Chapter 7 - Culture and colonization

Abstract

The culture and colonization of natural enemies are fundamental to biological control work. The three principal reasons for culturing parasitoids, predators, and pathogens are to provide field-release organisms for permanent establishment, periodic colonization, and inundative releases. Foods employed in rearing the hosts of entomophagous organisms are in decreasing order of difficulty of provision—living plants; harvested plant parts; tubers, fruit, and other produce; and prepared diets. The actual laboratory production of insects is dependent on the environmental conditions. Combinations of light, temperature, and humidity, as well as the sequences of these combinations, are particularly critical in managing the development of insects that undergo facultative or obligatory diapause. Obligatory diapauses, in particular, cause severe production problems, but both facultative and obligatory diapauses are useful for long-term insect storage. There are many and varied techniques for arthropod rearing. Stockpiling refrigerated hosts is very helpful and the determination of the effects of refrigerated host material on parasitoid and predator production must be on a case-by-case basis. Differential cold storage of the sexes is useful for synchronizing emergence, because males of most of the insects develop more rapidly than females and emerge first.