A role far beyond that of just honey production.

Who would ever have thought something so small could inflict such fear and caution not only into the lives of small children but also that of grown adults? No matter how old you are you never want feel that unexpected stab of pain that you experience when stung by a bee. When I was little, they sent me running and screaming into the house to mum on more than one occasion and back then I swore black and blue that these little striped devils with wings ruined my childhood playing outside in the garden (we unfortunately lived on an orchard and every year without fail, dad brought bee hives in to pollinate the trees). However, now a little older and a little wiser I realised that in many ways the world would be lost without them.

With the advent of agriculture, a huge variety of plant species have been deliberately spread throughout the world for cultivation. Many of these plants require insect pollination to produce fruit and seed and to achieve this; bees have been introduced to ensure adequate crop pollination and high yields and returns. The honey bee (Apis mellifera L.) in particular is heavily relied on to pollinate a wide variety of crops and today plays a role far beyond that of just honey production. In New Zealand in particular bees are crucial to our primary sector as our countries dependence on horticulture and agriculture is dependant largely on pollination from this little gem. This is true for many other countries worldwide also. They essentially provide what is known as an ecosystem service which can be defined as resources and processes that are supplied by natural ecosystems that benefit humankind.

Since the 1830’s eight species of bee have been deliberately introduced into New Zealand. The honey bee was introduced primarily for honey production but has become the most important insect pollinator of seed, vegetable, fruit crops and pastures. Remaining species such as the bumble bee (Bombus terrestris), alkali bee (Nomia melanderi) and leaf cutting bee (Megachile rotundata) were introduced specifically to pollinate crops such as red clover or lucerne. However, consideration must be given to the potential impact that expanding populations of introduced bees could have on native and exotic flora and fauna. Also worthy of consideration is with the introduction and spread of things like the varroa mite in New Zealand since 2000, it highlights the importance of also considering other species for pollination should pollination services become unavailable through the loss of honey bees.

Research has shown that the more manageable bees such as bumble bee species and leaf cutting bees offer the greatest scope as alternative or supporting pollinators to the honey bee in New Zealand and it has been demonstrated that bumble bees will nest in man-made boxes under New Zealand conditions. It was however stated that further research is needed to determine the exact requirements needed to increase their numbers within agroecosystems. Currently the major limiting factors associated with using the leaf cutting bee for pollination on a wide scale include low bee numbers and its inactivity at temperatures less than 16°C or in windy conditions. This is somewhat problematic for some of New Zealand’s more temperate regions.

Unfortunately some introduced species have been seen to potentially pose a threat to some of New Zealand’s native pollinators which may have implications for the pollination of some of New Zealand’s unique plant life. For example the male of the wool-carder bee is an aggressive defender of territory and has been seen to kill other bee species. However since it was only introduced in 2005 its potential impact on New Zealand’s biota, the possible extent of its range and its potential abundance have not been clearly defined.

Currently there are no plans to introduce any new bee species into New Zealand although a number of species have been identified as potentially useful crop pollinators. However, research on utilising both native and introduced species more effectively within New Zealand’s agroecosystems may lead to more robust and integrated pollination systems that provide more efficient and predictable pollination services. Thus providing security in New Zealand’s agricultural and horticulture industries on a large scale.

This blog was based on an article by:

Howlett, B.G. & Donvan, B.J. (2010). A review of New Zealand’s deliberately introduced bee fauna: current status and potential impacts. New Zealand Entomologist, 33, 92-101.