Evaluation of a rearing-method for the predator Orius insidiosus

The development of mass-rearing techniques is aimed to produce large numbers of natural enemies of a good quality at a com-petitive price. The objective of this study was to investigate a rearing-system for Orius insidiosus (Say) (Rhynchota Anthocori-dae). Three types of containers and different densities of eggs of the predator per container were tested in a climate room at 26 ± 2 ºC, 70 ± 10 % RH and photophase of 12 h. Also, one type of container and different densities of adults of the predator were tested. The immature stages were reared in plastic bags, Petri dishes, and glass jars at densities of 100, 250, and 400 predator eggs. Glass jars were used to rear adults, at densities of 250, 400, and 550 adults. Both Petri dishes and glass jars were suitable for rearing O. insidiosus at a density of 100 eggs per container, with a mass-production of newly-emerged adults of 55.2 % and 50.5%, respectively. At the density of 250 eggs per container, only glass jars were suitable for nymph rearing with 53.6 % produc-tion of adults. For adult rearing, the density of 400 adults per container was most suitable, with the highest number of eggs laid per female. The results showed that glass jars were best compared to others containers tested for the O. insidiosus rearing. Corru-gated cardboard strips as hiding places for nymphs and adults, eggs of Ephestia kuehniella Zeller as food, an inflorescence of Bidens pilosa L. as oviposition site and a source of moisture should also be included to maximize the mass-rearing efficiency of O. insidiosus. This rearing-method could be a starting mass-rearing system for O. insidiosus in our conditions and that would be improved in co-operation with a Brazilian producer of natural enemies. Key words: biological control, mass-rearing methods, Orius spp., predator, food, oviposition site