In most cases, the parasitoid or predator is searched with an innate potential for increase greater than that of the host/prey. One important factor in the display of density responsiveness is high reproductive capacity through either short generation time, high fecundity or both. A rapid and strong numerical response characteristic is the most important attributes of a successful agent of pest mortality. A strong functional response refers to within generation behavioral activity of the individual parasitoid or predator in increasing its attacks against increasingly numerous hosts or prey, on the other hand, numerical response refers largely to a multigenerational reproductive increase by the organism in response to increasing host density. Generally natural enemies have short life cycle, whereas pest has long life cycles. Proportion of natural enemy of pest should be maintained. The most desirable biological control agents should exhibit positive rapid density responsiveness.

The practice of periodic inundative release of beneficial insects is another way of artificially synchronizing the occurrence of parasitoid and host e.g. The efficacy of poorly synchronized organism may sometimes be improved. Thus the reproductive stage of a successful egg parasitoid must be active at the time of the hosts egg in every generation of the host. The pest and its natural enemies should be in the same place at the same time and also their life cycles must be synchronized for adequate regulation to be possible. high humidity by irrigation for development of pathogenic fungi against alfalfa aphids. Disparity in ecological responses may be an important limiting factor in the effectiveness of native beneficial organisms and an environment manipulation of same sort may make them successful regulative agents e.g. and hence it is of great consideration for parasite species to withstand such condition suitable for the host.

Parasitoids are frequently limited in effectiveness and have greater sensitivity to cold desiccation, heat etc.

It is usually important to seek species whose ecological requirements are similar to those of the intended target insect. The Organisms should Possess Following Attributes: Thus proper selection of natural enemies of insect is an important part of success of Biocontrol. Before introducing new natural enemies from exotic locations or analyzing those species which are already present for same way of augmenting their usefulness we must know their characteristics of species to display it an efficient regulatory relationship with the pest. In order to search for efficient beneficial organisms for use in biological insect pest suppression it requires some idea beforehand that what we are seeking. While introducing beneficial organisms, the concern of the desirable attributes of a natural enemies and a consideration of some basic ecological principal have bearing as success or failure of biological pest-suppression programmes. The classical practice of introduction exotic beneficial organisms or pest suppression is the only useful method under restricted conditions.

Characteristics biocontrol agents