Toxicity and effects of combined agrochemical in Scaptotrigona bipunctata bees

Abstract

The commercial insecticide Fastac Duo is a combined insecticide, widely used in different crops, acting on insects, affecting both pests and pollinators, such as bees. In this study, the effects of sublethal concentrations of Fastac Duo in stingless bees Scaptotrigona bipunctata were evaluated. Worker forager bees were exposed to the insecticide and histochemical and morphological analyses were conducted after 24, 48 and 72 h of ingestion. Brain analysis of S. bipunctata revealed changes in the chromatin condensing state according to exposure time and insecticide concentration when compared to the control group. Morphological changes were observed in the midgut in all concentrations and exposure times, which may interfere in several physiological processes. In conclusion, although the concentrations used in the study did not cause high mortality, it induced changes in the internal morphology that can lead to changes in bee activity.

Toxicological and morphological analysis of Africanized Apis mellifera selected for tolerance to the neonicotinoid thiamethoxam

“…Similar effects were identified by Diniz et al (2020) after oral contamination of Scaptotrigona bipunctata bees with a combined insecticide containing the neonicotinoid and pyrethroid chemical groups. In this study, several morphological Research, Society and Development, v. 10, n. 2, e14310212109, 2021 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v10i2.12109 changes were observed in the midgut, such as the degradation of the peritrophic membrane, epithelium disorganization and the musculature loosening.…”

Secondary effect of in-hive Metronidazole application on some biological, histological and biochemical activities of Honeybee workers (Apis mellifera L.)

“…In contrast, severe histological alterations in the midgut tissues of worker bees in the flagyl group were observed. Among the most noticeable changes was the partial rupture in columnar cells, which may contribute to the rapture of the peritrophic membrane that acts as a food envelope and protective barrier against various physical, chemical, and microbial food components (Terra, 1996;Diniz et al, 2020). In addition, Spread of cytoplasmic vacuoles in epithelium columnar and separation of muscle layer.…”

Analysis of a dose-response assay in Scaptotrigona bipunctata bees, Lepeletier, 1836 (Hymenoptera: Apidae) using the logistic regression model under the Bayesian approach

“…In a study conducted by Diniz et al (2020b) the estimated LC50 for Scaptotrigona bipunctata bees orally contaminated with the insecticide Fastac Duo were 0.07 g a.i. L -1 to 24 hours, 0.10 g a.i.…”

“…Oral contamination of insects at sublethal doses of agrochemicals can harm their organs (Catae et al, 2014;Diniz et al, 2020b). Catae et al (2014) investigated the effects of the neonicotinoid thiamethoxam on the midgut and Malpighi tubule of A. mellifera and the results indicated that the insecticide is cytotoxic to bees.…”

“…In the literature, there are few dose-response studies for stingless bees (LC50), (Dorneles, Souza Rosa, & Blochtein, 2017;Moreira et al, 2018;de Jacob, Zanardi, Malaquias, Silva, & Yamamoto, 2019;Diniz et al, 2020b;Rosa-Fontana, Dorigo, Galaschi-Teixeira, Nocelli, & Malaspina, 2020), however, none of these studies analyzed the exposure of Scaptotrigona bipunctata bees to the insecticide Fastac Duo. Also, considering statistical methods, the studies mentioned used classical approaches in their analyses, such as logistic regression, probit regression, parametric and non-parametric tests.…”