Artificial substrate for egg laying and embryonic development by the predatory bug Macrolophus caliginosus (Heteroptera: Miridae)

Macrolophus caliginosus Wagner is released in greenhouses mainly for controlling whiteflies, aphids, and thrips. Mass rearing of M. caliginosus occurs on tobacco plants and induces a high cost. The use of artificial substrates that allow egg laying and embryonic development of the bug is proposed. The number of eggs laid by M. caliginosus and the percentage of survival from egg to adult were compared on artificial substrates and natural host plants. A dental cotton roll wrapped in stretched Parafilm and wetted with water gave promising results as an artificial oviposition substrate. Its hardness was similar to that of the softest part of tobacco plant, and it received a mean of 1.2 eggs laid per day per female, with a 36.4% yield of larvae and 15% yield of adults (related to laid eggs). Meanwhile, under the same conditions, oviposition averaged 3 eggs/day/female on host plants. Spraying a substrate with ethanol leaf extract of Inula viscosa increased egg laying by M. caliginosus to a mean of 1.6 eggs/day/female. Egg laying and subsequent development to the adult stage were possible on an artificial substrate. However, greater efficiency must be obtained for economical mass rearing of M. caliginosus. (C) 1996 Academic Press, Inc.