An insect cell line capable of growth in serum-free media and secretion of high levels of recombinant proteins, including virus-like particles, upon infection with recombinant baculoviruses, is provided. Methods involving clonal selection processes, serum-weaning and recombinant protein secretion selection are used to create the insect lines of the invention. This cell line supports replication of baculoviruses, serves as host substrate for baculovirus plaque assays, provides a source of insect proteins, acts as a depot for cell transfection to produce recombinant baculoviruses, and express viral recombinant proteins. Extracellular and intracellular viral recombinant proteins and virus-like particles expressed from this cell line are useful as pharmaceutical compositions, vaccines, or diagnostic reagents.