POPLAR CLONES EFFECT ON DEVELOPMENT, MORTALITY, AND FECUNDITY OF CHRYSOMELA (= MELASOMA) POPULI L AND CHRYSOMELA-TREMULAE F (COL, CHRYSOMELIDAE)

Larval and pupal survival and development time, adult fecundity and mo rtality of Chrysomela populi L. and C. tremulae F. were determined on 15 clones of Leuce poplars under laboratory conditions (20-degrees-C, 16h/8h photoperiod). For both species, development time of larvae and pupae was the fastest and mortality the lowest on Populus tremula L. x P. tremuloides Michx. clones. Development time of C. populi larvae an d pupae was faster and mortality lower on P. alba L. than on P. tremul a x P. alba. Nearly all C. tremulae larvae fed on P. alba clones died. Mortality of C. populi and C. tremulae adults was lowest on P. tremul a x P. tremuloides clones. C. populi mortality was the highest on P. a lba and intermediate on P. tremula x P. alba. There were no significan t differences between C. tremulae adult mortality on P. tremula x P. a lba and P. alba clones. For both Chrysomela species fecundity was the highest when reared on P. tremula x P. tremuloides. On P. alba, C. pop uli laid very few eggs and C. tremulae laid none. The influence of bot h physical characteristics and chemical composition of the foliage on these results will be discussed.