Ecotoxicological effects of the insecticide fipronil in Brazilian native stingless bees Melipona scutellaris (Apidae: Meliponini)

Abstract

Melipona scutellaris Latreille, 1811 (Hymenoptera, Apidae) is a pollinator of various native and cultivated plants. Because of the expansion of agriculture and the need to ensure pest control, the use of insecticides such as fipronil (FP) has increased. This study aimed to evaluate the effects of sublethal doses of FP insecticide on M. scutellaris at different time intervals (6, 12, and 24 h) after exposure, via individually analyzed behavioral biomarkers (locomotor activity, behavioral change) as well as the effect of FP on different brain structures of bees (mushroom bodies, antennal cells, and optic cells), using sub-individual cell biomarkers (heterochromatin dispersion, total nuclear and heterochromatic volume). Forager bees were collected when they were returning to the nest and were exposed to three different concentrations of FP (0.40, 0.040, and 0.0040 ng a.i/bee) by topical application. The results revealed a reduction in the mean velocity, lethargy, motor difficulty, paralysis, and hyperexcitation in all groups of bees treated with FP. A modification of the heterochromatic dispersion pattern and changes in the total volume of the nucleus and heterochromatin were also observed in the mushroom bodies (6, 12, and 24 h of exposure) and antennal lobes (6 and 12 h) of bees exposed to 0.0040 ng a.i/bee (LD). FP is toxic to M. scutellaris and impairs the essential functions required for the foraging activity.

Three-dimensional reconstruction of corpora allata nucleus reveals insights into epigenetic mechanisms of caste differentiation in Melipona scutellaris stingless bees

“…The methodology adopted to analyze and quantify the volume of the nuclei and heterochromatin in M. scutellaris cells is shown in Figure 1 and described elsewhere (de Morais et al 2018). The following sections describe each step of the methodology.…”

Toxicity of Fenpyroximate, Difenoconazole and Mineral Oil on Apis mellifera L. Introduction

“…Bees could be, multiple times, exposed to the same active ingredient or more than one, which may affect the immune system by developing chronic problems, aggravating secondary effects (Whitehorn et al, 2012;Morais et al, 2018). Exposure of bees to pesticides could become even more harmful, since there is the possibility of repeated, simultaneous and synergistic exposure among and between different chemical groups (Luttik et al, 2012).…”

“…Originally, the relationship between plant and pollinator was essentially positive; however, pollinators are suffering from the frequent use of pesticides in floral resources (Blacquière et al, 2012;Fürst et al, 2014;Morais et al, 2018). Bees are some of the main pollinating agents and have become the most affected individuals, due to the contact with contaminated sources that cause behavioral disorders and even death of individuals (Sandrock et al, 2014;Goulson, 2015).…”

Echovivarium, Um Espaço De Cultivo Para Dar Vida À Sua Casa

“…Na agricultura há grande utilização de pesticidas. E muitos relatos fortalecem a hipótese de que estes estariam colaborando com o desaparecimento das abelhas em campo, por apresentarem danos nocivos às abelhas (DE MORAIS et al, 2018).…”