Date
Published: August 1, 2014
Source: Animal Behaviour
Summary: The act of pollination is a vital action required towards
maintaining the ecosystem through regulating the production of seeds from
flowers and plants. Without pollinators, the ecosystem would be vastly different
and potentially not function as effectively. It is essential for pollinators
such as honeybees to be protected from predators. Consequently, the
predation-prey relationship can play a major role in shaping an ecosystem.
Jianjun Li and his team of
researchers, investigated whether a species of Giant Asian Honeybees, Apis dorsata, is able to
eavesdrop and use its sense of smell to discover weaver ants, Oecophylla smaragdina, which
are known to attack and kill honeybees. Numerous organisms including weaver
ants are known to secrete pheromones, which are chemicals that organisms
secrete to communicate with other members of the same species. The researchers
hypothesized that the honeybees would be successful in detecting the ant
pheromones and would be able to evade the ants. This study was conducted in Kunming,
China.
This study was conducted in two
phases. The first phase involved creating two patches of five trees. One patch
was used a control, while the other was treated with five colonies of weaver
ants. Afterwards, over the course of 15 months, the researchers observed
honeybees and took note of which of the two patches the honeybees chose to
pollinate in.
The second phase of this study
involved a similar method to the first phase. The researchers created two
new patches of inflorescences. The researchers collected ant trail pheromones
from six different weaver ant colonies, and added 20 microliters of ant pheromone
to one of the patches, making it the experimental patch. The other patch was
used as a control in which 20 microliters of hexane was added. Hexane was used
as a control since it evaporated quickly and was commonly used for olfactory
bioassays. Prior research has shown that hexane does not influence or affect
honeybees, allowing the honeybees to choose between the experimental patch and
the control patch using their olfactory senses.
The researchers found that 60% of
the honeybees landed and pollinated on the ant-free control tree patch in the
first phase. Similarly, in the second phase, 63% of the bees landed on the control
inflorescent patch over the inflorescent patch treated with ant pheromone.
These results are significant as it supports the researchers’ hypothesis. The
results indicate that honeybees actually do eavesdrop and use their sense of
smell to identify and elude ant pheromones. This is important, as the bees may have
developed this ability as a result of evolution and natural selection to evade predators more
effectively. It is also possible that over time, the weaver ants may evolve in
which their pheromones become significantly more difficult to detect by the
honeybees.
Citation: Li, J., Wang, Z., Qu,
Y., Tan, K., and Nieh J.C. 2014. Giant Asian honey bees use factory eavesdropping to
detect and avoid ant predators. Animal Behaviour. 97:69-76
Its very interesting to learn that bees "eavesdrop" on ant pheromones and use it to avert the ants. Like you mentioned, it is also very probable that ants will likely produce pheromones that are undetectable in order to combat the unique "eavesdropping" ability of the bees.
ReplyDeleteIts interesting to see how different animals secrete signals for different reasons like how these ants use the chemicals to communicate with one another. Its also cool to see how the bees are using the signals to their advantage and to "eavesdrop" on the ants.
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