Six new cell lines were established from embryonic tissues of the diamondback moth,Plutella xylostella (L.).The cell lines showed differential characteristics,including growth in attachment or in suspension,susceptibility to a baculovirus infection and expression of genes involved in the glucosinolate detoxification pathway in P.xylostella larvae.Five of the cell lines grew attached to the culture flask and one cell line grew unattached as a suspension cell line.The cell lines had population doubling times ranging from 18 to 23 h.Among five of the P.xylostella cell lines examined for infection ofa nucleopolyhedrovirus from Autographa califoica,AcMNPV,four cell lines were highly susceptible to AcMNPV infection,but one was only semi-permissive to AcMNPV infection.The production of two recombinant proteins,a β-galactosidase of bacterial origin and a secreted alkaline phosphatase of eukaryotic origin,in the P.xylostella cell lines was examined in comparison with that in the cell line Sf9 which is commonly used for recombinant protein production.In the P.xylostella cell lines,expression of three important midgut genes involved in the glucosinolate detoxification pathway,including the glucosinolate sulfatase genes GSS1 and GSS2 and the sulfatase modifying factor gene SUMF1,was detected.The P.xylostella cell lines developed in this study could be useful in in vitro research systems for studying insec-virus interactions and complex molecular mechanisms in glucosinolate detoxification and insect-plant interactions.