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

William Cristian Da Silva Pizzaia,Vagner De Alencar Arnaut De Toledo,Angélica De Souza Khatlab,Maria Claudia Colla Ruvolo-Takasusuki,Naiara Climas Pereira,Tamiris De Oliveira Diniz,Eliane Gasparino,Adriana Aparecida Sinópolis-Gigliolli,Breno Gabriel Da Silva

doi:10.33448/rsd-v10i2.12109

William Cristian Da Silva Pizzaia, Vagner De Alencar Arnaut De Toledo + Show 7 more

Open Access

https://doi.org/10.33448/rsd-v10i2.12109

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Abstract

Honeybees are the insect most used for pollination purposes due to its efficient characteristics for this function, which reflects in positive aspects for both nature and man. The expansion of agriculture and the development of agrochemicals to combat pests has had negative impacts on honeybee health, causing its disappearance around the world. This research aimed to evaluate the effects of honeybee exposure to the neonicotinoid insecticide thiamethoxam on its survival rate, as well as on morphological and histological changes in the midgut of adult workers from the F4 generation of Apis mellifera queens tolerant to thiamethoxam and non-tolerant worker honeybees. After the bioassays, the midgut was removed for morphological evaluation. The results showed that F4 bees were more tolerance to thiamethoxam and exhibited less significant morphological changes when compared to the non-tolerant control group.

Highlights

In 1956, African honeybees (Apis mellifera scutellata) arrived in Brazil from Africa
The Africanized population was able to adapt to the tropical climate, developing characteristics for its survival, such as temperature control, nest organization and tolerance to some diseases and pathogens (Bourgeois et al, 2016)
Toxicity in workers tolerant to thiamethoxan After oral contamination of A. mellifera with thiamethoxam, workers survival was affected, the average and median of survival levels were higher in the candy treatments, especially in the control group (Figure 1)

Summary

Introduction

In 1956, African honeybees (Apis mellifera scutellata) arrived in Brazil from Africa. The Africanized population was able to adapt to the tropical climate, developing characteristics for its survival, such as temperature control, nest organization and tolerance to some diseases and pathogens (Bourgeois et al, 2016). A. mellifera is one of the best-studied species in the world, due to its significant services to the environment and its disappearance, due to factors such as deforestation, climate change and indiscriminate use of agrochemicals, is raising concern (Stein et al, 2017; Sanchez-Bayo et al, 2016; Oliveira et al, 2018). The excessive use of agrochemicals in doses above the permitted favors the significant loss of pollinating insects, which can compromise the development of plant species and the survival of all living organisms that depend on plants for a living (Sanchez-Bayo et al, 2016; Oliveira et al, 2018; Chambers et al, 2019)

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