Bumblebees

Much attention has been given to the plight of bees because of their importance as pollinators of major crops. But there is growing evidence that butterflies and moths – many of which have suffered dramatic declines in recent years – play an important role as specialist pollinators of some of our favourite wild flowers. A Swedish study recorded pollen on the bodies of three-quarters of butterfly species examined with some individuals carrying up to 350 grains.

Bees and butterflies are experiencing widespread population decline, creating public concern in recent years. Data collected in Germany suggest that it’s not just bees and butterflies at risk: insect populations overall have plummeted by more than 75 percent since 1989. Scientists have known about the population decline for several years. However, they didn’t know how many species were declining, and they didn’t expect it to be happening so fast.

Ecologists at the University of Stirling in Scotland have found that neonicotinoids reduce the strength and duration of a bumblebee’s buzz. Their study was published this week in the journal Scientific Reports. Buzzing is more important than you might think. The vibrations of a bee's wingbeat help it shake pollen from flowers and onto its body. This pollen then gets deposited on the next flower the bee visits, resulting in pollination. Less buzzing equals less pollination, and reduces the bees' ability to forage for themselves.

Getreide, Kartoffeln, Tomaten – viele Nutzpflanzen sind, nicht nur für einen hohen Ertrag, auf die Bestäubung durch Insekten angewiesen. Dass Pestizide das Bestäubungsverhalten von Hummeln beeinträchtigen, haben Forscherinnen und Forscher des Karlsruher Instituts für Technologie (KIT) und der University of Stirling herausgefunden. Ihre Ergebnisse stellen sie in der Fachzeitschrift Scientific Reports vor.

The UK will back a total ban on insect-harming pesticides in fields across Europe, the environment secretary, Michael Gove, has revealed. The decision reverses the government’s previous position and is justified by recent new evidence showing neonicotinoids have contaminated the whole landscape and cause damage to colonies of bees. It also follows the revelation that 75% of all flying insects have disappeared in Germany and probably much further afield, a discovery Gove said had shocked him.

A previous study reported by Cresswell et al. (2014) claimed a differential behavioural resilience between spring or summer honey bees (Apis mellifera) and bumble bees (Bombus terrestris) after exposure to syrup contaminated with 125 µg L−1 imidacloprid for 8 days. The authors of that study based their assertion on the lack of body residues and toxic effects in honey bees, whereas bumble bees showed body residues of imidacloprid and impaired locomotion during the exposure. We reproduced the experiments of Cresswell et al.

Paulina Mena, an associate professor of biology, has been studying bees for over a decade, an obsession which stems from her undergraduate experiences at Universidad Catolica de Valparaiso, Chile. “I did my undergraduate degree in Chile, and decided to do bee stuff because Chile is a hot spot for bees. Bees like deserts; that is where they have diversified a bunch,” Mena said.

Neonicotinoid pesticides pose severe threats to ecosystems worldwide, according to new information contained in an update to the world’s most comprehensive scientific review of the ecological impacts of systemic pesticides. The Task Force on Systemic Pesticides (TFSP) released the second edition of its Worldwide Integrated Assessment of the Effects of Systemic Pesticides on Biodiversity and Ecosystems today in Ottawa, Canada. It synthesizes more than 500 studies since 2014, including some industry-sponsored studies.