The susceptibility of three varieties of bean, ‘PhaseoIus vulgaris L.)
namely Bronco, Swiss blanc and Giza 3 to infestation with the whitefly (Bemisia
tahaci Gennadius, Homoptera: Aleyrodidae) and aphids (A phis craccivora Koch
and Myzus persicac Sultzcr, Homopicra: Aphididac) was investigated in Qalubia
governorate in 1996 and 1997. Bronco variety was the most susceptible followed
by Swiss blanc and Giza 3 was the least susceptible variety.
A positive correlation existed between whitefly or aphid population on
one hand and sugar and carbohydrate content in the leaves on the other. Aphid
and whitelly populations were correlated with the anatomical structure of the
leaves. Lower infestations occurred on the leaves with thicker spongy tissues.
Giza 3 variety produced the highest seed yield followed by swiss blanc then
Bronco.