The Biotic Environment

the difficulty of dispersal of the pathogen referred to above and because other members of 713

the population may have varying degrees of resistance.

Density, distribution, and mobility of hosts are important factors in the development of an epizootic. Generally, epizootics are more likely to occur at high densities, even distribution, and high mobility of hosts, as the chances of dispersal of the pathogen are greater under these conditions. On occasion, an epizootic may develop at low host density, as a result of widely dispersed but long-lived pathogens that remain from a previous high-density outbreak. Even at high host-population density, an epizootic may not develop if the host population has a discontinuous distribution and/or poor mobility.

The importance of the environment, physical and biotic, in the dispersal and survival of pathogens has already been noted. Environmental factors are important in other ways in relation to epizootics. For example, factors that induce stress in an insect, especially extremes of temperature, high humidity, and inadequate food, may lower its resistance to a pathogen.

In conclusion, it is clear that whether or not an epizootic occurs depends on a variety of conditions relating to pathogen, host, and environment. Only when knowledge of all of these factors is available for a given host-pathogen interaction can an accurate forecast of a potential disease outbreak be made. Such knowledge is of critical importance in determining the success or otherwise of biological control using pathogenic microorganisms.

Beekeeping for Beginners

Beekeeping for Beginners

The information in this book is useful to anyone wanting to start beekeeping as a hobby or a business. It was written for beginners. Those who have never looked into beekeeping, may not understand the meaning of the terminology used by people in the industry. We have tried to overcome the problem by giving explanations. We want you to be able to use this book as a guide in to beekeeping.

Get My Free Ebook

Post a comment