Midges
Chironomus species
Phylum:
Arthropoda
Class: Insecta
Order: Diptera (two-winged)
Adult Midge
Although these flies resemble mosquitos, they are very different. Chironomus is a non-biting midge.
They are in the Order known as "Diptera", because of the Greek naming system, in which "Di" means two, and "ptera" means wings. The flies in this Order, are known as "true flies".
The young
of these midges do not look like flies at all. They look like worms. They
are sometimes called 'bloodworms' because of their bright red colour,
although some are pale or green.
Habitat
The young
midge larvae ("bloodworms") live in freshwater ponds, lakes
and rivers. They can tolerate very low oxygen levels and are often found
in very large numbers in the sludge at the bottom of stagnant ponds.
The adults are often found flying in dense swarms near the water's edge.
Moving around
The "bloodworm"
larvae swim by wriggling in a figure of eight looping motion.
The adults fly!
Feeding
The larvae eat: dead plant and animal material (detritus) at the bottom of the water. They also eat bacteria in the mud, and are important in helping to dispose of human waste in sewage plants.
They are eaten by: fish, water mites and insect larvae.
Most adult midges do not feed, but are themselves eaten by birds.
Reproduction
Midge pupa
This is a process known as complete metamorphosis.
The larvae live in water, and then turn into a pupa in the mud. The pupa swims to the surface and emerges as an adult midge.
These midges then lay their eggs into the pond, in jelly strings (see below), which in turn, hatch into worm-like larvae.
Breathing
The "bloodworm"
larva contains a substance which is similar to haemoglobin (found in human
blood). This is very good at holding oxygen, which is absorbed through
gills at the base of the body. It is bright red.
Size
The "bloodworms" are 15 mm long.
