Effects of neonicotinoids and fipronil on non-target invertebrates

Abstract

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 (earthworms), 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. For terrestrial and aquatic invertebrate species, the known effects of neonicotinoid pesticides and fipronil are described ranging from organismal toxicology and behavioural effects to population-level effects. For earthworms, freshwater and marine species, the relation of findings to regulatory risk assessment is described. Neonicotinoid insecticides exhibit very high toxicity to a wide range of invertebrates, particularly insects, and field-realistic exposure is likely to result in both lethal and a broad range of important sublethal impacts. There is a major knowledge gap regarding impacts on the grand majority of invertebrates, many of which perform essential roles enabling healthy ecosystem functioning. The data on the few non-target species on which field tests have been performed are limited by major flaws in the outdated test protocols. Despite large knowledge gaps and uncertainties, enough knowledge exists to conclude that existing levels of pollution with neonicotinoids and fipronil resulting from presently authorized uses frequently exceed the lowest observed adverse effect concentrations and are thus likely to have large-scale and wide ranging negative biological and ecological impacts on a wide range of non-target invertebrates in terrestrial, aquatic, marine and benthic habitats.

Reconciling laboratory and field assessments of neonicotinoid toxicity to honeybees

“…adverse physiological or behavioural changes measurable at levels well below the 50% lethal dose (LD 50 ) currently used as a legal reference threshold for plant protection product approval. Neonicotinoids have been found to have sublethal effects on mobility, orientation, foraging and learning performances [6][7][8][9][10][11]. However, it is not clear whether these endpoints are reflected in a corresponding effect at field level [12].…”

Neonicotinoids: Systemic Insecticides and Systematic Failure

“…For example, a recent study published in BECT reported that 89% of the surface water samples collected from three agricultural regions in California contained imidacloprid, and 19% of the samples had imidacloprid concentrations that exceeded the USEPA risk threshold for aquatic life of 1.05 µg/L (Starner and Goh 2012). It has also been reported that the occurrence of neonicotinoids in surface water at environmentally relevant concentrations can negatively affect the physiology and survival rates of freshwater and marine animal species (Pisa et al 2015).…”

Pollinators and Global Food Security: the Need for Holistic Global Stewardship

“…In low dose, it disturbs flight behaviour, navigation, brood development and impairs individual and social grooming. Synergistic effects with other agrochemicals have been found Pisa et al 2015).…”

“…Increasing honeybee disorders, abnormally high winter colony losses, and reduced lifespan of honeybee queens has been observed over the past decades , Pisa et al 2015. So far, research points in the direction that no single cause explains the global increase in winter colony losses.…”

“…The EU followed in 2013 with a 2-year moratorium on the use of 3 neonicotinoids in crops attractive to bees (Maxim and Van der Sluijs 2013a;EASAC 2015; the ban is currently being reviewed by EFSA scientists). Fipronil, another systemic neurotoxic insecticide implied in bee disorders and also widely used, was considered for inclusion in the EU moratorium, but was instead subjected to restrictions (EFSA 2015;Pisa et al 2015).…”