays have shown negative effects on biological control agents LANG, 2005;ROSE;DIVELY, 2007). Therefore, it is expected that the use of transgenic plants will reduce the application of insecticides, a fact that may contribute to biological control.…”

Section: Introductionmentioning

confidence: 99%

Diversity of insects under the effect of Bt maize and insecticides

2018

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“…As herbivore insects were not monitored in this study, this hypothesis may not be confirmed but the gap shows that the main herbivore arthropods in maize should also be monitored if biological control functions have to be measured. A study conducted in Europe to compare spider abundance and richness on Bt vs. non-Bt plants also found no differences between the two kinds of maize varieties (Meissle & Lang, 2005). Statistical analysis of field trials for PMEM of a GM variety aims to test the null hypothesis: there is no difference between the GM vs. a conventional comparator variety in the abundance or activity of a nontarget organism.…”

Section: Discussionmentioning

confidence: 99%

Post-market environmental monitoring of Bt maize in Spain: Non-target effects of varieties derived from the event MON810 on predatory fauna

Albajes

Farinós

Pérez‐Hedo

et al. 2012

Span. j. agric. res.

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The Spanish Government has established post-market environmental monitoring (PMEM) as mandatory for genetically modified (GM) crop varieties cultivated in Spain. In order to comply with this regulation, effects of Bt maize varieties derived from the event MON810 on the predatory fauna were monitored for two years in northeast and central Spain. The study was carried out with a randomized block design in maize fields of 3-4 ha on which the abundance of plant-dwelling predators and the activity-density of soil-dwelling predators in Bt vs. non-Bt near-isogenic varieties were compared. To this end, the plots were sampled by visual inspection of a certain number of plants and pitfall traps 6 or 7 times throughout two seasons. No significant differences in predator densities on plants were found between Bt and non-Bt varieties. In the pitfall traps, significant differences between the two types of maize were found only in Staphylinidae, in which trap catches in non-Bt maize were higher than in Bt maize in central Spain. Based on the statistical power of the assays, surrogate arthropods for PMEM purposes are proposed; Orius spp. and Araneae for visual sampling and Carabidae, Araneae, and Staphylinidae for pitfall trapping. The other predator groups recorded in the study, Nabis sp. and Coccinellidae in visual sampling and Dermaptera in pitfall trapping, gave very poor power results. To help to establish a standardized protocol for PMEM of genetically modified crops, the effect-detecting capacity with a power of 0.8 of each predator group is given.Additional key words: GMO; non-target arthropods; Orius spp.; Staphylinidae; Carabidae; PMEM; statistical power. Resumen Plan de Seguimiento del cultivo de maíz Bt en España: evaluación de los efectos de variedades con el evento MON810 sobre entomofauna no dianaCon el objetivo de cumplir con la legislación española que establece la obligatoriedad de un plan de seguimiento ambiental para post-comercialización (PMEM) para los cultivos modificados genéticamente, se evaluó durante dos años el efecto de variedades de maíz Bt derivadas del evento MON810 en la fauna depredadora, en el nordeste y centro de España. El estudio se realizó mediante un diseño de bloques al azar, en campos de maíz de 3-4 ha, en los cuales se comparó la abundancia/actividad de depredadores en planta y en el suelo entre variedades de maíz Bt y no-Bt. Las parcelas se muestrearon de 6 a 7 veces durante cada uno de los dos años mediante inspección visual de un número determinado de plantas y por medio de trampas de gravedad. No se observaron en general diferencias significativas en la densidad de depredadores en planta y en el suelo entre las variedades Bt y no-Bt y sólo los Staphylinidae mostraron capturas significativamente mayores en parcelas no Bt en el centro de España. En base a la potencia estadística obtenida de los análisis se proponen una serie de artrópodos indicadores para los ensayos de PMEM: Orius spp. y Araneae

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“…Since Bt-crops are intended to replace or reduce applications of conventional insecticides commonly used in agriculture, insecticide treatments should be considered as one reasonable baseline for a comparative risk assessment [1,3,30]. Experiments that included broad spectrum insecticides, such as pyrethroids and organophosphates, have shown consistently reduced abundances of different groups of predators and hymenopteran parasitoids (Bt-maize [47][48][49]; Bt-cotton [42,43,[50][51][52][53]). Side effects of more selective insecticides such as indoxacarb (anoxadiazine) or spinosad (amacrolide) largely depended on the spray frequency [49] whereas systemic insecticides (such as imidacloprid, a neonicotinoid) were found to have no or little effect on natural enemies [54].…”

Section: Higher-tier Studies In the Fieldmentioning

confidence: 99%