Resistance to Disease

Resistance to disease may be considered to include two components, prevention of entry of the disease-causing organisms and rendering harmless organisms that do manage to reach the body cavity. The insect cuticle, covering the entire body surface, tracheal system, foregut and hindgut, and the peritrophic matrix lining the midgut are major obstacles to the entry of such organisms.* A considerable number of potentially dangerous microorganisms must be ingested during feeding, yet normally these have no detrimental effect on the insect. What little work has been done suggests that specific substances in the gut deal with these organisms. For example, bacteria (especially gram-positive forms) appear to be digested by lysozyme. Though this enzyme is normally produced in the midgut, in mosquitoes the salivary glands are its source, perhaps to provide early protection against bacteria that enter the alimentary canal in ingested nectar (Moreira-Ferro et al., 1998). Substances with antiviral activity are also known to occur in the gut, though their nature and mode of action have not been studied.

Hemolymph plays a major role in an insect's resistance to disease. It is important, through its role in wound healing, in preventing entry of pathogenic organisms, and in the destruction of organisms that manage to enter the body cavity.

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