scholarly journals Food Shortage Amplifies Negative Sublethal Impacts of Low-Level Exposure to the Neonicotinoid Insecticide Imidacloprid on Stream Mayfly Nymphs

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2142
Author(s):  
Julia G. Hunn ◽  
Samuel J. Macaulay ◽  
Christoph D. Matthaei
Keyword(s):  
Food Availability ◽  
Sublethal Effects ◽  
Interactive Effects ◽  
Starvation Period ◽  
Stream Invertebrates ◽  
Freshwater Organisms ◽  
Multiple Stressor ◽  
Neonicotinoid Insecticide ◽  
Mesocosm Experiments ◽  
Dependent Processes

Interactions of pesticides with biotic or anthropogenic stressors affecting stream invertebrates are still poorly understood. In a three-factor laboratory experiment, we investigated effects of the neonicotinoid imidacloprid, food availability, and population density on the New Zealand mayfly Deleatidium spp. (Leptophlebiidae). Larval mayflies (10 or 20 individuals) were exposed to environmentally realistic concentrations of imidacloprid (controls, 0.97 and 2.67 μg L−1) for nine days following five days during which individuals were either starved or fed with stream algae. Imidacloprid exposure had severe lethal and sublethal effects on Deleatidium, with effects of the lower concentration occurring later in the experiment. The starvation period had delayed interactive effects, with prior starvation amplifying imidacloprid-induced increases in mayfly impairment (inability to swim or right themselves) and immobility (no signs of movement besides twitching appendages). Few studies have investigated interactions with other stressors that may worsen neonicotinoid impacts on non-target freshwater organisms, and experiments manipulating food availability or density-dependent processes are especially rare. Therefore, we encourage longer-term multiple-stressor experiments that build on our study, including mesocosm experiments involving realistic stream food webs.

Sublethal Effects of the Neonicotinoid Insecticide Thiamethoxam on the Transcriptome of the Honey Bees (Hymenoptera: Apidae)

2017 ◽  
Vol 110 (6) ◽  
pp. 2283-2289 ◽  
Author(s):  
Teng-Fei Shi ◽  
Yu-Fei Wang ◽  
Fang Liu ◽  
Lei Qi ◽  
Lin-Sheng Yu
Keyword(s):  
Honey Bees ◽  
Sublethal Effects ◽  
Neonicotinoid Insecticide

scholarly journals Weather and food availability additively affect reproductive output in an expanding raptor population

Oecologia ◽  
2021 ◽  
Author(s):  
Melanie Nägeli ◽  
Patrick Scherler ◽  
Stephanie Witczak ◽  
Benedetta Catitti ◽  
Adrian Aebischer ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Food Availability ◽  
Reproductive Output ◽  
Weather Conditions ◽  
Interactive Effects ◽  
Food Supplementation ◽  
Nestling Development ◽  
Trade Offs ◽  
Adverse Weather ◽  
Expanding Population

AbstractThe joint effects of interacting environmental factors on key demographic parameters can exacerbate or mitigate the separate factors’ effects on population dynamics. Given ongoing changes in climate and land use, assessing interactions between weather and food availability on reproductive performance is crucial to understand and forecast population dynamics. By conducting a feeding experiment in 4 years with different weather conditions, we were able to disentangle the effects of weather, food availability and their interactions on reproductive parameters in an expanding population of the red kite (Milvus milvus), a conservation-relevant raptor known to be supported by anthropogenic feeding. Brood loss occurred mainly during the incubation phase, and was associated with rainfall and low food availability. In contrast, brood loss during the nestling phase occurred mostly due to low temperatures. Survival of last-hatched nestlings and nestling development was enhanced by food supplementation and reduced by adverse weather conditions. However, we found no support for interactive effects of weather and food availability, suggesting that these factors affect reproduction of red kites additively. The results not only suggest that food-weather interactions are prevented by parental life-history trade-offs, but that food availability and weather conditions are crucial separate determinants of reproductive output, and thus population productivity. Overall, our results suggest that the observed increase in spring temperatures and enhanced anthropogenic food resources have contributed to the elevational expansion and the growth of the study population during the last decades.

scholarly journals Habitat ephemerality affects the evolution of contrasting growth strategies and cannibalism in anuran larvae

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12172
Author(s):  
Dogeun Oh ◽  
Yongsu Kim ◽  
Sohee Yoo ◽  
Changku Kang
Keyword(s):  
Natural Selection ◽  
Food Availability ◽  
Common Garden ◽  
Larval Period ◽  
Interactive Effects ◽  
Ephemeral Streams ◽  
Growth Strategies ◽  
Abiotic Stressors ◽  
Lower Body Weight ◽  
Indirect Fitness

Ephemeral streams are challenging environments for tadpoles; thus, adaptive features that increase the survival of these larvae should be favored by natural selection. In this study, we compared the adaptive growth strategies of Bombina orientalis (the oriental fire-bellied toad) tadpoles from ephemeral streams with those of such tadpoles from non-ephemeral streams. Using a common garden experiment, we tested the interactive effects of location (ephemeral vs. non-ephemeral), food availability, and growing density on larval period, weight at metamorphosis, and cannibalism. We found that tadpoles from ephemeral streams underwent a shorter larval period compared with those from non-ephemeral streams but that this difference was contingent on food availability. The observed faster growth is likely to be an adaptive response because tadpoles in ephemeral streams experience more biotic/abiotic stressors, such as desiccation risk and limited resources, compared with those in non-ephemeral streams, with their earlier metamorphosis potentially resulting in survival benefits. As a trade-off for their faster growth, tadpoles from ephemeral streams generally had a lower body weight at metamorphosis compared with those from non-ephemeral streams. We also found lower cannibalism rates among tadpoles from ephemeral streams, which can be attributed to the indirect fitness costs of cannibalizing their kin. Our study demonstrates how ephemeral habitats have affected the evolutionary change in cannibalistic behaviors in anurans and provides additional evidence that natural selection has mediated the evolution of growth strategies of tadpoles in ephemeral streams.

scholarly journals Interaction between Varroa destructor and imidacloprid reduces flight capacity of honeybees

2015 ◽  
Vol 282 (1820) ◽  
pp. 20151738 ◽  
Author(s):  
Lisa J. Blanken ◽  
Frank van Langevelde ◽  
Coby van Dooremalen
Keyword(s):  
Varroa Destructor ◽  
Lethal Dose ◽  
Interactive Effects ◽  
Colony Losses ◽  
Cascading Effects ◽  
Flight Capacity ◽  
Colony Collapse ◽  
Flight Mills ◽  
Neonicotinoid Insecticide ◽  
Parasitic Mite

Current high losses of honeybees seriously threaten crop pollination. Whereas parasite exposure is acknowledged as an important cause of these losses, the role of insecticides is controversial. Parasites and neonicotinoid insecticides reduce homing success of foragers (e.g. by reduced orientation), but it is unknown whether they negatively affect flight capacity. We investigated how exposing colonies to the parasitic mite Varroa destructor and the neonicotinoid insecticide imidacloprid affect flight capacity of foragers. Flight distance, time and speed of foragers were measured in flight mills to assess the relative and interactive effects of high V. destructor load and a field-realistic, chronic sub-lethal dose of imidacloprid. Foragers from colonies exposed to high levels of V. destructor flew shorter distances, with a larger effect when also exposed to imidacloprid. Bee body mass partly explained our results as bees were heavier when exposed to these stressors, possibly due to an earlier onset of foraging. Our findings contribute to understanding of interacting stressors that can explain colony losses. Reduced flight capacity decreases the food-collecting ability of honeybees and may hamper the use of precocious foraging as a coping mechanism during colony (nutritional) stress. Ineffective coping mechanisms may lead to destructive cascading effects and subsequent colony collapse.

Lethal and sublethal effects of a novel cis-nitromethylene neonicotinoid insecticide, cycloxaprid, on Bemisia tabaci

2016 ◽  
Vol 83 ◽  
pp. 15-19 ◽  
Author(s):  
Ran Wang ◽  
Huixin Zheng ◽  
Cheng Qu ◽  
Zehua Wang ◽  
Zhiqiang Kong ◽  
...  
Keyword(s):  
Bemisia Tabaci ◽  
Sublethal Effects ◽  
Neonicotinoid Insecticide

scholarly journals Population decline in a ground-nesting solitary squash bee (Eucera pruinosa) following exposure to a neonicotinoid insecticide treated crop (Cucurbita pepo)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
D. Susan Willis Chan ◽  
Nigel E. Raine
Keyword(s):  
Cucurbita Pepo ◽  
Pesticide Exposure ◽  
Sublethal Effects ◽  
Population Decline ◽  
Foliar Spray ◽  
Risk Assessments ◽  
Seed Coating ◽  
Pollination Services ◽  
Neonicotinoid Insecticide ◽  
Ground Nesting

AbstractInsect pollinators are threatened by multiple environmental stressors, including pesticide exposure. Despite being important pollinators, solitary ground-nesting bees are inadequately represented by pesticide risk assessments reliant almost exclusively on honeybee ecotoxicology. Here we evaluate the effects of realistic exposure via squash crops treated with systemic insecticides (Admire-imidacloprid soil application, FarMore FI400-thiamethoxam seed-coating, or Coragen-chlorantraniliprole foliar spray) for a ground-nesting bee species (Hoary squash bee, Eucera pruinosa) in a 3-year semi-field experiment. Hoary squash bees provide essential pollination services to pumpkin and squash crops and commonly nest within cropping areas increasing their risk of pesticide exposure from soil, nectar, and pollen. When exposed to a crop treated at planting with soil-applied imidacloprid, these bees initiated 85% fewer nests, left 5.3 times more pollen unharvested, and produced 89% fewer offspring than untreated controls. No measurable impacts on bees from exposure to squash treated with thiamethoxam as a seed-coating or foliage sprayed with chlorantraniliprole were found. Our results demonstrate important sublethal effects of field-realistic exposure to a soil-applied neonicotinoid (imidacloprid) on bee behaviour and reproductive success. Soil must be considered a potential route of pesticide exposure in risk assessments, and restrictions on soil-applied insecticides may be justified, to mitigate impacts on ground-nesting solitary bee populations and the crop pollination services they provide.

scholarly journals Testing the multiple stressor hypothesis: chlorothalonil exposure alters transmission potential of a bumblebee pathogen but not individual host health

2021 ◽  
Vol 288 (1947) ◽  
Author(s):  
Austin C. Calhoun ◽  
Audrey E. Harrod ◽  
Toby A. Bassingthwaite ◽  
Ben M. Sadd
Keyword(s):  
Positive Association ◽  
Interactive Effects ◽  
Negative Effects ◽  
Pollination Services ◽  
Transmission Potential ◽  
Multiple Stressor ◽  
Pathogen Dynamics ◽  
Nosema Bombi ◽  
Individual Host ◽  
Host Health

Numerous threats are putting pollinator health and essential ecosystem pollination services in jeopardy. Although individual threats are widely studied, their co-occurrence may exacerbate negative effects, as posited by the multiple stressor hypothesis. A prominent branch of this hypothesis concerns pesticide–pathogen co-exposure. A landscape analysis demonstrated a positive association between local chlorothalonil fungicide use and microsporidian pathogen ( Nosema bombi ) prevalence in declining bumblebee species ( Bombus spp.), suggesting an interaction deserving further investigation. We tested the multiple stressor hypothesis with field-realistic chlorothalonil and N. bombi exposures in worker-produced B. impatiens microcolonies. Chlorothalonil was not avoided in preference assays, setting the stage for pesticide–pathogen co-exposure. However, contrary to the multiple stressor hypothesis, co-exposure did not affect survival. Bees showed surprising tolerance to Nosema infection, which was also unaffected by chlorothalonil exposure. However, previously fungicide-exposed infected bees carried more transmission-ready spores. Our use of a non-declining bumblebee and potential higher chlorothalonil exposures under some scenarios could mean stronger individual or interactive effects in certain field settings. Yet, our results alone suggest consequences of pesticide co-exposure for pathogen dynamics in host communities. This underlies the importance of considering both within- and between-host processes when addressing the multiple stressor hypothesis in relation to pathogens.

Multiple-stressor effects on stream invertebrates: DNA barcoding reveals contrasting responses of cryptic mayfly species

2016 ◽  
Vol 61 ◽  
pp. 159-169 ◽  
Author(s):  
Jan N. Macher ◽  
Romana K. Salis ◽  
Katie S. Blakemore ◽  
Ralph Tollrian ◽  
Christoph D. Matthaei ◽  
...  
Keyword(s):  
Dna Barcoding ◽  
Stream Invertebrates ◽  
Multiple Stressor
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