Biodiversity of Insect Vectors and Parasites: Prospects and Challenges in the 21st Century

Abstract

This paper examines diversity of insect vectors and parasites/vector-borne diseases also the successes and challenges in vector control in the 21st century and the way forward suggested. The generally accepted insect biodiversity is estimated to be 5.5 million worldwide with only about 1.5 million described. Generally, four insect orders: Coloeptera, Lepidopera, Hymenoptera and Odonata have been well studied and broadly described. Majority of insect species are known to be beneficial to man and the environment however, insect vectors which are fewer have been identified as causes of morbidity. Mosquitoes which are hematophagous insect vectors are known to be the leading vector for human infectious agents. Insecticides majorly dichloro-diphenyl-trichloroethane (DDT) were therefore used for the control of insect vectors. This succeeded only for a short while in the 19th century due to insect vector resistance and the widely condemned ecological disadvantages. This led to the development of safer and more effective insecticides such as the pyrethriods although also plagued with the tendencies of insect vector resistance. However, it has been strongly indicated that there are links between drivers of global biodiversity modification and vector-borne diseases. This is identified as the strongest reason for control programs that are all encompassing, engaging different fields and institutions, communities and individuals. The Integrated Vector Management (IVM) is therefore, advocated as the way forward for control of insect vector in the 21st century. It is encouraged to be practised putting the basic principles of biodiversity conservation which are ensuring biological diversity, ecological integrity and resilience in proper perspective.