The cucurbits; Sudanian watermelon, Sitrullus lanatus var. colocynthoides, Snake watermelon, Cucumis melo var.
flexuous and squash, Cucurbita pepo L. were checked weekly to get relationship between the infestation with the twospotted
spider mite, and certain chemical and morphological leaf characteristics. The experiment was carried out in two
districts; Bahar El-Bakar; south Port Said governorate and El-Hosainia plain, north El-Sharkia governorate; throughout
the two successive growing seasons 2007 and 2008.The population of the mite Tetranychus urticae Koch varied
according to the crop, season and district. Peak of infestation (29.4 individual/inch2) occurred in July,2007 and
(31.1 indiviuals/inch2) in July,2008.The morphological characteristic cleared that Sudanian watermelon has thick
hairiness leaves compared with those of Snake watermelon (hairy), whereas Squash leaves are nearly hairless. Chemical
determinations of protein, carbohydrates, fats and crude fiber were (10.3, 70.1, 2.7 and 6.3 %) in Sudanian watermelon,
(9.1, 56.7, 1.6 and 15.1%) in Snake watermelon and (7.2, 58.1, 1.5 and 15.4%) in Squash, respectively. Mite population
positively correlated with increasing nutrient contents of leaves e.g. as crude proteins, crude fats, and carbohydrates and
leaves hair.