Abstract:
Botanical Insecticides:
Botanical insecticides are insect killing chemical substances obtained from plants. These chemicals include an array of glycosides, alkaloids, saponins, tannins, essential oils, cyanogen’s, phenolics, amino acid analogs, non-protein amino acids, proteinase inhibitors, cardiac glycosides, and other organic compounds, whose metabolic functions are presently obscure (Young ken 1950).
Prospect of the botanicals:
Plants are considered to be the most potent to human beings not only because of their support for food and shelter, but also because they provide all the requirements for the survival of the civilization during the past few decades. The world advanced rapidly with remarkable development in pesticide technology and medicine, but there are still some problems especially for undesirable changes in gene pool for the presence of some mutagenic agents. So, a question has arisen for sustainability and the survivability of the living beings on the planet with no hazard environment. Hence, a worldwide interest has created in the revolution and use of age- old traditional botanical agents (Heyde et al. 19 84).
Several insecticides have been tried to control the insect pests. Control by chemical insecticides are very effective, but indiscriminate use of chemical pesticides has given rise to many serious problems, including resistance by pest species, environmental pollution, threat to wild life, motivation by weather, hazards from handling etc., as mentioned earlier These hazards have created awareness to people and developed a worldwide interest for the use of botanical pest control agents as botanicals are comparatively safer to mammalian and higher animals ( Feinstein, 195 2).
In the rural areas of Bangladesh, farmers traditionally mixed leaves, bark, seeds, roots or oils of certain plants with stored grains to keep them free from insect attacks. Such techniques have been inherited as part of traditional culture (Saxena et al. 198 9). Recently a number of investigators isolated, identified and screened chemical compounds from plants and reported the effective use of these materials as insecticides against stored grain pests (Ahmed et al. 1980, Khanom et al. 1990a, b; Khalequzzaman and Islam 199 2a, b; Talukder and Howse 1994).
Description:
This thesis is Submitted to the Institute of Biological Sciences (IBSc), University of Rajshahi, Rajshahi, Bangladesh for The Degree of Doctor of Philosophy (PhD)
