POPULATION DENSITY OF PHYTONOMUS VARIABILIS HRBST. AND PHYTODECTA FORNICATA BRUGG. ON MULTIFOLIOLATE AND TRIFOLIOLATE ALFALFA IN RELATION TO ANATOMICAL CHARACTERISTICS ON THEIR LEAVES
Two alfalfa cultivars - the multifoliolate “Mnogolistna 1” and the trifoliolate “Europe” were investigated for their resistance towards two main alfalfa defoliators Phytonomus variabilis Hrbst., 1795 and Phytodecta fornicata Brugg., 1873. The results of the two year study showed that the population density of both pests was higher in the“Mnogolistna 1” fields. The anatomical study of the leaves showed that multifoliolate alfalfa cultivar has narrower palisade and
spongy parenchyma and thinner leaves and cuticle which make it less resistant to Ph. variabilis and Ph. fornicata.
