17. Function of Beneficial insects
helps to keep the population size and density
of other insects within reasonable limits
Predators are generally active in seeking out
their prey and they usually consume many
individual during their lifetime
A parasitic insects on the other hand,
generally attached to the body of a single
host.
A more extreme form of parasitism, common
in many insects, is where the parasitizing
insects is attached to or within the body of a
host and grows along with the host to a
certain point, eventually killing the host
Predation
and
Parasitic
Insects
18. Function of Beneficial insects
Decomposers
and
Nutrient
Cycling
Dead logs and branches are attacked by
termites, boring beetle larvae, and as
assortment of other insects, millipede, and
assorted invertebrate relatives. The nutrient
recycling by insects often takes a more direct
role
insects play an important role in the
degradation and ultimate consumption of
plant material falling into headwater streams
Scarabaidae consume great amounts of
dung, up to 10 or 12 times their own weight
per day, and also roll their eggs in balls of
dung, so that the emerging larvae can feed
on it. Usually the egg-bearing ball is rolled to
a suitable location and buried by the scarab
Insects also ‘create forest gaps’
19. Function of Beneficial insects
Insect
Pollination
Sexual reproduction in the higher plants is
made possible by the process of pollination
pollen being transferred from the stamens to
the sigma; from the sigma a pollen tube
grows down the style to the female germ cell
Without the pollinating services of bees and
other insects, we would have few vegetables,
few fruits, little or no clover, no coffee, no
tobacco, few flowers
20. Function of Beneficial insects
Weed
Management
feed on weed plants that are undesirable
from our point of view
beneficial by destroying noxious weeds, cacti,
or certain undesirable deciduous plants
weed control has been the use of insects in
controlling water plants that clog streams,
ponds, and lakes thereby ruining boating,
fishing and swimming
21. Function of Beneficial insects
Commercial
Products
Honey and Beewax
Honey is used extensively as a food and in the
manufacture of many products
Beewax is used extensively by industry in making
candles, sealing wax, polishes, certain types of ink,
models or various kinds, dental impressions, cosmetic
and other products
Silk- Silk, spun by larvae of the silkworm moth , was the
“ultrasheer” fabric, used primarily for hose and a wide
array of garment materials
Shellac - Shellac is produced from the secretions of the
lac insect, a type of scale insect occurring on fig and
banyan
Dyes – Insects have been the source of dyes and drugs,
but synthetic products have essentially replaced them.
The cochineal insect, Dactylopius coccus Costa , a scale
insect somewhat similar to the mealybugs, is used for
the production of cochineal dyes
