Becoming a queen bee or worker bee is decided by the parasite flies

The strange thing is happening in lowland tropical forests in Panama and Costa Rica. A parasitic fly that affects the social behavior of bees that work at night helps determine which bee becomes a queen and which one becomes a worker bee.

Research results conducted by the University of Washington and the Smithsonian Tropical Research Institute are the first examples of the parasite's impact on the social behavior of a host. In the case of bees, fly larvae took food from immature bees.

The researchers found that the smaller bees born in the nest were controlled by their mothers. They tend to act like slave workers while larger ones often split and build new nests and become egg-laying queens. The bees that hatch from an egg cell and make a home for parasitic flies are usually smaller than the same bees, but are born from cells without flies . Parasitic flies may have stimulated the behavior of worker bees in some bees.

Tiny parasitic fly Chloropidae.(Photo: insect.cz)

Sean O'Donnell - associate professor of psychology at Washington University and co-author of the study published in the issue of the Journal of Insect Behavior - said: 'We often think bad things. parasites harm the health, survival or fertility of hosts. But in this case the parasite does not live inside the host but it can still get food from the host '.

'We think parasitic flies do not affect bee life. The mother of a baby bee can also benefit from having a bees, or worker bees, around to protect the nest to increase the bees' survival.

O'Donnell and his colleagues studied two closely related tropical bees, Megalopta genalis and Megalopta ecuadoria plus the tiny parasitic fly family called Chloropidae.

These two swarms of bees have been a powerful pollinator for the flowering plants at night. Female bees can nest alone or live in small colonies. Honeycomb is usually formed from 2 or 4 individuals including 1 queen and its descendants.

Queen bees and swarms of worker bees surrounded.(Photo: dkimages)

The observed behavior shows that honey bees do not reproduce as well as the bee protection group is much smaller than the queen in the nest, although the relative size of the bees varies according to each nest.In places where parasitic flies seem to adapt, they will affect the behavior of bees . The bees often nest in hollow tree branches or sticks hanging in the rainforest. The parasite flies will lay eggs right at the entrance to the nest. Some eggs fall randomly into the cells or rooms that the bees build. Each egg has larvae and pollen as food for the larvae. The cells will then be sealed, so if the box contains flies, the newly hatched flies will compete with bee larvae to get a limited supply of food.

O'Donnell said: 'There is a difference in the natural size of the bees, which is partly based on the food available in the egg cell. If one or more flies in a box reduces the supply of food, it may be a very important factor. The more parasitic flies in a box, the smaller the bee is born. The key here is the relative size of the body compared to the bees' hives. Larger bees will become queen bees because they are not restricted. '

Researchers have been feeding bees and flies in different plots. They counted up to 15 small flies in just one box. Some plots have no flies.

O'Donnel said: 'This study brings information against our intuition about the parasite's effect. It urges us to explore the complex ecological relationships between many different species. Parasitic activities can encourage socialism in some cases. In this case, the parasite promotes the social behavior of the bees'.