Components of resistance to Liriomyza trifolii in Chrysanthemum morifolium and Chrysanthemum pacificum

Summary In three experiments, Chrysanthemum morifolium Ramat. cultivars and C. pacificum Nakai, were exposed for four days to adult flies of Liriomyza trifolii (Burgess). The flies fed on all plants and laid eggs which were allowed to developed in a leafminer free greenhouse. Feeding level and oviposition varied between genotypes. The largest differences between entries were visible in the percentage of larvae that reached the pupal stage. In the most susceptible C. morifolium cultivar 97% of the larvae pupated against 1% in the most resistant cultivar Penny Lane. C. pacificum Nakai was also resistant with larval survival rates of 12%, 2% and 0% respectively in three consecutive experiments. Breeding prospects and areas for further study are discussed.