Effects of neonicotinoids and fipronil on non-target invertebrates (2025)

WORLDWIDE INTEGRATED ASSESSMENT OF THE IMPACT OF SYSTEMIC PESTICIDES ON BIODIVERSITY AND ECOSYSTEMS Effects of neonicotinoids and fipronil on non-target invertebrates

We assessed the state of knowledge regarding the effects of large-scale pollution with neonicotinoid insecticides and fipronil on non-target invertebrate species of terrestrial, freshwater and marine environments. A large section of the assessment is dedicated to the state of knowledge on sublethal effects on honeybees (Apis mellifera) because this important pollinator is the most studied non-target invertebrate species. Lepidoptera (butterflies and moths), Lumbricidae (earth-worms), Apoidae sensu lato (bumblebees, solitary bees) and the section " other invertebrates " review available studies on the other terrestrial species. The sections on freshwater and marine species are rather short as little is known so far about the impact of neonicotinoid insecticides and fipronil on the diverse invertebrate fauna of these widely exposed habitats.

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

Environmental science and pollution research international, 2017

New information on the lethal and sublethal effects of neonicotinoids and fipronil on organisms is presented in this review, complementing the previous Worldwide Integrated Assessment (WIA) in 2015. The high toxicity of these systemic insecticides to invertebrates has been confirmed and expanded to include more species and compounds. Most of the recent research has focused on bees and the sublethal and ecological impacts these insecticides have on pollinators. Toxic effects on other invertebrate taxa also covered predatory and parasitoid natural enemies and aquatic arthropods. Little new information has been gathered on soil organisms. The impact on marine and coastal ecosystems is still largely uncharted. The chronic lethality of neonicotinoids to insects and crustaceans, and the strengthened evidence that these chemicals also impair the immune system and reproduction, highlights the dangers of this particular insecticidal class (neonicotinoids and fipronil), with the potential to ...

Chronic effects of an environmentally-relevant, short-term neonicotinoid insecticide pulse on four aquatic invertebrates

The Science of the total environment, 2018

Neonicotinoid insecticides used in agriculture can enter freshwater environments in pulses; that is, a short-term period of a higher concentration, followed by a period of a comparatively lower concentration. Non-target aquatic arthropods are exposed to these fluctuating concentrations of neonicotinoids. The present study investigated the potential latent effects of a single environmentally-relevant 24-h pulse of imidacloprid and thiamethoxam, in separate experiments, on the early life-stages of four aquatic arthropods (Hyalella azteca, Chironomus dilutus, Hexagenia spp., and Neocloeon triangulifer). At least three nominal pulse concentrations were tested for each neonicotinoid-species combination: 2.5, 5, and 10 μg L, which were based on environmental monitoring in Ontario, Canada. After exposure to the pulse, organisms were assessed for survival and immobilization. Surviving organisms were then moved into clean water for a chronic post-treatment period, where endpoints including s...

Physiological Effects of Neonicotinoid Insecticides on Non-Target Aquatic Animals—An Updated Review

International Journal of Molecular Sciences, 2021

In this paper, we review the effects of large-scale neonicotinoid contaminations in the aquatic environment on non-target aquatic invertebrate and vertebrate species. These aquatic species are the fauna widely exposed to environmental changes and chemical accumulation in bodies of water. Neonicotinoids are insecticides that target the nicotinic type acetylcholine receptors (nAChRs) in the central nervous systems (CNS) and are considered selective neurotoxins for insects. However, studies on their physiologic impacts and interactions with non-target species are limited. In researches dedicated to exploring physiologic and toxic outcomes of neonicotinoids, studies relating to the effects on vertebrate species represent a minority case compared to invertebrate species. For aquatic species, the known effects of neonicotinoids are described in the level of organismal, behavioral, genetic and physiologic toxicities. Toxicological studies were reported based on the environment of bodies of...

The Xerces Society for Invertebrate Conservation ARE NEONICOTINOIDS KILLING BEES? A Review of Research into the Effects of Neonicotinoid Insecticides on Bees, with Recommendations for Action

Neonicotinoid pesticides were first registered for use in the mid 1990s. Since then, these chemicals have become widely adopted for use on farm crops, ornamental landscape plants, and trees. Of the six neonicotinoids in common use on plants, the most widely used is imidacloprid. Neonicotinoids are systemic chemicals; they are absorbed by the plant and are transferred through the vascular system, making the plant itself toxic to insects. Recent concern has been expressed about the impact of this class of insecticides on pollinating insects such as honey bees. This concern is based on the fact that because they are absorbed into the plant, neonicotinoids can be present in pollen and nectar, making them toxic to pollinators that feed on these floral resources. The longlasting presence of neonicotinoids in plants, while useful from a pest management standpoint, makes it possible for these chemicals to harm pollinators even when the initial application is made outside of the bloom period...

Effects of neonicotinoid pesticide pollution of Dutch surface water on nontarget species abundance

A restatement of the natural science evidence base concerning neonicotinoid insecticides and insect pollinators

Proceedings. Biological sciences / The Royal Society, 2014

There is evidence that in Europe and North America many species of pollinators are in decline, both in abundance and distribution. Although there is a long list of potential causes of this decline, there is concern that neonicotinoid insecticides, in particular through their use as seed treatments are, at least in part, responsible. This paper describes a project that set out to summarize the natural science evidence base relevant to neonicotinoid insecticides and insect pollinators in as policy-neutral terms as possible. A series of evidence statements are listed and categorized according to the nature of the underlying information. The evidence summary forms the appendix to this paper and an annotated bibliography is provided in the electronic supplementary material.

Experimental evidence for neonicotinoid driven decline in aquatic emerging insects

Proceedings of the National Academy of Sciences, 2021

SignificanceSurvey data show a large-scale decline in insects. This global decline is often linked to human actions in intensive agricultural areas. To investigate whether this decline has a causal relationship with neonicotinoid insecticides, we performed an outdoor experiment with representative surface water concentrations of the neonicotinoid thiacloprid. We exposed naturally formed aquatic communities to increasing neonicotinoid concentrations and monitored insect emergence during a 3-mo period. We show that increasing neonicotinoid concentrations strongly decreased the abundance and biomass of five major insect orders that together comprised >99% of the 55,574 collected insects as well as the diversity of the most species-rich freshwater family, thus showing a causal relation between insect decline and neonicotinoids.

Impact of Neonicotinoids to Aquatic Invertebrates—In Vitro Studies on Mytilus galloprovincialis: A Review

Journal of Marine Science and Engineering, 2020

The use of pesticides in agriculture has always had a strong impact on environmental contamination. Since the 1990s, neonicotinoids have grown increasingly more popular, targeting specific receptors for insects, especially bees, which is why the use of some neonicotinoids has been banned. Much is known about the effects they have on insects, but very little about the effect they can have on non-target organisms. Several studies have shown how these neonicotinoids interact negatively with the normal physiology of aquatic organisms. For the genus Mytilus, even though the neonicotinoids did not show an interaction with specific receptors, a chronic and acute exposure to them causes damage. In these animals, a reduced production of byssus, alteration of the normal antioxidant systems and tissue damage have been found. Therefore, an analysis of the entire ecosystem in which the pollutant enters is of great importance in evaluating any possible alterations.

Impact of controlled neonicotinoid exposure on bumblebees in a realistic field setting

Journal of Applied Ecology, 2016

1. Pesticide exposure has been implicated as a contributor to insect pollinator declines. In social bees, which are crucial pollination service providers, the effect of low-level chronic exposure is typically non-lethal leading researchers to consider whether exposure induces sublethal effects on behaviour and whether such impairment can affect colony development. 2. Studies under laboratory conditions can control levels of pesticide exposure and elucidate causative effects, but are often criticized for being unrealistic. In contrast, field studies can monitor bee responses under a more realistic pesticide exposure landscape; yet typically such findings are limited to correlative results and can lack true controls or sufficient replication. We attempt to bridge this gap by exposing bumblebees to known amounts of pesticides when colonies are placed in the field. 3. Using 20 bumblebee colonies, we assess the consequences of exposure to the neonicotinoid clothianidin, provided in sucrose at a concentration of five parts per billion, over 5 weeks. We monitored foraging patterns and pollen collecting performance from 3282 bouts using either a non-invasive photographic assessment, or by extracting the pollen from returning for-agers. We also conducted a full colony census at the beginning and end of the experiment. 4. In contrast to studies on other neonicotinoids, showing clear impairment to foraging behaviours , we detected only subtle changes to patterns of foraging activity and pollen foraging during the course of the experiment. However, our colony census measures showed a more pronounced effect of exposure, with fewer adult workers and sexuals in treated colonies after 5 weeks. 5. Synthesis and applications. Pesticide-induced impairments on colony development and foraging could impact on the pollination service that bees provide. Therefore, our findings, that bees show subtle changes in foraging behaviour and reductions in colony size after exposure to a common pesticide, have important implications and help to inform the debate over whether the benefits of systemic pesticide application to flowering crops outweigh the costs. We propose that our methodology is an important advance to previous semi-field methods and should be considered when considering improvements to current ecotoxicological guidelines for pesticide risk assessment.