Tents for bees are in place on a farmer's field on Range Road 63. The tents provide ideal habitat for leafcutter bees that in turn work very hard pollinating crops.--NEWS PHOTO GILLIAN SLADE
gslade@medicinehatnews.com@MHNGillianSlade
The tent camping season has begun for leafcutter bees.
As farmers’ crops flourish with recent rains, preparations are underway to ensure there are plenty of bees to fertilize those crops and that’s where those little triangular “tents” come in.
The tents provide the necessary conditions for leafcutter bees to work very hard pollinating female canola flowers to produce hybrid seed.
Canola grown for its commercial value as a crop is self-pollinating. but if you are growing it for seed you need leafcutter bees, a farmer told the News.
There are male and female canola seeds which are planted in stripes, and bees are needed to move pollen from the male plant flowers onto the female plant flowers. Generally there are 25 per cent male plants to 75 per cent female plants in a field.
The seed that comes from that female plant will have higher yield potential.
Agronomists monitor the canola growth to determine the optimum time for placing bees in the canola field to start pollinating, said Brady Glimsdale agronomist with Pioneer Hi-Bred Ltd., Lethbridge, told the News in an interview for a previous story. Once the first canola flowers start appearing, a judgment call is made on the day to have the bee-renting company arrive with the bees.
Leafcutter bees are supplied by companies such as Van der Stoel Pollinating Ltd., located at Enchant in the municipal district of Taber. They have been supplying leafcutter bees for about 20 years.
If you use a combination of leafcutter bees and honeybees the odds of success are even better.
Honeybees are most active when temperatures are cooler than 25 C. Leafcutter bees on the other hand like it hot and are more active when it is hot. They do not like getting wet though. The tents provide protection from rain and water during irrigation.
Each tent provides protection for a number of rectangular shaped boxes with numerous pencil-sized channels that are about three or four inches deep. The leafcutters fill each channel with bits of leaf, honey and about six eggs.
Those cells are kept in cool storage over winter and are then incubated in preparation for going back into canola fields. The temperatures used, and even the number of leafcutters supplied per acre of canola, are trade secrets.
When they arrive on site, some leafcutters will have already hatched, and others will be very close to hatching. A formula is used to determine how many leafcutter bees are required, and they are ordered by the gallon of larvae.
According to online information, one alfalfa leafcutter bee can do the job of 20 honey bees, and based on observation in a greenhouse, 150 leafcutter bees can pollinate what it would take 3,000 honeybees to do.
While leafcutter bee shelters are placed throughout the crop it is often possible to see honeybee boxes on a corner of a field. Honeybees will travel further than the leafcutters. Having a combination of honey and leafcutter bees covers all bases, plus irrigation of the crop, for maximum yield.
Male canola plants flower for fewer weeks than the female plants do. To mitigate that, with timing advised by agronomists, farmers trim the tops of some rows of male plants causing additional flowers to branch out from the sides about five or six days later. This extends the pollination season.
The seed harvested from these crops is sold to companies such as Pioneer Hi-Bred Ltd.
