Fipronil promotes motor and behavioral changes in honey bees (Apis mellifera) and affects the development of colonies exposed to sublethal doses

Abstract

Bees play a crucial role in pollination and generate honey and other hive products; therefore, their worldwide decline is cause for concern. New broad-spectrum systemic insecticides such as fipronil can harm bees and their use has been discussed as a potential threat to bees' survival. In the present study, the authors evaluate the in vitro toxicity of fipronil and note behavioral and motor activity changes in Africanized adult Apis mellifera that ingest or come into contact with lethal or sublethal doses of fipronil. The effects of sublethal doses on brood viability, population growth, behavior, and the expression of the defensin 1 gene in adult bees were studied in colonies fed with contaminated sugar syrup (8 µg fipronil L(-1) ). Fipronil is highly toxic to bees triggering agitation, seizures, tremors, and paralysis. Bees that are exposed to a lethal or sublethal doses showed reduced motor activity. The number of eggs that hatched, the area occupied by worker eggs, and the number of larvae and pupae that developed were reduced, adult bees showed lethargy, and colonies were abandoned when they were exposed to sublethal doses of fipronil. No change was seen in the bees' expression of defensin 1. The authors conclude that fipronil is highly toxic to honey bees and even sublethal doses may negatively affect the development and maintenance of colonies.

An update of the Worldwide Integrated Assessment (WIA) on systemic insecticides. Part 2: impacts on organisms and ecosystems

“…Concentrations of several brain proteins involved in detoxification, glycolysis, and cell growth were altered, possibly leading to memory and learning impairment and to a reduced life span. Zaluski et al (2015) also used Africanized honeybees in their study about effects of fipronil on colony development and bee motoric control and behavior. Treated adult bees (1/500th of the LD50) bees showed reduced motor activity and became lethargic, while treated colonies showed a reduction in egg laying and larval numbers.…”

Protective Effect of Nigella Sativa (Black Caraway (Oil on Oral Dichlorvos Induced Hematological, Renal and Nonspecific Immune System Toxicity in Wistar Rats

“…Harmful chemicals in the environment and their burden on health have become an issue of great importance in recent decades [1], causing toxicity to a variety of biota and human life [2].…”

Evaluation of Motor Changes and Toxicity of Insecticides Fipronil and Imidacloprid in Africanized Honey Bees (Hymenoptera: Apidae)

“…Residual levels of systemic insecticides can contaminate the resources collected by bees for long periods and can be stored in nests (Chauzat et al, 2006;Mullin et al, 2010;OrantesBermejo et al, 2010). In the nest, the contaminated resources are used to feed larvae and adults, generating physiological and behavioral changes in bees and compromising the productivity and colony maintenance (Orantes-Bermejo et al, 2010;Zaluski et al, 2015).…”

“…The LD 50 value is determined based on laboratory tests corresponding to the dose capable of causing the death of 50% of the population over a period of 24 or 48 hours. Currently, the tests to regularize the use of pesticides do not regard the damages that bee exposure to doses below the LD 50 (sublethal doses) can cause to honey bees individually and to the entire colony (Zaluski et al, 2015;Sanchez-Bayo & Goka, 2016).…”

“…The poly-hybrid bees resulting from these crossings expressed high defensive behavior, have good resistance to diseases, and are excellent pollinators (Pereira & ChaudNetto, 2005). Some studies performed with Africanized bees demonstrate that fipronil is highly toxic to newly emerged bees and to foragers (Zaluski et al, 2015); whereas studies performed by de Almeida Rossi et al (2013) demonstrate that imidacloprid is highly toxic to newly emerged bees.…”