These photos are some of the laminated ones that were got prepared by me when I was Plant Protection Officer (E) at Locust Circle Office, Jalore, (Rajasthan) for displaying at the Farmer's Fair and in the office.

Desert Locust Photos

Gregarious Desert Locust

Copulating Solitary Desert Locust

Egg laying by female Desert Locust

Egg pod of Solitary and Gregarious Desert Locust

Different stages of Solitary Desert Locust Hoppers

Different stages of gregarious Desert Locust Hoppers

Difference in fifth stage hopper of solitary and gregarious Desert Locust

Immature solitary male and female Desert locust

Immature and mature male gregarious Desert Locust

Hoppers of gregarious Desert Locust

Egg laying by gregarious female Desert Locust

Gregarious hopper undergoing moulting

Gregarious Desert Locust swarm in warm morning sun

A flying swarm of gregarious Desert Locust

Difference between male and female Desert Locust

A farmer troubled by gregarious Desert Locust hoppers

Distribution map of desert locust in the world

Solitary desert locust

locust eating bajra

Locust eating bajra

Gregarious locust hoppers

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

For more details contact the author at
locustexpertanil@gmail.com
anilsha2@rediffmail.com
 

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

The desert locust (schistocerca gregaria forskal)
The life cycle of the desert locust consists of three stages: egg, hopper
and adult and duration of the life is 2-6 months on an average. The eggs 
 are laid by females in pods in the moist sandy soil at a depth of about
10 cms. Egg pods are laid at intervals of 7-10 days. Gregarious females
usually lay 2-3 egg pods, each with about 60-80 eggs. Solitarious females
mostly lay 3-4 times. Each pod contains 100-160 eggs. The rate of egg
development is dependent upon soil temperature and moisture. There
is no development below 15 degree centigrade. The period of incubation
decreases from about 70 days at 19 degrees centigrade to 10-12 days at
32-35 degrees centigrade. Rates of egg development have been found to
be characteristics of particular seasonal breeding areas and can be used
to forecast dates of hatching. After completing the incubation period
the eggs hatch and nymph (young ones) emerges. There are five instars
in gregarious population and 5-6 instars in solitarious individuals. In
each instar there is growth of nymph and the colour of the solitarious
hopper is green throughout all instars but the gregarious hoppers have
characteristic colouration of black and yellow. The rate of development
of nymph is mainly dependent on temperature, from about 22 days
under hot conditions (mean air temperature approx. 37 degrees
Celsius) to over 70 days under cool conditions (mean air temperature
approx. 22 degrees Celsius). Fifth instar hopper moults into the adult
state. This change is called fledging and young adult is called a fledgling.
After this there is no further moulting and the adult cannot grow in
size but gradually increase in weight. Fledglings gradually become hard
and able to fly. Locusts in this condition are called immature adults.
The period of sexual maturity of adults is very variable. If conditions
are suitable, the adults may mature in 3 weeks. More usually, however,
they migrate downwind until they encounter favourable breeding
conditions, which may be thousands of kilometers away. Under cool
and/or dry conditions they may remain immature for as long as 8
months. Young immature gregarious adults are pink but old ones may
become dark red or brown under cool condition. On maturation adults
become bright yellow. Males mature before females but oviposition
usually commences within two days of copulation.
   0px; "> The desert locust exhibit two distinct behavioral phases – the
solitary phase – when individual actively avoid one another and – the
gregarious phase – when they form marching hopper bands (mass
aggregations of flightless nymphs) and swarms (adult aggregations with
high mobility). Both these stages of gregarious phase, hopper bands
and swarms are capable of devastating crops and pastures [1-3]. A
series of complex interaction between high rainfall, high survival rates,
the lush green vegetation and the behavior wherein there is an increase
in the rate at which hairs on the back legs are touched by other locusts
in a group is responsible for change from the solitary to gregarious
phase [4]. The desert locust only migrate to invasion areas in the form
of swarms once they begun to gregarise [5]. Dense groups that have
strong cohesion among individuals migrate long distance together are
swarms and their size may range from less than one to 300 sq miles.
The biggest swarm recorded in India being 1200 sq miles. One sq mile
of locust swarm may weigh about 150-200 tonnes and consumes 200
tonnes food daily. The swarms have been known to travel over 250 km
in a day and as much as 4500 km in a month and may fly 2000 km at a
stretch and at height of 7000 ft. and fly generally at the speed of 12-15
km per hour and on an average 9-12 hours per day, generally move into
areas of low level convergence of winds (Inter Tropical Convergence
Zone) and move down wind, fly during day time and settle by nightfall.
En route mature ones settle on ground for breeding while those not yet
mature fly on. A copulating and laying swarm usually stays in the same
area for 3-4 days.
 Solitarious adult occur at low density or individually, starts flying
after dusk on warm evening and can migrate long distances during
 dth: 0px; "> night. During day time they fly or flush only when disturbed and fly
low, settle quickly, eats it own weight of food per day (about 2.5 gm)
and are generally bigger than its gregarious counterparts. The desert
locust has no fixed or static outbreak area where a swarming population
can be observed and controlled, as in the case of the Red Locust and the
African Migratory locust. On the contrary, the Desert locust is able to
breed, when suitable conditions prevail, in any part of its distribution
area. The desert locust is one of the most difficult insects to control on
a national basis due to the vastness of its distribution area, pronounced
adaptability to utilize wide range of environmental conditions,
migratory nature and the potential ability of swarms to fly thousands
of kilometers, and the speed at which they can move from one part to
another. Thus the presence of swarms in any country is a threat to other
countries, even though these countries may be thousands of kilometers
away from the source of invasion. This fact calls for the importance of
international cooperation in desert locust control.
As the desert locust belt is so vast and includes many countries and
places that vary in many ecological, geographical and climatological
aspects and in view to control this pest the International Conferences
have divided the Desert Locust belt into following five regions and each
region consist several countries having special desert locust cycles and
movements. The activities between all these five regions are coordinated
by the FAO. Its breeding seasons have also been demarcated. For
example there is a particular cycle for the eastern region where
movements of swarms occur in India, Pakistan, Iran and Afghanistan.
There is also a cycle of this pest in East Africa, in North and West Africa
and in the Arabian peninsula and the North East countries.
1. South West Asia Region—India, Pakistan, Iran and
Afghanistan.
2. Near East Region—Iraq, Jordan, Kuwait, Lebanon, Saudi
Arabia, Syria, turkey, Egypt, United Arab Republic, Bahrain,
Yemen Arab Republic and the People’s Republic of Southern
Yemen.
3. East African Region—Ethiopia, Djibouti, Somali Republic,
Sudan,Kenya, Tanzania and Uganda.
4. Northwestern African region—Algeria, Libya, Morocco and
Tunisia.
5. West African Region—Chad, Dahomey, Cameroun, Gambia,
Ivory Coast, Mali, Mauritania, Niger, Senegal and Upper Volta. 

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.

Identification of The Migratory locust

Migratory locust imagos can be accurately identified according to the following criteria :

General morphology

Size : Males are 42-55 mm long, females are 54-72 mm long.

Overall body colour

Two colours are noted in the solitary phase : green and brown.

In the solitary phase, imagos are generally green or brown with various degrees of black, yellow or brown spots. In natural populations, there are seasonal variations in the percentage of green and brown forms. Green forms predominate in the wet season, with brown forms being more common in the dry season.

In the gregarious phase, imagos are solid yellow with heavy black maculation. Gregarious hoppers are yellow with dark black markings. Solitarious hoppers are green or brown.

Wing colour

Completely transparent, never any colouring.

No prosternal tubercle