Glyphosate-based herbicides toxicity on life history parameters of zoophytophagous Podisus nigrispinus (Heteroptera: Pentatomidae)

Abstract

The increase of agricultural areas with glyphosate-resistant (GR) crops, and use of this herbicide in Brazil, makes necessary to assess its impacts on non-target organisms. The objective was to evaluate the development, reproduction and life table parameters of Podisus nigrispinus (Heteroptera: Pentatomidae) reared on GR-soybean plants treated with glyphosate formulations (Zapp-Qi, Roundup-Transorb-R and Roundup-Original) at the recommended field dose (720g acid equivalent ha). Glyphosate formulations had no affect on nymph and adult weight of this predator. Fourth instar stage was shortest with Zapp Qi. Egg-adult period was similar between treatments (26 days) with a survival over 90%. Zapp-Qi and Roundup-Transorb-R (potassium-salt: K-salt) reduced the egg, posture and nymph number per female, and the longevity and oviposition periods of this predator. Podisus nigrispinus net reproductive rate was highest in GR-soybean plants treated with Roundup-Original (isopropylamine-salt: IPA-salt). However, the duration of one generation, intrinsic and finite increase rates, and time to duplicate the population, were similar between treatments. Glyphosate toxicity on P. nigrispinus depends of the glyphosate salt type. IPA-salt was least harmless to this predator. Formulations based on K-salt altered its reproductive parameters, however, the development and population dynamic were not affect. Therefore, these glyphosate formulations are compatible with the predator P. nigrispinus with GR-soybean crop.

Impaired associative learning after chronic exposure to pesticides in young adult honey bees

“…Adverse effects of glyphosate have been found on several animal species, including honey bees. Although the mode of action of this herbicide in insects is still unknown, parameters affected include development, reproduction, navigation, gustatory perception and olfactory learning (Balbuena et al, 2015;Helmer et al, 2015;Herbert et al, 2014;Thompson et al, 2014;Zanuncio et al, 2018). Therefore, it is reasonable to worry about its influence on pollinators.…”

Glyphosate ban in Mexico: potential impacts on agriculture and weed management

“…Robust studies have shown that the active principle of pure glyphosate can have impacts on soil fauna, but not the formulations 72 and vice versa, i.e., results are often divergent. Different formulations of potassium salt and/or isopropylamine salt of glyphosate did not cause side effects on the predator Podisus nigrispinus 73 . However, some adjuvants led to more harmful outcomes than glyphosate itself.…”

Effect of herbicides on the emergence of Sitophilus zeamais (Coleoptera: Curculionidae) in transgenic Bt maize

“…The effect of herbicides on insect populations in maize fields should be considered in integrated pest management (IPM), since the molecules of these chemicals can have deleterious effects on arthropod species, including beneficial insects (de Menezes & Soares, 2016;Zanuncio et al, 2018). However, the interactions of different herbicides with different crop genotypes and insect species are particular (De Souza et al, 2020), making it difficult to obtain accurate information on the subject.…”