Bumble bees and apple pollination.
Apples trees are rarely self fertile and apples need pollen to be transferred from the stamen to ovule, to form. Hence apples trees are reliant on insects to pollinate them. The commonest used in NZ is the honey bee but they are not optimal in several ways. They form long lived hives and therefore forage for both pollen and nectar. Individual bees tend to become specialised in one or the other, The nectar gathers or lateral gatherers come in from the side and therefore avoid or miss the pollen and so are poor pollinators. Only the apical gatherers collect the pollen. Bumble bees on the other hand are very efficient generalists. They collect both pollen and nectar and are apical feeders with a longer proboscis or tongue. They are more vigorous, hairy and larger so are more efficient in depositing pollen on the ovules.
Due to an unique efficient body heating system fuelled by intermittently decoupling their wings from the thoracic muscles and oscillating them many times a second , they can operate at temperatures down to close to freezing whereas honey bees rarely venture out below 13C. These are not warm blooded mammals and this comes at a big energy cost. Whilst it is often thought that humming birds have the highest metabolic rate of all animals, the metabolic rate of bumblebees is 75% higher than a humming bird's. They need this remarkable feat to carry their large bumbling bodies through the cold air. They will also work from daylight to dark in rainy weather and continue working in temperatures just above freezing
Bumblebees can carry up to 90% of their body weight in food. The level of activity and energy required to fly is so great they are only ever 40 minutes away from starvation! They can reach ground speeds up to 54 km per hour and are great navigators, remembering specific landmarks to help navigate back to the nest. Bumblebees are social insects and can live in nests of up to 400 bees. Each nest has a queen and will last for only one year. we have bumble bees in NZ. These were brought out initially from 1885 to pollinate clover for the agricultural lands. The native bees wasps and honey bees all having too short a proboscis to achieve that. It was expensive to continue to import clover seeds.
The word ‘bumblebee’ is a compound of ‘bumble’ +’bee’ –‘bumble’ meaning to hum, buzz, drone or move ineptly or flounderingly, (the bumble is the noise oscillating the uncoupled wings make, see above). The bee cannot buzz and fly at the same time or it would crash. It alternates hundreds of time a second!
The generic name Bombus assigned by Pierre Latreille in 1802, is derived from the latin word for a buzzing or humming sound.
At TeePee cider we usually import 2 new hives from a commercial grower each Spring. These will die out over several months but not before new Queens are made which will over winter and form new nests in tree holes or old burrows in the ground. These seem to be able to fend off the ubiquitous small black ant that attack the bee houses, hence we place a 'moat around the bee house', ants don't swim!
And now there are bumble bees in the area each Spring before the courier brings the new colonies.
To read more about Bumbles in NZ go to here