Birds, as is well known, function as an important natural check on the increase of insect population. In the early years of agriculture birds were considered the first line of defense against insect damage.

It is interesting that most of the early studies in the economic ornithology were not done by ornithologists [people studying birds] but rather by entomologists [those studying insects].

The recognition of the value of birds in combating insect pests has led to efforts not only to protect insectivorous species but also to increase their numbers by providing nest boxes and improving habitat, but at a very limited scale hitherto by the vertebrate pest control institute, Karachi University campus.

Nest boxes have successfully been used for hundreds of years on a large scale in Europe to attract birds that control forest insect pests .In USA a study of insectivorous birds feeding on the insect pests of white oak [quercusalba] concluded that predation reduced insect number by 50 per cent and resulted in one third greater growth of the oaks.

Control of locusts that had been a chronic problem on 8200 acres of grassland in China was achieved by using birds. This was done by creating nesting habit, planting small shrubs, and digging water seeps to increase the number of insectivorous birds. Control was successful for many years. Predation of grasshoppers by birds was found in food habit studies of rangeland birds foraging at edges of Montana wheat land, USA.

According to a study undertaken at the locust wing of the department of plant protection, Government of Pakistan, Karachi, destruction of locusts by birds continues not only when the locusts are at the peak of their periodical abundance, but also when their population is at low ebb. Hussain and Bhatia [1931] of ministry of food and agriculture, government of India, has listed 35 species of birds, belonging to 18 families, attacking locusts.

Important species includes common crow [corvus splenders], the rosy pastor [pastor roseus] locally known as wahyo or tilliar, common myna [acridotherus tristis], and the grey partige.

According to these research workers, birds render valuable service in terminating thin locust swarm and destroying the escapes. Crows, kites and cranes cherish on locust swarm. Review of literature has indicated that young ones of starlings, in the first few days of their lives consume more than their own weight of food and a pair of starling conveyed food in the form of grasshoppers and locusts to their nest 370 times during a day.

According to an interesting Hindu legend, locust had been imprisoned in response to the prayers of the people, in deep valley surrounded by impenetrable mountains in the west of Himalayas. The exits from the valley are guarded by tilliar [wahyo] commissioned by heaven for the purpose.

Now and then when the sentinels fail in their duty of watch and ward, the locust escape and hotly pursued by the tilliar, who unable to drive them back to their place in the hills, slay them wholesale.

As a matter of fact during antilocust campaign, as per locust wing of the plant protection department, a concentration of a large number of flying birds especially tilliar is generally indicative of either the existence of a water reservoir or locust infestation-swarms or hoppers.

Thus anti-locust squads have very often been able to locate locust infestation from a distance, being guided by the sign of a concentration of hovering birds. Birds are said to have a very poor sense of smell but possess highly developed power of sight, as they surpass all other creatures in their ability to adjust the focus from a distance to a nearby object almost instantly.

An American naturalist has remarked that in the fraction of a second the eye of a bird can change itself from a telescope to a microscope. This is how birds are easily able to locate the whereabouts of locust, which during the swarming phase have generally conspicuous colours.

Besides locust and grasshoppers [Family-Acrididae], one another insect pest of the same order is field cricket [Family-Gryllidae]. These are usually somewhat short dark coloured orthoptera with the tarsi three segmented like the grasshoppers, but the antennae are very long.

Moreover, contrary to grasshoppers crickets are nocturnal and negative to light. They feed upon variety of substances .The ordinary black field cricket is also known as cricket of the earth. In riverine belt of river Indus which is known as kutcho area the soil is alluvial. The top layer being soft clay up to a depth of 3-4 inches with hard clay below. When the land is dry after irrigation or rain or flood cracks as deep as 9 inches appear throughout.

This very condition of soil provides ideal ground for the mass breeding of field cricket. Following no rain or very little rain for the last 3-4 years till 2002 monsoon rain as well as prolonged absence of flood in the kutcho area allowed field crickets to thrive its population in this special type of soil in the riverine belt of upper Sindh particularly in district Khairpur, Sukkur and Ghotki.

After harvesting of wheat crop when cotton is grown in the very special type of soil in kutcho area the very cotton crop come under cricket attack. The cricket manages to eat the cottonseed while it is imbedded in the soil after sowing. In case of severe cricket population in the field, cotton also sustains damage while in the seedling stage. Since growers are not aware of the mode of damage of cricket as well as behaviour of the menace including its control measures, it was observed by this scribe that poor plant population in the field in general is attributed to substandard seed quality by the ignorant growers.

Whereas the factor behind poor plant population is cricket which damage seeds prior to its germination. During kharif 2003 season last year, this very writer had the opportunity to survey the cotton area in kacho area of Khairpur district.

During the survey it was observed that growers in general use flooding of the field to flush out the cricket. However the most exciting phenomenon, which was observed, was landing of large nubmer of birds especially bagula [heron] and common myna in the cotton field under irrigation.

Soon after landing these natural control agents were seen preying upon the crickets, which were coming out from the soil following irrigation water. According to the poor tenant of the landlord concerned, it is the birds that came to rescue them from the very hidden menace. But problem with this natural control, according to the haree [tenant] was that period of first irrigation falls 2 0 to 25 days after sowing by that time cricket manage to damage most of the seedlings.

Suggestions: Since cotton in kacho area has surpassed over one-lakh acres in the upper Sindh and field cricket is a chronic problem of this area, it is warranted that shooting of birds is banned in the kacho area. Besides, growers in general are not aware of field cricket control strategy friendly to the environment. It is therefore, imperative that control strategy appropriate for this area is made available to the growers of katcho area by the agriculture extension department government of Sindh.