The Menace of Locusts

The desert locust - schistocerca gregaria - is one of the greatest natural threats to agriculture, and hence to human life, in much of Africa and Asia. It can invade nearly 11 million miles, an area that contains roughly 20% of the world's land surface, 10% of the world's population and all or parts of 65 different countries.

Locusts normally live for about four months but they can slow down their body processes and extend their life span to a year if there is a shortage of vegetation or if the climate is cold. Each female locust produces about 200 eggs in her short life. The young locusts have no wings and are known as "hoppers". They live mainly in sandy desert areas. In dry years when vegetation is sparse locusts resemble green grasshoppers. They prefer to hunt about by themselves for food and to stay away from each other. Their desire for solitude disperses them over wide areas, thus helping the species to survive. But when, at rare and irregular intervals, there are heavy rains in the desert, they begin to breed in enormous numbers. Moreover, their manner and appearance change. They crowd together, touching one another's bodies repeatedly and their colour changes from green to black, yellow and red. They become voraciously hungry and set off in enormous swarms in search of food.

The ability of the locusts to change in appearance was first detected in 1921 by Sir Boris Uvaroy, now in charge of the Anti-locust Research Centre in London, and the leading world expert in the behaviour of these insects. His discovery answered one of the oldest questions about locusts: how did they vanish in some years and reappear in others? The answer was that they didn't vanish. They simply had a diabolical way of escaping attention. They change back to the form resembling ordinary grasshoppers and were mistaken for a separate species.

Locusts also have a remarkably keen sense of smell. This guide the migrating swarms to trees, crops and pastures in their search for food. They can fly at about 10 miles per hour but prefer to be carried by winds and can travel 30000 miles within their lifetimes. Since they breed as they go, the distance that a swarm and its progeny can cover becomes enormous. During the great locust plague of 1968 one group arose from the deserts in the far south of the Arabian Peninsula near Aden, pressed north-wards through Yemen and Saudi Arabia and then crossed the Red Sea turning south again to attack the United Arab Republic and the Sudan, thus travelling approximately 2,000 miles in eight months.

Research into locust behaviour is carried out in the London centre which actually breeds 600,000 locusts a year for experimental purposes. But efforts to control and contain the locust swarms are led by the Food and Agricultural Organisation (FAG) with headquarters in Rome and II field stations, all equipped with radio transmitters ranging from Morocco and Mauritania in the West to Persia and Pakistan in the East.

Unfortunately Nature herself cannot offer any serious challenge to the locusts once favourable conditions for breading have occurred and the swarms begin to multiply. The locust's natural enemies such as certain beetles, flies and wasps are neither sufficiently numerous or mobile to reduce the swarms to any extent and although birds regularly attack locusts their effect is only marginal. Man is now attempting to prevent such plagues by a variety of means.

One method is to scatter poisoned bait in the breeding grounds before the locusts begin to fly. Suitable bail is bulky to transport but can be spread by hand without expensive and sophisticated equipment. The chief difficulty is that the areas where breeding occurs are m- mainly uninhabited and themselves cover a very wide area. Another method is by insecticide sprays which are released on the swarms in the air by a fleet of light aircraft. Light oil is mixed with the insecticide to prevent if from evaporating in the sun or being washed away by the rain. One hazard which the pilots face is that the engines of their planes can become clogged with flying locusts which causes them to return to land. Attack from the air has of course proved vastly more effective than spraying from the ground but the real solution is to destroy the locusts before they become air-borne at all and this requires teams of locusts scouts whose job it is to report any signs of swarms forming.

Recently even space research has contributed to the anti-locust campaign. There is a U.S. weather satellite tracking station at Asmara in Ethiopia. The satellite in space transmits the pattern of wind zones to the station on earth and, since locusts tend to ride with prevailing winds, they normally congregate in a zone and scouts can know where to look for swarms.

Nevertheless human intervention has so far only managed to contain a plague, never yet to stop it from occurring. Yet even this resulted in the saving of 15 billion dollars' worth of crops in 1968, the most recent plague year.

The Arabs in the area of the Red Sea tend to take a philosophical view of the problem. "The locusts are there to show us that life is not ours alone", they say. "It is written that when there are no more locusts there will be no more world.”

The Hierarchy of Political Units

The earth's land surface is organised politically into a hierarchy of political units - both domestic and non-domestic - ranging in size and level of authority from the hamlet and the tribe to the largest nation. The hierarchy is seldom rigidly defined; i.e. seldom does one level of unit have absolute authority over another. (Witness the perennial controversy over federal versus states' rights in the United States and federal - provincial rights in Canada!) Nor is the hierarchy consistent throughout the world's many areas.

Except for nomadic tribes (and not all tribes are nomadic by any means), all these political units are sedentary and occupy specific areas of the earth's surface. Considered as a whole the units are numerous, and a world map of all would be complex indeed. Each unit has jurisdiction over certain functions of significance in economic geography; but since the scale of this book is global, we shall focus mainly on only the highest level of the political units and the most coarse of the political patterns - that of nations and their non-domestic affiliates.

Number and distribution: Over one hundred sovereign nations and a host of subordinate states, cities, and territorial dependencies provide political administration for the world's billions, Independent nations range from the tiny Vatican city-state with slightly more than 1,000 inhabitants, to Communist China with a reported population of over 700 million. Most nations contain more than 1 million and fewer than 60 million inhabitants.

Political units are composed of people - of the same 3½  billion people already stated to be very unevenly distributed over the earth's surface, The pattern of political unit is also uneven, and its irregularities do not coincide with those of population distribution when political units are combined there appears all too often a compartmentalization in which some nations, such as Libya are essentially devoid of population, where others, such as Belgium and The Netherlands, are almost unidentifiable portions of large population clusters, and still others, such as Canada and Australia, are lopsided imbalances of heavy population on one side and wide-open spaces on the other.

Effects on consumption and production: Government policy is intricately interwoven with economic activity. The kind and degree of government jurisdiction and/or influence varies from almost total control in certain Communist countries to an ambiguous but very important assertion in economies championing private enterprise, It affects consumption as well as production, especially by regulation of taxes and by other monetary means, but also by direct decree that becomes most conspicuous in time of war. All levels of government are involved, although in different ways. We shall elaborate upon the role of government in consumption and production at appropriate places in later chapters, but its importance in an assessment of economic geography should be appreciated.

Effect on exchange: A nation tends to be self-oriented. Except when there is aggression from the outside, a nation's existence depends upon the wishes of its citizens and/or its administrators, all of whom tend to place their own country's welfare above that of other countries. Hence a national boundary line, which appears unimpressive on a map and which is often unfenced on the earth's surface, can be a serious barrier to otherwise unhindered movement of commodities, currency, and people and, under extreme conditions, to communication. The major obstacles encountered at a political border include import, transit, and export tariffs, quotas, disease inspection (of both commodities and people); currency control - and immigration laws. These usually, but not always, restrict or limit incoming commodities and people and out-going currency. Whatever the restriction, it is usually intended to benefit the nation that brought it into being.

However, the division of the world's people into political units may or may not hinder their efforts toward economic cooperation, since a political boundary line is no stronger an obstacle than may be decreed by participating governments. If, therefore, a nation follows a policy of complete co-operation with all other political units, the "barrier effect" of its boundary lines is minimised. If on the other hand, the policy is of selective co-operation or of some form of isolation, the boundary obstacles may become almost insurmountable. In practice, the economic policies of political units range from almost complete isolationism to almost unrestricted co-operation, and the complexity of the world's economic geography is thereby increased.

Still more intricacy is added by the existence of non-independent political units that occupy a subordinate political and economic status. In international affairs, colonies and other absolute dependencies obey the decree of their respective mother countries, and quasi-independent political units follow their mother countries' guidance.

"Effective and outlying area ": Populations are unevenly distributed, not only for the world as a whole, but also for individual countries. Most political units are composed of one or more effective areas and one or more outlying areas. The former are invariably highly populated and are usually highly urbanized. Together with their immediate fringe territories, they enclose the portion of apolitical unit where things are happening - where the basic decisions are being made for the entire unit. The outlying areas, out-numbered in population and usually out-distanced in technical, social, and artistic development, are weaker in voice regardless of the type of government in power. Their chief contribution to decision making tends to be that of a brake - they are usually opposed to change, notably drastic change.

It is generally erroneous, therefore, to think of the pattern of political units in the traditional sense, as shown on the back end map of this book. Instead, if one wishes to be realistic, he should visualize the pattern of effective areas of the world on the front end map. This pattern, interestingly, is even less uniform in distribution than that of the political units themselves.

A very few nations, very small, very intensively populated, like Belgium and the Netherlands, do not exhibit effective area - outlying area relationships when viewed on a global scale - but even these break down into such components when the scale is enlarged.

The significance of effective areas to economic geography is enormous. Regardless of the scale of political units whether nations and overseas dependencies, component states, provinces, districts, countries, township, cities, villages, or hamlets - an effective area is usually discernible. Effective areas, therefore, are the mainsprings of consumption, production, and exchange for each political unit in question.