Effects of genetically modified maize events expressing Cry34Ab1, Cry35Ab1, Cry1F, and CP4 EPSPS proteins on arthropod complex food webs

Abstract

Four genetically modified (GM) maize (Zea mays L.) hybrids (coleopteran resistant, coleopteran and lepidopteran resistant, lepidopteran resistant and herbicide tolerant, coleopteran and herbicide tolerant) and its non‐GM control maize stands were tested to compare the functional diversity of arthropods and to determine whether genetic modifications alter the structure of arthropods food webs. A total number of 399,239 arthropod individuals were used for analyses. The trophic groups’ number and the links between them indicated that neither the higher magnitude of Bt toxins (included resistance against insect, and against both insects and glyphosate) nor the extra glyphosate treatment changed the structure of food webs. However, differences in the average trophic links/trophic groups were detected between GM and non‐GM food webs for herbivore groups and plants. Also, differences in characteristic path lengths between GM and non‐GM food webs for herbivores were observed. Food webs parameterized based on 2‐year in‐field assessments, and their properties can be considered a useful and simple tool to evaluate the effects of Bt toxins on non‐target organisms.

Sopas de diversidad para el análisis y monitoreo de artropofauna en ambientes antropizados

“…Para ejemplificar lo anterior podemos citar el caso del maíz genéticamente modificado (gm) y su efecto sobre las redes tróficas de los coleópteros. Al comparar el número de interacciones formadas alrededor de maíz gm y no gm se encontró que la segunda tiene mayor número de conexiones y solidez, a consecuencia de la alta conectividad entre los nodos (Pálinkás et al, 2017).…”

Enfrentando el reto de evaluar los daños ambientales ocasionados por organismos genéticamente modificados

“…Un claro ejemplo es la alteración en la tasa de sobrevivencia y fecundidad de los pulgones Aphis gossypii y Myzus persicae cuando son afectados por Cry1A+CpTI y nptII (Alla et al, 2003) respectivamente, que fueron diseñados para controlar plagas específicas de lepidópteros (Liu et al, 2005) y aunque aún no está reportado un efecto adverso, está demostrado que el transgén puede estar presente en los depredadores de los organismos blanco (Harwood et al, 2005;Obrist et al, 2006). Por otro lado, a nivel comunidad, se ha observado la modificación de las interacciones y diversidad de la artropofauna debido a la alteración que tienen las poblaciones de organismos blanco (Sosa y Almada, 2014 ;Pálinkás et al, 2017). Otro reporte de alteración a nivel comunidad en nematodos es el de Liu y colaboradores (2015).…”

Arthropods dataset from different genetically modified maize events and associated controls

“… 5 . While several previous studies have assessed the effects of GM maize toxins (especially Bt toxins) on non-target (particularly predatory) arthropods 3 , 11–16 , few studies have focussed on the strength of species’ trophic interactions and associated parameters among GM maize systems. This lack of knowledge represents a major issue in the analyses of arthropod communities associated with different GM plant species 17 .…”

“…Arthropod community studies in GM crop systems must involve a comprehensive and multi-methodological field assessment based on different collection methods of all arthropods and weeds from several different GM and non-GM control crops, over several years and throughout the maize growing season. Such datasets may allow us to assess the functional diversity of arthropod communities in GM and non-GM crops to be analysed at the same time, providing consistent species abundance and prey preference data 1 , 3 , 18 . However, datasets with hundreds of thousands of arthropod individuals from GM maize and its non-GM controls are rare, with no such datasets being freely available until now.…”

“…However, datasets with hundreds of thousands of arthropod individuals from GM maize and its non-GM controls are rare, with no such datasets being freely available until now. The analysis of such data may demonstrate that interactions between species are highly correlated, and can thus be considered a useful tool in assessing the deleterious effects of Bt , and other toxins on a wide range of non-target organisms in GM croplands 1 , 3 . These data can also be a useful tool to develop biosafety risk hypotheses for invertebrates exposed to GM plants 18–20 .…”