Locust Control Management: Moving from Traditional to New Technologies – An Empirical Analysis

"> Introduction
Devastating locust invasions have been recognized as a major
threat to agriculture and mankind since ancient times. The infestations
of locusts which ravages vast areas of land under a variety of vegetation
which affects wild plants, pastures, forests and cultivated plants at
different stages vary greatly from year to year and from country to
country resulting in heavy crop losses and also setting in motion a chain
reaction with far reaching effects such as famine, disruption of trade,
abandonment of cultivation, diversion of labour, heavy expenditure on
control measures and so on.
Globally, about 64 countries representing 20% of land surface
(approximately 30 million square kilometers) is subject to ravages of
the desert locust during plague period. During recession when desert
locust population occurs at low densities infestation is confined to 16
million square kilometers arid areas in 30 countries of North Africa,
Middle East and Northwest India. These countries were subjected
to periodical invasions of locust swarms which attacked almost all
varieties of natural and cultivated vegetation often resulting in famines
and immense economic losses. Locust invasions are dramatic, sudden,
cover large areas in a short period and almost all green in their path
is destroyed. It is the destructive potential which is dreaded as locusts
come so suddenly in such large numbers and swarm across international
boundaries and due to this reason locust invasion attract so much public
attention and cause international concern. Locusts are invertebrate
animals with highly migratory habits, marked polymorphism and
voracious feeding behavior. They are able to take rapid advantage of the
climate and geography can survive in temperature range from 0 degree
to 60 degree and can speed up or slow down their life cycle.
Difference between locusts and grasshoppers
Both locusts and grasshoppers belong to the same family of insects
known as Acrididae (legs unequal in size, antennae shorter than body,
tarsi–3 jointed, auditory organs on the first abdominal segment,
ovipositor short). Locusts differ from grasshoppers because they have
the ability to change their behavior and physiology, in particular their
color and shape (morphology) in response to changes in density. Adult
locusts are capable of forming large migratory swarms which behave
as a unit and may contain thousands of millions of individuals or
the non-flying nymph or hopper stage which form bands. A band is
a cohesive mass of hoppers that persists and moves as a unit. When
the locusts exist as gregarious individuals then they migrate during day
time in swarms containing many millions of individuals. When the
locusts exist as solitary individuals then distinction between locust and
grasshoppers breaks down completely. Thus locust is the name given
to the swarming phase of short horned grasshoppers, some species of
which under favorable climatic conditions congregate, move together
as bands and swarm over long distances crossing over countries
and continents rapidly stripping fields and enormously damaging
crops. Some species swarm over short distances and are confined
within a country to certain defined ecological zones. In general, most
grasshoppers do not form bands or true swarms. The distinction
between locusts and grasshoppers is not clear - cut since some of the
latter do form bands (e.g. Melanoplus, Acridoderes, Hieroglyphus sp.)
or small loose swarms (e.g. Oedaleus senegalensis). Locusts such as the
Tree locust have never been known to form bands.