DIY: How to build a bumblebee hotel
Just as it seems the whole land is resting for the winter, we should be turning our thoughts to how best to care for the humble bumblebee.
These lovely, hairy insects are no stranger to many of our gardens, and their essential role in pollinating our orchards and crops means we should do everything in our power to entice them into our gardens with clever planting and a great nesting site.
But before we even consider building a site – or a nest, for that matter – it pays to be conversant with the insect's life cycle in both space and time. The middle of winter, when everybody is more or less dormant, is paradoxically a good time to start the familiarisation.
Fertilised queens are those huge, bumbling flying machines we so love and cherish. They are really the only life stage that exists in winter, given that all the (usually smaller) workers and drones (males) have kicked the cyclical bucket by autumn.
These females hide themselves under leaf litter, in old mouse holes, or simply under compost in open bins. Anywhere there's a cosy cavity, away from the most severe frosts will do. Indeed, on the warmer winter's days a queen may be seen flying about, gathering nectar or pollen from the odd flower in the garden.
These remarkable creatures have the ability to warm up their muscles to 35°C, which allows them to travel to all the nutritious products on offer, and reach a resource that few other insects can access at this time of the year.
When the first hint of spring is in the air, the queen goes on the lookout for a more permanent position for the beginnings of her nest. Once again, it has to be in a floriferous area, with plenty of shelter and preferably easily accessible by air.
A hole at the base of a tree would do nicely; a small gap in between a few stacked bricks or a pile of jute bags would also be really cool real estate. As long as there's no overheating by direct sunshine in summer, no flooding during downpours or excess shade, frost or cold wind, a bumblebee queen will be happy.
The small nest area will be provisioned with a "honey pot" created from wax, which is extruded from between her abdominal body segments. Collected pollen is then mixed with the nectar within that pot and sculpted into pollen balls, which form the larder for the queen's first batch of larvae. The creation of these larval foods is why it's so important to have early spring-flowering plant species in your garden.
As soon as the first offspring (which become the workers) have dried their wings, the queen goes into semi-retirement, concentrating mostly on egg-laying and light domestic duties, I suppose. The workers will then set about gathering the fodder and directing the brooding efforts around the nest.
That nest will grow week by week and the numbers of inhabitants increase accordingly. Isn't it lovely to see the buzzing traffic in your garden?
To encourage these insects to set up shop, you can easily create a wooden bumblebee nest box. Here's our step by step guide.
1.5m x 250mm x 25mm dressed, treated pine
1.8m x 45mm x 19mm dressed, treated pine
small piece of 22mm-wide pipe
plastic lid at least 250mm x 190mm
wire gauze, 2 x 40mm x 40mm pieces
8g x 45mm galvanised countersink screws
8g x 30mm galvanised countersink screws
3 x 15mm galvanised screws
countersink drill bit
22mm spade drill bit
18mm spade drill bit
saw, drill, sandpaper, wood glue, staple gun, paint
From the 250mm x 25mm dressed, treated pine cut 2 lengths x 250mm (sides); 2 x 150mm (ends); 1 x 290mm (roof); 1 x 250mm x 190mm (bottom)
From the 45mm x 19mm dressed, treated pine cut 2 x 290mm lengths (roof eaves); 2 x 192mm (roof eaves); 2 x 60mm (entry step & back panel); 2 x 160mm (feet)
Note: Take your own measurements before cutting these lengths, because dressed timber is measured before being
dressed. For example, our 250mm x 25mm dressed, treated pine (as indicated on the docket) actually measured 230mm wide.
Add bumblebee nesting materials such as dry moss or horsehair stuffing before you screw the plastic viewing lid on top.
STEP BY STEP INSTRUCTIONS
1. Take the two side panels and bottom panel and pre-drill screw holes, then countersink holes with a countersink bit.
2. On the end panels, drill pilot holes into ends. Apply glue. Using 45mm screws, fix sides and bottom to panels to make a box.
3. Pre-drill screw holes in roof panel and countersink. Drill pilot holes in the eaves, then glue and screw into place.
4. Drill an entry hole on one side of box just up from bottom, using 22mm spade bit. Drill a 22mm hole on entry back panel.
5. Screw together entry step and back. Insert pipe then push through hole in box. Screw landing into place with 30mm screws.
6. Drill ventilation holes in ends of box just below eaves, using 1.8mm spade bit. Screw feet to bottom of box using 30mm screws.
7. Cut plastic viewing lid to fit top of box. Drill 3 screw holes on one end of plastic only. Drill pilot holes in box and fix with 15mm screws.
8. Paint the outside and staple wire gauze over ventilation holes to prevent ants. The wooden roof sits on top to keep it warm and dark.
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- NZ Gardener