1. Laboratory of Entomology, Wageningen University & Research, P.O. Box 16, 6700 AA Wageningen, the Netherlands.
2. Animal Nutrition Group, Wageningen University & Research, De Elst 1, 6708 WD Wageningen, the Netherlands.
3. Department of Environmental Sciences and Natural Resources, University of Alicante, P.O. Box 99, 03080 Alicante, Spain.
4. Department of Entomology, Texas A&M University, College Station, Texas 77843-2475, USA.