The problem is the amount of focused manpower needed to properly carry out the pollination process. That’s where commercially produced bees come in: commercial bumblebee hives, for example, are designed exclusively for crop pollination. Not just for tomatoes, but other crops as well: peppers; cukes; squash; cane-, straw-, blue- and cranberries; and many other crops in need of primary or supplemental pollinators.
Growers should use bumblebees shortly after the first flowers appear. Normal greenhouse conditions (without the normal greenhouse sprays) can support the hive, though excessively high temperatures may hamper activity. Cool temperatures, on the other hand, may slow activity, but don’t completely halt it. That’s the nice thing about bumblebees versus honeybees, they can fly in cool weather, down to 41°F, even in the rain and on windy or cloudy days, visiting flowers, bruising them (a scouting sign of activity), doing their thing. Honeybees won’t even come out of their hive in those conditions, and temperatures have to be at least 50°F. Consequently, Bombus spp. are a viable option for outdoor use in addition to greenhouse applications. They’re bigger, faster, better and more versatile.
Please bear in mind, though, not the bees, but the actual hives, must be sheltered from the elements if used outdoors. A half-sheet of plywood will do. And indoors, the hives must be placed above the ground, in a vibration-free (from fans, etc.) place where they will be sheltered from irrigation water, traffic, etc., yet open from all frontal angles of approach. Placed on 2 cinder blocks on end, perhaps, and in such a way that ants cannot access it (by applying a sticky trap compound to the blocks). By the way, don’t open the little doors until the bees inside settle down. They can be agitated from all the handling and might respond to your handling aggressively, so wait at least one hour.
In fact, anytime while using bees, it should be noted that they can sting. If you’re hypersensitive to stings, do not go anywhere near these hives. It is, in fact, best to not even enter a greenhouse or field while the bees are being used. The non-allergic individual should go about his or her business as usual, but occasional stings can occur. Give the bee hive a wide berth when possible. Additionally, try not to make wild movements around the hive, as this may evoke aggression. Bright colored clothing may spark curiosity from the bees, but should not provoke them as long as you keep your composure. In a nutshell, bumblebees should be given due respect. They are not domesticated or trained, just laboratory reared.
The hive is constructed of cardboard and plastic and comes with its own food source. The hive is completely self-contained.
Bombus impatiens can be used in all states except Oregon (where they are prohibited), Washington (where they can be used in screened structures only), and in California (where growers need a state-issued permit). Get more info about the latter at CA Dept. of Food and Ag. The California State Permit in question is Form 66-026.
Most growers have success with bumblebee hives, with the huge labor-savings and improved fruit-set, at least nobody’s complaining too loudly.
Release Rates for Bombus impatiens
|Comments||Greenhouse crop volume should be considered as it is done when figuring for other biocontrol agents.|
|Class A||This hive treats 10-15,000 square feet for 12-14 weeks.|
|Class B||This hive treats 5-10,000 square feet for 10-12 weeks.|
|Class C||This hive treats up to 5,000 square feet for 4-5 weeks|
|Quads||This large outdoor hive treats up to 2 acres on its own or up to 4 acres supplementary.|