The adults are somewhat mosquito
like in appearance, they do not have piercing and
sucking mouthparts and therefore non-biting. (Photo)
Adult chironomids are short-lived,
reported to be about a few days.
Their flight ability is generally
weak and they disperse mainly by passive means like
wind, vehicles, etc
Most of the chironomid larvae are
aquatic and red in colour. Hence, the larvae are called
“blood worms”. (Photo)
However, a few species are green or yellow.
Polluted water apparently favours
their multiplication and emergence but relatively
clean water can also support their breeding. Most
of them are detritus feeders.
Members of this family are quite
common in Hong Kong.
Prevention and Control
Adult midges resting in vegetation,
shaded sand traps, indoor environment, etc. can be
knocked down by insecticidal aerosol.
Larvae cannot be suffocated by means
of malarial oil.
Insecticides and larvicides such
as B.t.i. can provide better control against the larvae.
Source reduction and water management
are regarded as the fundamental control measures.
Drains should be checked regularly to prevent accumulation
of water.
Larvicidal fish is a possible biological
agent when the water bodies cannot be removed.
The nuisance caused by the adult
midges can be abated, to a certain extent, by avoiding
the use of unnecessary lights at dusk.
Installation of protective nets
and screens of small mesh can ward off intrusion of
adult midges into indoor environment.
Last revision date: 03-07-2006