It is by end of August or in September that the life of an
asian hornet colony begins. It is at this moment that the
breeding of the sexual generation begins. The queen of the
year lays non fertilized eggs which will give males and,
at the same time, fertile eggs which will give females.
Is it the presence of the males in the brood that determines
the production of sexual females. It may be that the females
which will become queens receive different feeding from
that received by the workers. With a better feeding they
should be able to develop sexually whereas the workers remain
sterile. One day Science will be able to understand the
difference which produces a worker or a young future queen.
As the queen becomes adult, the sexual females escape
from the nest together with the males which will fertilize
them. Some go far away, some others stay near the area where
they are born. They will rest during the winter in any natural
such as trees, burrows, holes or any other space which will
protect them from cold.
In Spring, February of March, depending upon the weather of
the area, the young queen begins to dance in order to find a
place where to set up its colony. She begins to build a nest,
initially as big as a hen’s egg. The young queen will
collect various materials to build the nest. She will also
need great quantities of water to produce pulp to strengthen
the nest. Soon she will also need insects to feed the
larvae. She will breed alone the first brood of workers which
will be the size of a wasp and which will be born over five
weeks after which they will leave the nest.
It is at this
moment that we will wait for them with our traps to try to
capture them. Without them the nest will be condemned to die,
even before being active. But many others will avoid the traps
and survive. It is necessary to seek them out during the
summer, before the end of August, in order to exterminate them,
since at this time, the sexual reproduction will begin again.
As soon as the number of workers become sufficient (50 to
60) to undertake the enlargement of the nest, the young queen
will not help anymore. She will only lay. Until the end
of the summer, she will lay only fertilized eggs which
will give birth to workers. Then the laying of the sexual
generation will continue until October.
When a queen dies, sometimes, a worker takes her place and
begins to lay but, since she is not fertilized she will
produce only males off spring and the colony will die early in
the summer. From mid-September to end of October, the queen
will decline. Some of them will not have enough reserves of
sperm, therefore they will only lay unfertilised eggs. This
will mean the demise of the colony because the males do not
participate in the activity of the colony. These colonies will
be the first to die.
In September, they are still some colonies which have
few males and lot of workers and a small brood ; this explains
that they are still alive. In a nest caught last year, there
was still a small brood alive, some larvae and enough insects
to discourage the birds from eating the larvae. But the colony
gradually dies. Some adults remain active for some time but
the cold and old age result in the demise of last
The birds are free to eat the larvae.