Microbes in the diet setting
The symbionts may be essential to the well-being of the insects, most often in a nutritionally beneficial relationship where the microbe guest repays its host’s hospitality by synthesizing an otherwise unavailable or poorly available nutrient. Termites and their microbes are excellent examples of such mutualism, as are cockroaches and their symbionts and most homopterans and their microbes. In using artificial diets for insects that rely on such relationships, the danger is not in contamination, but rather in disruption of the relationship by inadvertent removal of the microbe or of its means of gaining entry in or access to the host. Even with the so-called commensals it is possible that there is a cryptic benefit (i.e., a hidden mutualism) that we may disrupt by our rearing efforts. These relationships are further discussed in Chapter 7 on feeding.