Researchers have found that long-term exposure to the neonicotinoid pesticide imidacloprid [wikipedia.org] can cause bats to forget flight paths and even lose the ability to catch insects [taipeitimes.com]. The pesticide can accumulate in the bats as a result of eating tainted insects:
Imidacloprid — a neonicotinoid pesticide that the US Environmental Protection Agency says can be harmful to bees — is a threat to the survival of bats, a research team said. The team, headed by National Taiwan Normal University professor of life sciences Wu Chung-hsin (吳忠信) found that bats feeding on imidacloprid-tainted insects were unable to fly along learned paths and often got lost while hunting. With Formosan leafnosed bats as their experimental subject, the team found that animals treated with a low dose of imidacloprid developed neural apopotosis — a process of programmed cell death — in the brain, Wu said.
Imidacloprid toxicity impairs spatial memory of echolocation bats through neural apoptosis in hippocampal CA1 and medial entorhinal cortex areas. [nih.gov] (DOI: 10.1097/WNR.0000000000000562) (DX [doi.org])
A species of bumblebee has been added to the U.S. Endangered Species List [wbur.org]. Canada designated the rusty patched bumblebee [wikipedia.org] as endangered in 2012:
The U.S. Fish and Wildlife Service has designated the rusty patched bumblebee an endangered species — the first such designation for a bumblebee and for a bee species in the continental U.S. The protected status, which goes into effect on Feb. 10, includes requirements for federal protections and the development of a recovery plan. It also means that states with habitats for this species are eligible for federal funds.
"Today's Endangered Species listing is the best—and probably last—hope for the recovery of the rusty patched bumble bee," NRDC Senior Attorney Rebecca Riley said in a statement [xerces.org] from the Xerces Society, which advocates for invertebrates. "Bumble bees are dying off, vanishing from our farms, gardens, and parks, where they were once found in great numbers." Large parts of the Eastern and Midwestern United States were once crawling with these bees, Bombus affinis, but the bees have suffered a dramatic decline in the last two decades due to habitat loss and degradation, along with pathogens and pesticides.
A UK study [nature.com] (open, DOI: 10.1038/ncomms12459) (DX [doi.org]) published in August linked neonicotinoids used on rapeseed crops to the decline of bumblebee species [nature.com].