A global problem: Vanishing bees

In response to recent declines and collapses in honey bee populations worldwide, the United Nations has launched a $27 million project to protect key pollinators for global food security and biodiversity. The five-year Global Pollinators Project will be coordinated by the United Nations Food and Agriculture Organisation (FAO) and implemented through the United Nations Environment Programme (UNEP) and the Global Environment Facility (GEF)

The Guardian UK: Honeybee deaths reaching crisis point

USDA: Colony Collapse Disorder

NZ Herald: Mystery bee illness threatens kiwifruit industry

We asked bee scientists to discuss the importance of pollinators for crop production and our environment.

Mark Goodwin, Honeybee Research Institute, HortResearch said:

“There are a wide range of reasons for the decline. For honey bees the major reason are diseases and pathogens. Varroa is the largest threat but several new diseases have been identified in bees recently. These have jumped species as varroa did 60 years ago. The most notable is Nosema ceranae, a stomach parasite, and Israelite Acute Paralysis virus. This latter is the probably the cause of the colony collapse disorder seen in the USA. Insecticides are becoming a increasing threat to honey bees and other pollinators. Land clearances and monoculture are negatives for solitary bees as they destroy nesting sites and don’t provide food year round. To conserve bees, we need to find solutions to their diseases, and a sustainable method of controlling the varroa mite.”

Brad Howlett, pollination entomologist, Crop & Food Research said:

“Many food plants, such as kiwifruit, tomatoes, capsicums, pip and stone fruit, require insect-mediated pollination for viable fruit or seed set. This pollination service contributes at least $2 B annually to New Zealand’s economy and directly underpins $12.5 B of export revenue from the horticulture, arable, pastoral and beekeeping sectors.

“Insect-mediated pollination service is most obviously delivered in New Zealand by Apis mellifera, the European honeybee. This service is under substantial pressure in New Zealand from the Varroa mite, and worldwide from both Varroa and Colony Collapse Disorder.

“At Crop & Food Research, we have been determining both the role and contribution of native pollinators to crop pollination with a focus on seed crops. We have found that native bees, flies and other insects all play significant roles in crop pollination. We are now seeking to understand how we could manage native bee species so that if honeybee pollinators become unreliable or non-existent then this country can maintain its current levels of insect-dependant food production. This is a particular challenge, as native bees are not social insects like the European honey bee and cannot be managed via artificial hives. Also the substantial changes in land use in New Zealand is resulting in loss of habitat for these important insects.

“Approximately one in three mouthfuls of our food, including the majority of high-value crops that contribute to healthy diets (most fruits, vegetables, and nuts which provide most of the vitamins), are from insect-pollinated crops. Crop & Food Pollination scientists are focused on ensuring that healthy insect-pollinated foods remain on our plates, despite the world-wide pressure on the bee populations.”

Barry Donovan, entomologist, author of Fauna of New Zealand 57 – Apoidea – a revision of all known species of NZ bees, said:

“The continuing presence of bees in good numbers is vital for the sustainability of both wild environments and human civilization. This is because of their `keystone’ role as pollinators of both flowering naturally-occurring native biota and crops grown for food.

“But whether the 20,000 species of bees known world-wide are under real threat is difficult to determine. “Take New Zealand native bees as an example. My 2007 revision of bees of New Zealand showed that of 27 species which occur only in New Zealand, at least 4 are extremely rare — known from only one or a few specimens. However, whether the species were more abundant before the advent of humans in the country is unknown. Widespread destruction of native forests that did not yield pollen and nectar for bees, and replacement with introduced flowering plants seems to have actually increased food supplies for many species of native bees.

“But there is no doubt that the Western Honey Bee Apis mellifera is under severe threat. Acarine and varroa mites are killing many hives throughout most of the world (including New Zealand for varroa), and during the last two summers a new condition known as Colony Collapse Disorder has been implicated in the deaths of perhaps up to a third of all hives in the United States. Also some insecticides such as neonicotinoides, and perhaps a new disease called Nosema ceranae which originated from the Eastern Honey Bee Apis cerana (as did varroa) are causing mortalities in many countries. Because honey bees are the main pollinators of most crops needing pollination, a reduction in honey bees has major adverse implications for food supplies.

“To determine the survival status of any particular species of bee, surveys of numbers foraging on flowers, the geographic range over which the bees are found, and populations of nests sites is needed each year for several years. If a species is determined to be under threat, immediate steps must be taken to eliminate insecticide exposure, increase the particular flora foraged upon, and to protect and expand nest sites.

“Only by conserving and enhancing all species of bees can we protect our own wellbeing, and that of the planet as a whole.”

To talk to these and other scientists contact the Science Media Centre on 04 499 5476 or smc@sciencemediacentre.co.nz.