ABSTRACT2 ) 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.

The comparative population growth parameters ofthe two-spotted s pider mite, Tetranychus urticae Koch on cucurbits vegetable crops; Sudan ian, Musk and Snake melons commonly planted in numerous districts ofEgy'pt were studied. These parameters were estimated at 25 ± I°C, 60 ± 5% R.ll. and a photoperiod of 14:10 hrs . (L: D) daily. Developmental t imc , surv ival to adult stage and egg hatchability were similar among the three host plants, hut significant va riation in fecundity and longevity , resulting in large differences tor population growth parameters. such as the intrinsic rate ofnatural increase (r 111 ) , net reproductive rate (Ro) and finite rate of increase(),). were detected. Sudan ian melon was th e most favorable host for the two-spotted spider mite wit h rm (0.297), fi.JIIowcd by Mu s k melon (0.243) ofT s prings/female/day. The s lowest population growth was observed on Snake melon with rm (0.231) off springs/ female /day.

The experiment was carri ed out to estimate the sustainable effect of the acaricides, profenofos, hexythiazox and o:'i nomesifen on offspring of the two spotted spider mite Tetranychus urticae Koch. TI1e estimation was determined -> ing a combination of conventional bioassay of the tested acaricides and life table procedures of the two spotted spider ::1ite. LC25. LC50 and LC90 of profenofos recorded 3.64 , 9.90 and 66.82 ppm, respectively and 6.9, 20.68 and : 67.2 ppm , respectively for hexythiazox; whereas they were 10.46, 57 .5 and 455 .8 ppm,respectively for spinomesifen . The biological aspects, developmental time of mites treated with LC 50 of the tested acaricides, were followed up. Results show that the tested acaricides affected the developmental time of immature stages. Developmental time 2f untreated mites was achieved throughout 6.16 days; whereas it was 7.12, 7.36 and 8.88 days for mites treated 11 ith , profenofos, hexythiazox and spinomesifen, respectively. The tested acaricides showed slight effect on preoviposition period. Survivorship (Lx) varied in their chances to reach adulthood according to the tested acaricide. Fecundity (Mx), the gross reproductive rate (GRR) and net reproductive rate (Ro) were markedly affected by the acaricides. There were no significant differences on the hatchability percentages of laid eggs by treated and untreated femal es and among eggs that were laid at different time throughout the laying period. Data revealed that there were no significant differences among generation time (T) of treated and untreated females. Data showed that untreated mite have the highest intrinsic rate of increase (rm) 0.46 per individual per day; whereas the tested acaricides, profenofos, hexythiazox and spiromesifen enhanced negative intrinsic rate of increase -0.67, -0.74 and-0.7 per individual per day, respectively. Data also showed that the population of the untreated mite, as finite rate of increase (A.), increased daily by 1.58; whereas it was 0.51 , 0.48 and 0.5 times for treated mite with profenofos, hexythiazox or spiromesifen respectively.