Bees and red light

Kwame S Aidoo, Department of Entomology & Wildlife, School of Biological Sciences, University of Cape Coast, Ghana

Keywords: Apis mellifera adansonii, Ghana, honey collection, honey bee management, West Africa:

Introduction

In most parts of the tropics and especially Africa, beekeeping activities that involve opening a bee hive are carried out at night. High temperatures during the day make the bees active and sometimes difficult to handle. Worker bees become less active during the cooler times of the day, because like all other insects bees are cold-blooded. Most beekeepers therefore attend to their colonies early in the morning or late in the evening when temperatures are cooler and the bees are relatively calm, less defensive and easier to manipulate. Torch light plays an important part during colony inspection and honey harvesting.

One drawback in the use of torches is that bees (and most insects) are attracted to lights at night. When torch light is used, worker bees are observed moving in high numbers to sections of the hive where the light is shown. There is always conflict between the use of torch light and use of the smoker. A beekeeper applies smoke to move bees away but the bees keep coming back to the illuminated area. In some cases angry bees will sting the gloves of the person carrying the torch light.

A possible solution to this problem is based on the fact that bees do not see red light. The use of red light during night-time colony management could be the answer.

Materials and method

Two identical torches were obtained. The first produced ordinary white light, the second was modified to emit red light by cutting out a round piece of red polyethylene sheet and fixing it on the glass of the torch. Two sheets of black cloth measuring 50 cm 2 were obtained. A strong colony of the West African honey bee Apis mellifera adansonii was selected for the test. At 1900 hours when it was dark the colony was disturbed by tapping the side of the hive close to the entrance. One of the pieces of cloth was hung about 20 cm from the entrance and the white light was shone upon it. The number of bees attracted to the spotlight in the cloth in a five minute period was counted and recorded. The experiment was repeated on the same colony using red light from the modified torch. This experiment was replicated five times.

Torches modified to emit red light facilitate night-time colony management

PHOTO © KWAME AIDOO

Results

Table 1 shows the number of worker bees of Apis mellifera adansonii attracted to white and red lights within a period of five minutes when their colony was disturbed at night. Analysis of the results indicates high significant difference between the two treatments. Honey bee workers were attracted to white light more than red light when disturbed in darkness.

* Table 1. The original article has a table showing these results which is not available on this mobile friendly version.

Field trial

A hunter’s torch light was bought and modified as described above to produce red light. This was used during honey harvesting in the night. The result was that the bees were relatively calm, moved away from the beekeeper’s smoke and did not attack the face of the beekeeper wearing the modified hunter’s light on his forehead. The colony was not so defensive because it was disturbed less and consequently harvesting went smoothly.

Recommendation

Beekeepers in different regions of the tropics should first test the reaction of their bees to red light. If results are similar to this experiment they can adopt the use of red torch light during colony management at night.

Kwame Aidoo is Bf D’s Correspondent in Ghana and works as a lecturer and teacher.