Honeybees - Part Two

As we learned in the first part of this series, in New Zealand as in the rest of the world, honeybee numbers are dwindling at an alarming rate, and this is of concern because honeybees are hugely important as pollinators of plants.

Honeybees are under threat

It's not really known why numbers are dwindling, but it could be a combination of parasitic (varroa) mites, lack of flowers and pesticide poisoning.  The varroa mite in particular is having a devastating effect as it has now spread throughout the country apart from the southernmost tip, and it seems likely that feral bees will be wiped out within a year or two.  Only well-managed hives are likely to survive the onslaught of the disease.

We need bees

In New Zealand, bees earn about $3 billion of the GDP as a result of intensive pollination of horticultural and specialty agricultural crops.  In addition there is a huge indirect contribution through the pollination of clover, sown as a nitrogen regeneration source for the land we farm. This benefit flows on to our meat export industry through livestock production and sales.  Export earnings alone total approximately $35 million annually.

We can all help

We can all help honeybees by planting bee-friendly species where we can.

• Species like crack willow and Peking willow, flowering currant, kowhai and rosemary are good sources of both nectar and pollen.
• Peach, nectarine and ornamental cherry trees and gorse (yes, gorse!) are good sources of pollen.
• Tree lucerne and five finger are good sources of nectar.

Care with use of pesticides is needed - don't spray flowering crops when bees are foraging and keep use of sprays to a minimum.

Lifecycle of bees

Honeybees, Apis mellifera, are fascinating little creatures.  They have a very short life - less than 6 weeks - and during that time the workers are very active, flying up to 800 km with very little rest.  Most of this effort goes into making honey, but even so each little worker only manages the equivalent of half a teaspoon of honey in her lifetime!

Honeybees live in complex, socially structured colonies with around 50,000 workers and hundreds of male drones, but only one queen.

• The workers develop from fertilised eggs.
• They build the wax cells in the hive where the larvae are reared.
• They work ceaselessly to collect pollen, nectar and sap which they store in the hive.
• The workers attend to the basic chores of the hive and tend to the eggs and larvae laid by the queen.
• They 'tell' each other where to find the best flowers by doing a stylised dance at the hive entrance.
• They navigate using the position of the sun, on cloudy days using polarised light waves.
• They can only work when the temperature is over 10 degrees C.
• When it is cold they cluster together inside the hive to keep warm and they live on their honey supply.
• When it's hot the bees gather at the entrance and fan cool air into the hive to keep it at a comfortable temperature.
• The queen's role is to lay up to 2000 eggs a day during the summer season.
• She may leave the hive during spring or summer and set up a new hive with the workers who follow her. This is a "swarm".
• The drones compete to mate with the queen when she goes on this 'mating flight' then they die.
• Before the queen leaves the hive, she lays a special egg.  The larva that hatches is fed royal jelly produced by nurse bees and it develops into a new queen.  The queen lives on royal jelly for the rest of her life.
• The young queen destroys other potential queens while they're still at the pupa stage.
• Drones develop from unfertilised eggs and their main role is to fertilise virgin queen bees when they swarm.

The history of honeybees in New Zealand

Honeybees were introduced in 1839, with others introduced in 1840 and 1842.  In 1880 Italian bees were imported from the United States

The honey industry

In 1995, there were over 5,000 members of the National Beekeepers Association, which is run entirely from a levy on every hive in New Zealand ($1.61 per hive in1995).  There are almost 300,000 bee hives in New Zealand, but their numbers are declining.

The bee industry currently produces a total saleable crop of around 8,000 tonnes of honey each year.

• The most popular honey, white clover honey, has a light colour and mild flavour.
• Honey from rata, rewarewa and pohutukawa is sought after and more expensive.
• Honey from manuka is the most expensive at $9000 a tonne.

In years when bees are not able to make enough honey to see them through the winter, they may need to be fed by their beekeepers.

As well as producing honey for sale, bees produce much more including:

• Hives of bees.
• Honey by-products such as beeswax, pollen, health products such as vitamins and skin moisturisers.
• Queen bees, particularly for Canada and Korea (largely because our bee species are acclaimed as the healthiest in the world).
• And even NZ bee semen!

Honeybees and wasps

There are between two and three thousand species of wasps in New Zealand, most of them native, but only about 28 native and 13 introduced bee species.  The species we recognise most often are the German wasp, common wasp, paper wasp, honeybee and bumblebee.

Bee species come in all shapes and sizes, and it can be very difficult to distinguish some species from wasps!  Most bee and wasp species are small and many are tiny.

Most bee and wasp species are solitary, but at least three bee species including the honeybee have a social structure.

Native bees pollinate many native plants and they are important pollinators in horticulture.  The most common native bees look like honeybees but they are mostly very small (5-12 mm long) and black.  They dig nest holes in the ground.

Bees and wasps can look very similar.  How can you tell them apart?

• Wasps are thinner with smooth hairless bodies and slender legs.
• Bees are generally hairy, more robust than wasps and with flat legs for gathering pollen.  Their hairy bodies and flat legs are ideal for holding on to the pollen as they carry it from one area to another.
• Wasps can be aggressive.
• Bees are mild-mannered.
• Wasps eat many of the same foods we do, for example in garbage.  They are also predators, and while adults may occasionally feed on nectar or pollen, they and their larvae feed on insects, arthropods, flies and even caterpillars.
• Bees are totally vegetarian, they gather nectar and pollen from flowers and don't scavenge garbage.

Everyone on the farm should be able to distinguish between wasps and bees and anyone attempting to control wasps with insecticides should try to ensure that bees will not contact the poisons.

Bumblebees

Four species of bumblebee were imported as queen bees from England late in the nineteenth century to improve pollination of red clovers, which honeybees cannot pollinate because they have shorter tongues.

In NZ bumblebees are now being artificially reared, because their numbers are perilously low.  Ironically, plans are afoot to export bumblebees from NZ to the UK where they originally came from, because in the UK bumblebees are now extinct.

Bumblebees have a social structure and build nests in hollow cavities each year with about 200 workers in each colony.  In autumn the nest degenerates and the bees die, but new queens leave the nest to over-winter in cavities in the soil, ready to start their own nests in spring.