Information Bulletin No.72

Stingless Bees Developed for Pollinating Fruit Trees

February 13, 1996

Honeybees are often used in the pollination of such fruit-bearing trees as apples and pears, but they pose a hazard to the fruit grower, who risk being stung.
To eliminate this annoyance, researchers at the National Institute of Animal Industry of the Ministry of Agriculture, Forestry and Fisheries, has succeeded in producing bees that cannot sting, and it is hoped that they will resolve a longstanding sore point for fruit growers.

Pollen Carrier
Pollination is an important part of a fruit-grower's task, and many farmers still perform the task manually, climbing ladders and crouching to pollinate each flower. To lighten this load, some have begun harnessing honeybees as pollinators. As the bees fly around in search of nectar, they carry pollen from one flower to another. Those who are not used to handling the bees, though, are frequently stung, and experienced beekeepers must be enlisted to release and recapture the bees.
At the National Institute of Animal Industry, an attempt was made to produce honeybees that would not sting by exposing them to gamma waves. It was found in that if bee larvae were exposed to 30 grays of radiation just before becoming pupae, 97% of the bees born had deformed stingers. The typical stinger consists of two narrow needles encased in a sheath, but in the mutant variety, the two needles were separated from the sheath, destroying their ability to sting.
Of the 18 queen larvae that were exposed to radiation in the same way, 16 were born as no stingers.

Controlling Reproduction
The new varieties of both queen and worker bee showed no difference other than in the stinger, and they otherwise appeared to behave normally. This led researchers to believe that the exposure to radiation had caused a genetic mutation in the bees. Researchers are now working to determine how many larvae of stinger-less queens will have the same trait and to establish a process by which the trait can be genetically transmitted.
One concern is the impact the stinger-less bees will have on the ecosystem if they breed with naturally occurring varieties. The mixing of genetic strains can be prevented, researchers, believe, by simply utilizing worker bees for pollination purposes, since they have no reproductive capabilities and thus pose no threat that they will breed with bees in the wild.

(The above article, edited by Japan Echo Inc., is based on domestic Japanese news sources. It is offered for reference purposes and does not necessarily represent the policy or views of the Japanese Government.)