“There's no harvest without pollination,” says Henry Graham, research technician at the USDA in Weslaco, Texas. The effects of pollination on fruits such as melons, show in the increased weight and sugar content as well as in the increased number of fruit.
But it is estimated that the wild honeybee population in the Rio Grande Valley has decreased close to 90 percent over the past 10 years.
Yet from one to one and a half colonies of honeybees are needed to pollinate every acre of the fruits and vegetables grown in the area.
Since there are not enough honeybees in the wild, a producer must go to beekeepers to rent their colonies.
Beekeeping is expensive and management intensive. In order to have good, healthy colonies, beekeepers import European queens, sometimes thousands at a time, at an average of $10 apiece. A beekeeper spends thousands of dollars by providing supplements to build up the bees' strength.
A colony doesn't usually gain its full strength until the first of April, but producers often need their services by the middle of March, so the beekeepers must work intensively on that colony to have it ready by that time.
It is important for a farmer to deal with a reputable beekeeper who will provide him with strong colonies.
“Larger colonies collect more pollen, and are probably better pollinating units than smaller colonies,” says Graham. Colony size is determined by the strength of the brood rather than by the number of boxes in a colony.
A producer contracts with a beekeeper many months before he needs this service so that he will be assured that bees are available.
A signed contract specifies not only what the beekeeper will provide, such as the strength of the colonies to be delivered, but also what the farmer's duties are, such as providing the beekeeper with a pesticide application schedule.
Insects must be under control before the bees arrive, so that spraying will not occur while the bees are visiting. A grower has a responsibility in providing the best habitat for the bees he is renting.
Even pesticide drift from surrounding crops must be taken into consideration.
The beekeeper receives a map of the farmer's land after the first planting is complete, with the layout of the fields to be pollinated and surrounding crops that need to be considered for other effects on placement of the colonies.
Optimal placement is 500 meters from the farthest flower to be pollinated, or every quarter mile radius for a colony location.
Once the bees are in the field, they orient themselves, flying back and forth from the hive during the day. They get their job done in about 21 days, at which time the beekeeper retrieves his colonies, usually after dark, when all the bees have returned to the hive.
Since honeybees are such an integral part of the growing process, it is important to keep them healthy.
Dr. Bill Rubink, entomologist at USDA and four other scientists work in the Beneficial Insects Unit, headed by Dr. Walker Jones, at the USDA in Weslaco. Here they are concerned with the basic biology and management of honeybees, including pollination and chemical control of pests.
“There has been one problem after another for honeybees,” says Rubink. A parasitic mite, called Varroa, devastated more than half the colonies in about 10 years. Tracheal mites also did their damage.
The Weslaco laboratory works to develop pesticides to combat the mites. There are also bacterial and fungal diseases that attack the bees that the scientists are trying to eliminate.
Rubink and the other scientists work with local beekeepers to keep their colonies healthy.
Bill Vanderput of Magic Valley Honey and Pollination in Pharr is one of the few remaining commercial beekeepers in the Rio Grande Valley and keeps 3,000 hives for pollinating. Vanderput contracts with about 150 Valley farmers.
“Although the bees are in the field less than four weeks, our work goes on all year,” says Vanderput. “Keeping bees healthy is a full-time job.”