Educational Guide

Science of Pollination

Honey bees are essential in the production of several fruit, vegetable, and legume seed crops grown in the Mid-Atlantic region. Lack of adequate pollination often results in low yields and small or misshapen fruits. Many growers underestimate their pollination needs. It is likely that yield and quality of some crops suffer every year from inadequate pollination. To date, no satisfactory substitute for bee pollination has been found for any major insect-pollinated crop. In the case of most crops, large numbers of bees must be present on the bloom to produce a commercial crop.

It is the act of collecting nectar and pollen that makes the honey bee such a great pollinator of agricultural crops. As the bee moves within the flower, the dusty pollen (located on the anthers or the male parts of the flower) will stick to the hairy legs and body of the bee. When the bee leaves one flower and flies to another of the same species, the pollen on its body will be brushed onto the female part (pistil) of the new flower. Placing the male pollen on the female pistil is called pollination. It will cause the flower to bear fruit. Bee-aided pollination greatly increases the yield of many crops that would have to rely on accidental pollination by the wind if there were no bees present. In this activity, you will learn about flowers and their structures.

Pollination as a business offers additional opportunities to make money from your bees. Beekeepers located where they can produce a crop of honey and also rent bees for crop pollination can build more security into their businesses, especially for those years when the honey crop fails.

Moving Bees

Beekeepers must recognize several possible risks and problems associated with moving bees for pollination. At least one day before moving colonies, secure hive bodies together with wide staples or plastic or metal bands. The best time to move colonies is around dusk, when most of the bees have returned to the hive and are no longer flying. Many beekeepers move their colonies during the night, arriving at their destination at daybreak. Waiting to move colonies until daybreak is less desirable because increasing light intensity and rising temperatures put additional stress on colonies. A cool, rainy day is also an appropriate time to move bees at any hour, so long as the bees are not flying.

The entrances of hives are normally closed with wire screen while bees are in transit. Entrance screens are about 4 inches wide and as long as the hive entrance. Before loading, smoke the hive entrances and push the loosely folded V-shaped entrance screens into place. Seal shut all other hive openings. Some beekeepers make long-distance moves without closing hive entrances. This approach is helpful during very hot weather and when not traveling through large cities. Colonies are loaded during the night, with the vehicle engine running. Vibrations Pollinationfrom the motor calm the bees after the colonies are placed on the truck. A better approach is to cover the entire load with netting or plastic screen. Some beekeepers use trailers to move bees. Some are even modified so that the bees can remain on the trailers year-round, making the moving of colonies possible without lifting the hives.

If you need to move colonies during hot weather, you must screen entrances and you will need additional ventilation to prevent suffocation. Top-moving screens that cover the entire colony and provide 2 to 3 inches of clustering space are ideal. These screens replace the regular hive cover. Cover an empty shallow super or similar wooden frame with window screen or 8-mesh/inch hardware cloth and place it on the hive with the screen side on top. Wetting the load down with water is also beneficial. Stack the hives on the truck so that all colonies are sufficiently ventilated. Place the hives as close together as possible to keep the load from shifting, and securely tie down all stacks of hives. Commercial beekeepers who specialize in moving colonies use migratory lids so they can stack hives tight against each other; they nail bottom boards in place and keep colonies on pallets— sometimes the pallet replaces the bottom board.

When to Move Bees on to the Crop

Taking colonies into the target crop for pollination at the correct time will greatly enhance pollination. If colonies sit too long in a crop before it starts to bloom, foragers may become locked in on other blooming plants, hindering maximum visits to the crop to be pollinated. Place colonies in the crop only after the flowers become attractive to bees. In some tree fruits, a 10 to 25 percent bloom is recommended. However, if primary blossoms produce the choice fruit, as in apples for example, bees should be present either at the start of bloom or when the king bloom on the south side of the tree starts to open.

When a colony is moved 2 or more miles, established flight patterns are broken. The field bees must again start to search for nectar and pollen and the colony spends a day or more establishing new flight patterns. A good supply of target crop bloom must be present when the bees begin searching for this new feeding area. During cool weather in early spring, take the bees into the orchard when about 10 to 20 percent of the blossoms are open and leave them there until petal fall. In warm, sunny weather, you can move bees in when 25 percent of the flowers are open and then remove them shortly after full bloom; although most beekeepers and growers prefer that colonies remain until the end of bloom. In actuality, one good pollinating day with plenty of bees and pollinizer bloom present is enough for setting a crop in most tree fruits. If bees in or near a crop are not working the target crop, moving them away and moving in other colonies from more than 2 miles away sometimes helps.