White-nose syndrome in American bats is likely to be caused by exposure to pesticides

Dutch researchers have detected a cocktail of 14 different pesticides (fungicides, herbicides, insecticides) in bats. In dead individuals and manure classical insecticides such as DDT and permethrin were found, but the animals were also exposed to the neonicotinoids imidacloprid and thiamethoxam, the herbicides mecoprop and nicosulfuron, and the fungicides iprodione and propiconazole. Pesticides such as imidacloprid, propoxur, thiamethoxam, nicosulfuron and iprodione had not previously been reported to be present in bats. Permethrin - a wood preservative - was found in relatively high concentrations. The observed concentrations may not be acutely lethal to bats, but chronic effects including immune suppression, which would explain the endemic white nose syndrome that killed millions of bats in North America, can not be ruled out.

Wood beams used in hibernation are a likely source of exposure. The wooden beams of three places of bat residence contained 19 different pesticides, nine of which were found in dead bats and bat droppings. The wood is preserved with these pesticides. It is likely that insecticides originated from contaminated insect food.

Source: Blik op nieuws, 15-12-2016

Henk Tennekes

do, 15/12/2016 - 15:28

Outbreaks of infectious diseases in honey bees, fish, amphibians, bats and birds in the past two decades have coincided with the increasing use of systemic insecticides, notably the neonicotinoids and fipronil. A link between insecticides and such diseases is hypothesised. Firstly, the disease outbreaks started in countries and regions where systemic insecticides were used for the first time, and later they spread to other countries. Secondly, recent evidence of immune suppression in bees and fish caused by neonicotinoids has provided an important clue to understand the sub-lethal impact of these insecticides not only on these organisms, but probably on other wildlife affected by emerging infectious diseases. While this is occurring, environmental authorities in developed countries ignore the calls of apiarists (who are most affected) and do not target neonicotinoids in their regular monitoring schedules. Equally, scientists looking for answers to the problem are unaware of the new threat that systemic insecticides have introduced in terrestrial and aquatic ecosystems.

Rosemary Mason, Henk A Tennekes, Francisco Sanchez-Bayo, Palle Uhd Jepsen (2012) Immune suppression by neonicotinoid insecticides at the root of global wildlife declines. Journal of Environmental Immunology and Toxicology 2013; 1:3-12. DOI: 10.7178/jeit.1 (attached).