Neonicotinoid insecticides negatively affect performance measures of non‐target terrestrial arthropods: a meta‐analysis

Abstract

Neonicotinoid insecticides are currently the fastest-growing and most widely used insecticide class worldwide. Valued for their versatility in application, these insecticides may cause deleterious effects in a range of non-target (beneficial) arthropods. However, it remains unclear whether strong patterns exist in terms of their major effects, if broad measures of arthropod performance are negatively affected, or whether different functional groups are equally vulnerable. Here, we present a meta-analysis of 372 observations from 44 field and laboratory studies that describe neonicotinoid effects on 14 arthropod orders across five broad performance measures: abundance, behavior, condition, reproductive success, and survival. Across studies, neonicotinoids negatively affected all performance metrics evaluated; however, magnitude of the effects varied. Arthropod behavior and survival were the most negatively affected and abundance was the least negatively affected. Effects on arthropod functional groups were inconsistent. Pollinator condition, reproductive success, and survival were significantly lower in neonicotinoid treatments compared to untreated controls; whereas, neonicotinoid effects on detritivores were not significant. Although magnitude of arthropod response to neonicotinoids varied among performance measures and functional groups, we documented a consistent negative relationship between exposure to neonicotinoid insecticides in published studies and beneficial arthropod performance.

Ecological impacts of pesticide seed treatments on arthropod communities in a grain crop rotation

“…Arachnids are less susceptible to neonicotinoids than insects (Douglas & Tooker, 2016), and Easton and Goulson (2013) found that spiders were attracted to low doses of imidacloprid, which could explain the increased abundance of spiders. Another possibility is that sublethal impacts of the pesticides on insects made insect prey easier to capture (Main, Webb, Goyne, & Mengel, 2018), thereby improving resource availability and increasing spider abundance.…”

The Impact of Pesticides on Flower‐Visiting Insects: A Review with Regard to European Risk Assessment

“…Bumble bee colonies were exposed either by feeding them contaminated nectar but letting them forage without restriction or setting them up next to farmland to which pesticides had been applied. To summarize, in most studies neonicotinoid exposure led to reductions in worker, male, and queen offspring (colony growth), reduced individual growth, and skewed sex ratio (Gels et al 2002;Whitehorn et al 2012;Moffat et al 2015Moffat et al , 2016Rundlöf et al 2015;Ellis et al 2017;Main et al 2018). Impaired reproduction is caused not only by neonicotinoids but also by application of new substance classes such as sulfoximine insecticides (Siviter et al 2018).…”

Evaluating the ecological impacts of pesticide seed treatments on arthropod communities in a grain crop rotation

“…While we only measured abundance or activity density, neonicotinoids can negatively impact behavior, condition, reproductive success and survival of non-target arthropods (Main, Webb, Goyne, & Mengel, 2018). Examples of sublethal impacts on predatory taxa include reduced survival, longevity and oviposition in lady beetles (Papachristos & Milonas, 2008), delayed development and reduced fecundity and survival in minute pirate bugs (Gontijo et al, 2015), and paralysis, impaired walking, and increased grooming in ground beetles (Kunkel, Held, & Potter, 2001).…”