Wednesday, May 31, 2017

GMO Crops and Bees

New technologies are, rightfully, viewed with skepticism. One of our blog readers asks, “Is there any effect of transgenic crops on bees?” The use of genetic engineering involves transgenic material, a portion of one plant or animal, being inserted into another organism. The resulting plant or animal is described as being a “genetically modified organism,” or GMO. In the case of crops, the purpose of the transfer of genetic material is to produce a new crop with desired traits. A number of crops are regularly produced using transgenic technologies include corn, rice, soybean, cotton, and rapeseed. Some GMO crops, especially soybean, cotton, and canola (rapeseed), are regularly foraged by honey bees. Careful study continues to determine any effect that the planting of GMO crops that are food sources for honey bees will have on the health of the bees and the safety of the honey that the bees produce.

Currently, there are two principal uses of GMO technology used to produce agricultural crops. The first employs Bt (Bacillus thuringiensis) genes to produce a toxin in crop plants as a means of controlling insect pests. The second GMO technology in common usage is designed to control crop weeds. The herbicide glyphosate, known as Roundup, is in widespread use to control broad-leaf weeds and grasses. Genetically modified corn, canola, alfalfa, sugar beets, and cotton are resistant to glyphosate. The herbicide can be sprayed over the genetically modified, glyphosate-resistant crop plants and weeds, killing only the weeds. Neither Bt toxin nor glyphosate-resistant GMO technologies appear to be harmful to honey bees and other pollinators, nor do they contaminate honey. The use of glyphosate-resistant technology does have a negative effect on bees and insect pollinators when it destroys the weedy field margins that previously provided food and habitat for these insects. Today’s photo shows a GMO soybean field. Glyphosate herbicide killed the weeds and grass in the crop area and along the field margin, leaving soybean plants growing without competition.

Friday, May 19, 2017

Reversing the Bee Hive

Throughout the spring, healthy honey bee colonies rapidly increase in population. This occurs as flowering plants are making nectar and pollen significantly more abundant. Both are collected by foraging worker bees and welcomed into the hive. The pollen is stored in close proximity to the brood nest where the queen is laying eggs and the workers are feeding and tending to the developing brood. The nectar, which will be converted into honey, is stored in the hive area outside the brood nest beyond the surrounding pollen. However, if there is not enough free honeycomb cells available, the bees will store the nectar in the brood nest. When this happens, beekeepers describe the hive as being “honey bound.” A serious hive problem results because the queen is left with no place to lay eggs. Prolific queens need at least 1500 empty cells per day to lay the eqqs necessary to sustain the colony’s population. As the brood nest becomes congested with nectar and honey, the colony starts making preparations for swarming. It is important for beekeepers to check for brood nest congestion and to take corrective action.

Honey bees cluster together and generate heat during cold weather. It is common for the cluster of bees to gradually move upward in the hive over the winter months. In the spring, beekeepers need to determine the position of the brood nest and the cluster of bees. Some colonies will move back down into the lower portion of the hive during the spring, but it is common for bees to remain in the upper half of the hive. This has the effect of the bees living in a hive of one-half its normal volume. Reversing the position of the hive bodies gives the colony greater capacity in the brood nest, providing cells for the queen to lay eggs. This is an important beekeeping measure in swarm suppression. Today’s photo: a queen bee on a honey-bound frame with capped honey, liquid honey, and pupa-stage brood.

Saturday, May 6, 2017

Swarm Season

Healthy honey bee colonies swarm. Swarming is the honey bee’s way of reproducing on a colony-wide basis. Honey bees typically swarm in the spring, and this season has been exceptionally “swarmy.” The Mid-South experienced a warm winter, and springtime weather arrived early. Warm weather and frequent rains brought plenty of wildflowers into bloom. Mild weather allowed the bees to take advantage of red maple and other early-blooming plants. Early-season pollen flows stimulated the queens to rapidly increase egg-laying in late winter and spring. Unless beekeepers expand the capacity of their hives in the spring by rearranging hive bodies and adding extra boxes of frames, hives tend to get congested with honey. Brood nest congestion, where the queen doesn’t have adequate numbers of cells to lay eggs, leads to swarming.

Beekeepers don’t like for their hives to swarm. The smaller resulting colonies don’t have enough bees to produce a surplus of honey. The effect of a hive’s swarming is that this year’s honey crop just flew away! However, beekeepers are often able to capture swarms of bees where they rest, often on a tree limb or structure like the wall of a house, before they fly away to a permanent nesting location. These captured bee colonies make for good replacements of winter hive losses. Captured swarms are particularly useful because the bees are especially capable of drawing out beeswax honeycombs. If the beekeeper feeds sugar syrup to a newly hived swarm, it will rapidly fill the hive with honeycombs. Captured bee swarms are a source of genetic diversity, and they may bring in desirable traits. Beekeepers should evaluate their swarm colonies and replace the queen if the bees show undesirable traits, such as excessive defensiveness. Today’s photo: young workers make orientation flights at the entrance to a hive of swarming bees captured in early April. Swarm catching can be quite exciting. A beekeeping friend, an avid outdoorsman, proclaims that he would rather catch a swarm of bees than a five-pound bass!