Pest Problems
The term "pest" is generally defined as a harmful or hazardous organism. In the biological fields, pests represent animals or plants which destroy, suppress or compete with desired animals or plants in a given environment. Plant pests are generally referred to as weeds. Animal pests which attack crops and pastures can be classified as migratory, e.g. (birds, armyworms, locusts) or semi-migratory/residents (e.g. rodents, vermins, molluscs insects/nymphs and microbial organisms). Rodents and other vermin are also reservoirs and carriers of diseases. Some arthropods and particularly some insect species are important animal parasites and disease vectors.
Hazards brought about by plant and animal pests in agriculture, livestock industry, public health, and the environment are of major economic importance and of worldwide concern. These hazards are particularly felt in the developing countries where pest management is relatively more costly to execute due to a generally poor underlying economy.
Pest management activities in Tanzania have rarely been supported by thoroughly controlled local studies, instead, most pest management interventions have been carried out in "crisis" and on the basis of data obtained elsewhere, usually from the "developed" countries. Such control activities have often also been planned, financed, and carried out by foreign consultants or under their supervision. Consequently, pest control measures have been erratic, poorly monitored, and have lacked sustainability.
Sustainable crop pest management research in Tanzania is essential because yields for most crops in Tanzania have, on average remained low due to pests. For example, in Tanzania, an annual average of 640kg/ha for beans is achieved compared to 3000kg/ha obtained in USA. The use of pesticides commonly practised in most developing countries offers only a temporary solution to the pest problem and moreover, most farmers cannot afford the cost of the pesticides. In addition, the use of pesticides without sufficient knowledge of their side-effects may create serious problems to the environment. For example, in recent years pesticide resistance by common pests, and pesticide residues in fruits, grain, and animal produce have increased in the developing world due to irrational use of pesticides. Pest biology, ecology and diversity, and the description and quantification of crop damage have been little studied in Tanzania. This knowledge is fundamental towards achieving a sustainable crop pest management in the future and SUA should take the lead to achieve these goals.