Insecticides

Devastating impact of river pollution on mayflies, killing about 80% of all eggs

Clouds of emerging mayflies were once a regular sight on English summer evenings and they are a key part of the food chain that supports fish, birds and mammals. But modest levels of pollution found in many English rivers are having a devastating impact on mayflies, new research suggests, killing about 80% of all eggs. In October, a study found that the abundance of flying insects has plunged by 75% in 25 years, prompting warnings that the world is “on course for ecological Armageddon”, with profound impacts on human society.

Clothianidin induces anxiety-related behavior in male mice

Experimental studies have revealed that neonicotinoids pose potential risks for the nervous systems of non-target species, but the brain regions responsible for their behavioral effects remain incompletely understood. This study aimed to assess the neurobehavioral effects of clothianidin (CTD), a later neonicotinoid developed in 2001 and widely used worldwide, and to explore the target regions of neonicotinoids in the mammalian brain.

Systemic pesticide concerns extend beyond the bees

In the summer of 2010, Henk Tennekes from Experimental Toxicology Services Nederland at Zutphen warned that the accumulation of neonicotinoids in the environment would not only decimate useful insects but also have a knock-on effect on other species, including birds (Curr. Biol. (2011) 21, R137–R139). At the time, Tennekes did not find much support for his views and went on to publish his warnings as a book — The Systemic Insecticides: A Disaster in the Making.

The insect world is falling apart

Though unnoticed by the world at large, a whole giant ecosystem is collapsing. It has taken us a lot of time to understand this catastrophe for two reasons: one cultural, one scientific. Firstly, we generally do not care for insects (bees and butterflies excepted). In the population as a whole there is little sympathy for the fate of the chitin-skeletoned little things that creep and crawl; our default reaction is a shudder. Fewer bugs in the world? Many would cheer.

Vleermuizen staan bloot aan neonicotinoïde insecticiden

De ingekorven vleermuis (Myotis emarginatus) heeft vaste vliegroutes en foerageert een substantieel deel van de tijd in veestallen maar jaagt ook vlak boven het bladerdak van bomen. De soort jaagt op spinnen en op kleine insecten, voornamelijk tweevleugeligen als vliegen en muggen, maar ook op nachtvlinders, rupsen, gaasvliegen en kevers. Op drie kraamkamerlocaties in Limburg (Lilbosch, Maria Hoop en Eijsden) zijn in de periode 2013-2015 dode individuen en mest verzameld.

Immunosuppression in Honeybee Queens by Thiacloprid and Clothianidin

Queen health is crucial to colony survival of honeybees, since reproduction and colony growth rely solely on the queen. Queen failure is considered a relevant cause of colony losses, yet few data exist concerning effects of environmental stressors on queens. Here we demonstrate for the first time that exposure to field-realistic concentrations of neonicotinoid pesticides can severely affect the immunocompetence of queens of western honeybees (Apis mellifera L.).

Pesticide exposure can reduce the ability of amphibians to resist parasite infections

Across host–parasite systems, there is evidence that pesticide exposure increases parasite loads and mortality following infection. However, whether these effects are driven by reductions in host resistance to infection or slower rates of parasite clearance is often unclear. Using controlled laboratory experiments, we examined the ability of larval northern leopard frogs (Lithobates pipiens) and American toads (Anaxyrus americanus) to resist and clear trematode (Echinoparyphium sp.) infections following exposure to the insecticide carbaryl.

Combined neonicotinoid pesticide and parasite stress alter honeybee queens’ physiology and survival

Honeybee colony survival strongly relies on the queen to overcome worker losses exposed to combined stressors like pesticides and parasites. Queen’s capacity to withstand these stressors is however very little known. The effects of the common neonicotinoid pesticide imidacloprid in a chronic and sublethal exposure together with the wide distributed parasite Nosema ceranae have therefore been investigated on queen’s physiology and survivorship in laboratory and field conditions.

The neonicotinoids thiacloprid, imidacloprid, and clothianidin affect the immunocompetence of honey bees

A strong immune defense is vital for honey bee health and colony survival. This defense can be weakened by environmental factors that may render honey bees more vulnerable to parasites and pathogens. Honey bees are frequently exposed to neonicotinoid pesticides, which are being discussed as one of the stress factors that may lead to colony failure.

Umweltbundesamt will schärfere Zulassungsverfahren für Pflanzenschutzmittel

Die Zulassungsbehörden in Deutschland müssen die indirekten Folgen von Pflanzenschutzmitteln für die Artenvielfalt stärker berücksichtigen. Zu diesem Urteil kommen die Autoren eines am vergangenen Freitag vorgestellten Rechtsgutachtens, das vom Umweltbundesamt (UBA) in Auftrag gegeben wurde. Nach Angaben des Umweltbundesamtes entstehen solche Effekte beispielsweise, wenn Vögel keine Nahrung mehr auf Äckern finden, da Pflanzenschutzmittel unbeabsichtigt Insekten und andere Nahrung der Vögel töten.