English

English

A Review of Sub-lethal Neonicotinoid Insecticides Exposure and Effects on Pollinators

Beekeepers around the world have been reporting the ongoing weakening of honeybee health and subsequently the increasing colony losses since 1990. However, it was not until the abrupt emergence of colony collapse disorder (CCD) in the 2000s that has raised the concern of losing this important perennial pollinator. In this report, we provide a summary of the sub-lethal effects of pesticides, in particular of neonicotinoids, on pollinators’ health from papers published in peer-review journals.

Eastern monarch butterfly population plunges below extinction threshold

The yearly count of monarch butterflies overwintering in Mexico, released today, shows a decrease of 53% from last year's count and is well below the threshold at which government scientists predict the migration could collapse.

Scientists estimate that 6 hectares—about 15 acres—is the extinction threshold for the migratory butterflies' survival in North America. The latest count, conducted by World Wildlife Fund Mexico, found overwintering monarchs occupying just 2.83 hectares, or 7 acres.

Neonicotinoids can negatively affect immunocompetence in the red mason bee leading to impaired disease resistance capacity

Solitary bees are frequently exposed to pesticides, which are considered as one of the main stress factors that may lead to population declines. A strong immune defence is vital for the fitness of bees. However, the immune system can be weakened by environmental factors that may render bees more vulnerable to parasites and pathogens.

Costa Rica caterpillar decline spells trouble for ecosystems

Scientists have uncovered alarming declines in caterpillar diversity and their parasites across 22 years of monitoring in a protected forest in Costa Rica. Scientists studied the Lepidoptera order of moths and butterflies by collecting all externally feeding caterpillars — those found on leaves and not the inner tissue of a plant. They also collected the parasites that live off their caterpillar hosts, known as parasitoids, including wasps (order Hymenoptera) and flies (order Diptera).

Engineered symbionts to safeguard honeybee health and their pollination services: A response

Leonard et al. (1) presented an interesting approach to limit the impact of pathogens on honeybees by stimulating immunity via engineered symbionts. The urgency to safeguard pollinator services is undoubted. Massive declines in bees, insects in general, pose major concerns for ecosystem stability and food production. However, we see potential pitfalls in such technology driven approaches. Leonard et al. attribute high honeybee colony mortality to the parasitic mite Varroa destructor via synergistic interactions with RNA viruses. However, Varroa is only a significant concern for honeybees.

Moth numbers have declined by 31% across Great Britain between 1969 and 2016

Suggestions of an imminent ‘insectageddon’ have received a great deal of attention recently. A study using more than 24 million individual insects caught over a period of almost half a century has revealed a greater understanding of their populations - and whether they really are being driven to an impending extinction. In this new report, data were collected by the Rothamsted Insect Survey from 137 insect traps sited across Great Britain between 1969 and 2016.

Neonicotinoids damage the brains of baby bees, new research finds

In a new study, scientists examined exactly how bumblebees are affected by pesticides by scanning bumble bee brains and testing their learning abilities.They found that baby bees can feel the effects of the food contaminated by pesticides brought back by worker bees into the colony, making them poorer at performing tasks later in life.