Plant leaves of six sugarcane varieties; El 264-2, G 84-47, EJ 24-2, EH 87-4, PH 80-13, El 242-16, and
the commercial variety GT 54-9 were evaluated for the rates of infestation with Pulvinaria lenuivalvata
(Homoptera: Coccidae) under field conditions.. Among all tested varieties, PH 80-13 variety showed highest
resistance [lowest infestation rate (9.71 indivhue1s1leaf). On contrary, three varieties, (El 24-2, El 242- 1.6 and G
84-47) were heavy infested (15.88, 16.46 andIl7.50 individuals/leaf respectively), being the highest susceptible.
While, the remaining 3 varieties (EH 87-4, GT 54-9 and El 264-2) could be categorized as intermediate level of
susceptibility (11.25, 13.50 and 14.10 individuals/leaf respectively). Leaf blade anatomical characters showed
identical susceptibility results with the infestation intensity levels. Significantly differences were clearly
recorded between the three previous groups of sugarcane varieties in the anatomical features. Histological
studies of leaves proved that resistance could be attributed to more thickness of leaf blade, width of xylem
vascular bundle and phloem of vascular bundle.
Keywords: Sugarcane varieties, Pulvinaria tenuivalvata, Susceptibility, Histological parameters
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