METHOD: Life Cycle CONDITIONS: Green House - 16h light at 22-27C and 40-60% RH METHOD NARR: Larvae were confined on leaves and allowed to feed. Fourth instars were monitored closely and removed from the cages to pupate. Develop were calculated and weight was measured. Groups of adults were isolated on plants and cages were monitored daily, egg masses removed and # of eggs per mass determined. RESULTS NARR: Mortality of adults, larvae and pupae on tbr. Duration of pupation on ber was greater than on tbr. Tbr reared females produced more eggs than those on ber. Averaged over all generations, net replacement rates on ber were 80% less than on tbr. AUTHOR EXPLANATIONdaptation of CPB to resistant potato genotypes is unlikely to occur as rapidly as previously reported.