Mycetoma

Mycetoma, a special formation in the bodies of various insects, usually paired and symmetrically located near the intestine and sexual organs. Mycetoma consists mainly of hypertrophied parenchymal cells, in whose protoplasm symbiotically living microorganisms are contained. Infection with them is constant for certain groups (for example, Homoptera) and is passed from generation to generation through eggs. The very growth of the mycetoma cells is considered a kind of inflammatory process—a reaction to the introduction of microorganisms. As for these microorganisms themselves, in different cases they belong to different groups. The most common here are blastomycetes (see), in Lepidoptera hyphal fungi close to Isaria are indicated, in Culicidae entomophthorales, and in cockroaches, rod-shaped bacteria are indicated as such symbionts. The general significance of mycetoma for the life of the insect is not entirely clear. Some attribute to them a role analogous to the spleen or lymph nodes in terms of protection against other infections, while others believe that mycetomas have significance in digestion (in aphids).