A study on lethal doses of various pesticides on honeybees (Apis mellifera L.) – a laboratory trial

Abstract

Exposure of honeybee (Apis mellifera L.) to pesticides disturbed normal physiological and behavioral functions required for normal foraging and colony maintenance. The present study was aimed towards establishing the mean lethal concentration (LC50) of three pesticides viz. carbamate (carbaryl), organophosphate (chlorpyrifos) and neonicotinoid (imidacloprid) in honeybees through feeding bioassay laboratory trial. Deleteriousness was confirmed through mortality rate, number of survival bees, acetylcholinesterase (AChE), total protein (TP) levels, AChE gene transcription level, and gut tissues histological analysis of exposed honeybees. Mean mortality rate was calculated for 96 h interval at three different concentrations of tested pesticides (5, 2.5, and 1.25 mg L−1), and LC50 values calculated for 48 and 96 h interval. AChE enzyme and TP level are determined by ELIZA and spectrophotometer, respectively. Results revealed that imidacloprid had the lowest LC50 (0.477 ng/bee) values as compared with carbaryl and chlorpyrifos. High mortality rate was observed at highest dose, being impidacloprid have more lethal effects as compared with other pesticides. Similarly, biochemical analysis revealed that imidiacloprid and chlorpyrifos significantly (P ≤ 0.05) increased AChE and TP levels, whereas carbaryl significantly (P ≤ 0.05) decreased them. Similarly, probe based RT qPCR revealed that imidacloprid and chlorpyrifos treatments significantly (P ≤ 0.05) enhanced the AChE level whereas carbaryl decreased it. Histological analysis showed that the gut tissues of honeybees exposed to pesticide treatment had substantial morphological abnormalities. In a nutshell, imidacloprid, carbaryl and chlorpyrifos have substantial toxic effects on all the study attributes of honeybees with imidacloprid being most toxic.

Physiological Responses of the Firefly Pyrocoelia analis (Coleoptera: Lampyridae) to an Environmental Residue From Chemical Pesticide Imidacloprid

“…Thus, significant oxidative damage was observed in the tissues and cells in our study while ROS in eukaryotic cells is commonly produced during cellular respiration ( Juan et al, 2021 . In previous studies, similar damage was also reported in honeybees ( Apis mellifera L.) after 72 h of pesticide exposure ( Pervez and Manzoor, 2020 ). Dittbrenner et al (2011) showed that there was significant damage to the midgut tissue in Eisenia fetida for all imidacloprid exposure times (1, 7, and 14 days).…”

“…The exposure to imidacloprid led to changes in the biochemical parameters of the Pacific white shrimp Litopenaeus vannamei , which caused oxidative stress, retarded growth, and immune and tissue damage ( Fu et al, 2022 ). Pervez and Manzoor (2020) found that physiological and behavioral functions for normal foraging and colony maintenance were modified in honeybees ( Apis mellifera ) exposed to 1.25, 2.5, and 5 mg L −1 imidacloprid, respectively.…”

Biodiversity and Challenges of Honey Bee Population in Pakistan

“…They observed that emamectin benzoate exhibited the highest toxicity with an LD50 value of 1.02 µg/mL, followed by spinetoram (1.10 µg/mL), chlorantraniliprole (2.74 µg/mL), imidacloprid (3.09 µg/mL), flonicamid (3.94 µg/mL), and fipronil (6.00 µg/mL). Another study conducted in Pakistan revealed that the LD50 of neonicotinoid (imidacloprid) was the lowest (0.477 ng/bee) compared to carbamate (carbaryl) and organophosphate (chlorpyrifos) in A. mellifera L. honey bees via feeding bioassay [79]. A. cerana generally exhibits greater sensitivity to insecticides (imidacloprid and clothianidin) compared to A. mellifera [80].…”

Muscarinic acetylcholine receptor activation synergizes the knockdown and toxicity of GABA‐gated chloride channel insecticides

“…Insecticides play an indispensable role in pest management programs that improve the standard of living 4 and provides the support that is needed to feed a growing population. However, the widespread and improper application of insecticides expedites the development of resistance that limits the arsenal of pest control options that jeopardizes the effectiveness of pest control programs, 5 but also impacts the environment and non‐target organisms, including pollinators 6 . There is a need to identify novel or underutilized targets for developing alternative pest management strategies.…”

“…However, the widespread and improper application of insecticides expedites the development of resistance that limits the arsenal of pest control options that jeopardizes the effectiveness of pest control programs, 5 but also impacts the environment and non-target organisms, including pollinators. 6 There is a need to identify novel or underutilized targets for developing alternative pest management strategies. This could include insecticidal mixtures that enhance currently available active ingredients, 7 a strategy that has previously been used to control Helicoverpa armigera, 8 Culex quinquefasciatus, 9 Tuta absoluta, 10 Helicoverpa zea, Spodoptera frugiperda, Agrotis ipsilon, 11 and Spodoptera litura.…”