Artemia cysts as an alternative food for the predatory bug Macrolophus pygmaeus B. Vandekerkhove 1 , L. Parmentier 1 , G. Van Stappen 2 , S. Grenier 3 , G. Febvay 3 , M. Rey 3 & P. De Clercq 1 1 Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium 2 Laboratory of Aquaculture & Artemia Reference Center, Department of Animal Production, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium 3 UMR203 INRA/INSA-Lyon, Biologie Fonctionelle Insectes et Interactions, Villeurbanne, France Introduction Macrolophus pygmaeus Rambur is a polyphagous pred- ator that is successfully used as a biological control agent against several crop pests in European green- houses (Perdikis and Lykouressis 2000; Martinez-Ca- scales et al. 2006). One of its main drawbacks is its relatively high rearing cost, mainly due to the inten- sive use of eggs of the Mediterranean flour moth Ephestia kuehniella Zeller as a food source. The mar- ket price of these eggs is currently around 500– 600 EUR/kg. Alternative, cheaper food sources may reduce the production costs and thus stimulate the use of this mirid in biological control (De Clercq 2004). The brine shrimp Artemia spp. can be such an alternative. These branchiopod crustaceans are routinely used as food sources in aquaculture (Lavens and Sorgeloos 1996) and their cysts are an Keywords biological control, brine shrimp, carcass analysis, factitious food, mass rearing, predator Correspondence B. Vandekerkhove (corresponding author), Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium. E-mail: bjorn.vandekerkhove@ugent.be Received: April 18, 2008; accepted: August 4, 2008. doi: 10.1111/j.1439-0418.2008.01332.x Abstract The suitability of cysts of the brine shrimp Artemia sp. as a factitious food for the predator Macrolophus pygmaeus Rambur was investigated. The influence of decapsulation time and hydration of the cysts on the per- formance of the predator were studied in the absence of plant material. A longer time of decapsulation had a positive influence on the develop- ment of the predator. Hydration of cysts had a significant impact on nymphal survival when cysts where non-decapsulated or poorly decap- sulated. An experiment in which nymphs were switched from a diet of hydrated cysts to non-hydrated cysts showed that in the absence of plant material the relative importance of hydrating the cysts decreased with nymphal age. Especially, the first instar and to a lesser extent the second instar appear to be susceptible to water shortage. Effects of pro- longed rearing on development and reproduction on brine shrimp cysts from different origins were tested in the presence of plant material. Rearing M. pygmaeus on Artemia sp. (Jingyu Lake) cysts yielded similar survival, development, adult weight and fecundity in the fourth as in the second generation. In contrast, for Artemia franciscana cysts, an increase in nymphal development was notable. Biochemical analyses showed that total amino acid content and the concentration of the dif- ferent amino acids did not differ among diets and generations. There were, however, differences in total fatty acid content between the differ- ent diets and generations and in the concentration of certain fatty acids, indicating that insects fed brine shrimp cysts may show nutritional defi- ciencies compared to those reared on a diet of Ephestia kuehniella eggs. Our results indicate that decapsulated brine shrimp cysts are an eco- nomically viable alternative food source in at least part of the rearing process for M. pygmaeus. J. Appl. Entomol. ª 2008 The Authors Journal compilation ª 2008 Blackwell Verlag, Berlin 1