FEEDING-BEHAVIOR OF CRYIIIA-RESISTANT AND SUSCEPTIBLE COLORADO POTATOBEETLE (COLEOPTERA, CHRYSOMELIDAE) LARVAE ON BACILLUS-THURINGIENSIS TENEBRIONIS-TRANSGENIC CRYIIIA-TREATED AND UNTREATED POTATO FOLIAGE
Ja. Altre et al., FEEDING-BEHAVIOR OF CRYIIIA-RESISTANT AND SUSCEPTIBLE COLORADO POTATOBEETLE (COLEOPTERA, CHRYSOMELIDAE) LARVAE ON BACILLUS-THURINGIENSIS TENEBRIONIS-TRANSGENIC CRYIIIA-TREATED AND UNTREATED POTATO FOLIAGE, Journal of economic entomology, 89(2), 1996, pp. 311-317
Behavior of Bacillus thuringiensis tenebrionis-resistant and susceptib
le Colorado potato beetle, Leptinotarsa decemlineata (Say), larvae on
cryIIIA-treated, B. thuringiensis tenebrionis-transgenic, and untreate
d foliage was quantified. The behavior of resistant larvae was not aff
ected by cryIIIA on treated leaves. Susceptible larvae exposed to cryI
IIA-treated foliage spent approximate to 2% of the time feeding, where
as susceptible larvae on untreated foliage spent 28% of the time feedi
ng. Resting time for susceptible larvae on cryIIIA-treated foliage was
nearly double resting time on untreated foliage. On cryIIIA-treated f
oliage, resistant larvae spent 11% of the time feeding, significantly
longer than fur susceptible larvae. The behavior of both resistant and
susceptible larvae on B. thuringiensis tenebrionis transgenic leaves
was similar to that of susceptible larvae on cryIIIA-treated leaves. L
arval position on the upper versus lower surfaces of leaves was not af
fected by B. thuringiensis tenebrionis, and did not differ between res
istant and susceptible strains. Our results suggest that larvae resist
ant to formulated B. thuringiensis tenebrionis insecticides may remain
susceptible to B. thuringiensis tenebrionis-transgenic plants that ex
press high concentrations of toxin.