LARVAL PERFORMANCE OF 2 LEAFROLLER SPECIES ON KNOWN AND POTENTIAL HOSTS

Two univoltine leafroller species, Archips argyrospila Walker and Arch ips rosana L., were reared from eclosion to adulthood on known or pote ntial host plants. Both species were able to complete development on e ight of the ten plants tested, the exceptions being apricot and peach. Rates of development differed among hosts, and indicated a range of h ost suitability. Differences in female pupal weights were apparent fol lowing the different rearing treatments, but these did not correlate w ith subsequent female fecundity. When development was compared between the two leafroller species, A. rosana had higher survivorship, more r apid development and higher female fecundity than did A. argyrospila, regardless of host. These findings indicate that A. rosana may success fully exploit a wider host range than does A. argyrospila. Comparisons of survivorship and developmental rates among hosts for each species of leafroller suggest that both species may have the potential for hos t-range expansion.