Filth Fly Management in Urban Environments - Urban Insect Pests: Sustainable Management Strategies - page 48

Fig. 4.7. Eye gnat.

strongly attracted to moisture around the
eyes and nose of people or animals outdoors.
Eye gnats hover around the face, causing
considerable annoyance, and can potentially
infect people with bacteria or viruses that
cause pinkeye (conjunctivitis), a redness
and swelling of the mucous membrane that
lines the eyes.
Eye gnats breed outdoors in soil with
high organic matter, decaying vegetation
and animal excrement. The life cycle varies
from 7 to 28 days, depending on the tem-
perature and moisture. These fl ies are
attracted to light and enter homes through
open doors or windows.
Phorid fl ies (Fig. 4.8), also known as
humpback fl ies, due to their humpback
appearance, or cemetery fl ies, due to their
presence in cemeteries and other places
where corpses are buried or otherwise
disposed, are very common throughout the
world. These fl ies are about 2 mm long with
a small head and large thorax, which causes
the humpback appearance that gives rise to
the common name for this fl y. Humpback
fl ies breed in high-protein waste and other
decaying organic matter, and even in ant
and termite nests. Many other fl ies in the
Phoridae family can have very different
development requirements, with many of

the phorid fl ies developing as parasites in
other living organisms. Humpback fl ies do
not fl y in areas of high air movement but are
easily disturbed when approached.

Problems Caused by Flies in Urban
Environments

Flies can be serious pests in urban
environments due to disease transmission
and movement of fi lth (Graczyk et al ., 2001).
Flies also deposit regurgitated food and
excrement on surfaces, and annoy people
by fl ying, buzzing and landing on food and
other areas often making human life
uncomfortable.
Due to their development and living
requirements, many of the fl y species visit
unsanitary locations, and then visit areas
humans want to maintain clean. While
moving between fi lthy and clean areas, fl ies
spread pathogens and other microbes
(Förster et al ., 2007; Butler et al ., 2010),
which may cause health problems to both
humans and animals. It also leads to quality
degradation of food and other products
humans consume. The most serious prob-
lems caused by fl ies are the spread of patho-
gens, especially ones that cause digestive