الفهرس 
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Abstract
I-Survey and occurrence determination of phytomites associated with cucurbits under Assiut region condition:-
Occurrence of phytophagous mites associated with cucurbit plants i.e. squash, cucumber, watermelon and pumpkin cultivated at Abou Teeg, El-Badary and Assiut districts, Assiut Governorate were recorded with early summer plantations during the midseasons of 2014 and 2015. At Abou Teeg district, the two spotted red spider mite Tetranychus urticae abundantly occurred with all surveyed cucurbit plants with percentages ranged from 33.2 to 84.8% in 2014 and from 36.4 to 84.0 %, in 2015. The two spotted red spider mite Tetranychus cucucrbitcearum detected with all surveyed crops but with low percentages ranged from 4.0, to 16.8 in 2014 and from 7.2, to 14.8 %, in 2015. Citrus brown mite Eutetranychus orientalis occurred only on cucumber plants by 4% in 2014 while in 2015 it was occurred on cucumber and watermelon by 5.6 and 6.4%, respectively. The broad mite Phyllotetranychus aegyptiacus was detected only on cucumber and pumpkin with low percentages. Occurrence of the broad mite Polyphagotarsonomus latus was detected on the all plants for the both seasons. Abou Teeg was discriminated than other districts by the occurrence of Rhizoglyphus sp. in the most cucumber samples from greenhouses.
Occurrence of phytophagous mites detected at El-Badary district explained superiority of the two spotted red spider mite in occurrence with the all tested cucurbits specially cucumber as the other districts. Citrus brown mite was recorded at El-Badary on the all tested cucurbits with different occurrence percentages with high percentages on pumpkin and cucumber by occurrence percentages of 78.4 and 72.8 % in 2014 while it was 76.8 and 75.2% in 2015. At Assiut district T. urticae, T. cucurbitcearum, E. orientalis and P. latus were occurred in all cucurbit field samples during 2014 and 2015 in different percentages with surpassing of T. urticae than the others, while P. aegyptiacus was detected merely with cucumber and pumpkin. .In general Rhizoglyphus sp. and Tyrophagus sp. disappeared in the surveyed samples from the fields while they appeared in greenhouse samples.
II-Population fluctuation of T. urticae with some cucurbites plants at different plantation periods in Assiut district, Assiut Governorate
A-Population fluctuation of T. urticae with pumpkin plants at Summer and Nili plantation periods in Assiut district, Assiut Governorate
Summer plantation (2014) show that the high populations of T. urticae associated with pumpkin recorded in May and that surpassing significantly the population in March. The calculated correlation values between the mean temperature and number of mite stages were positive recording, 0.5935*, 0.3350, 0.5535* and 0.4090 with eggs, larvae, nymphs and adults, respectively. These values were significant with eggs and nymphs. On the other hand the correlation between the mean relative humidity and the number of mite stages was weak and negative with the all stages
In 2015 the total number of all stages of T. utrticae associated with pumpkin was few, 94 / 25 leaves in the first of season and reached to the highest number 1224 / 25 leaves in the end of the mid-season on 24th May. The counted correlation values between the mean temperatures of all stages were fairly positive recorded with all stages. The regression values between the mean temperatures and the mentioned stages were 13.62, 2.98, 3.82, 27.49 and 51.00 with eggs, larvae, nymphs, adults and total, respectively. On the other hand correlation values between mean relative humidity and the population density were slightly negative with eggs (- 0.3045) and weak negative with larvae, nymphs, adults and total. Regression values between relative humidity and T. urticae population density were -6.98, 0.87, 0.85, -11.74 and - 21.45 with eggs, larvae, nymphs, adults and total population, respectively.
Population density fluctuation of Tetranychus urticae associated with pumpkin in Assiut region during summer plantation date of 2014 and 2015 had been peaked four times.
Monthly average numbers of T. urticae / 25 leaves associated with pumpkin in Assiut region during summer plantation of 2014 and 2015 show that the lowest numbers of all stages were recorded in the first of the plantation season in March and got the highest numbers during May.
In Nili plantation average population density of Tetranychus urticae /25 leaves associated with pumpkin in autumn (Nili) plantation date 2014 was nil with egg stage on 14th and 21st September. Larvae were in lowest number recording nil on 14th and 21st September. Nymphs disappeared on 6th July, 7th, 14th September and 21st September. Adult stage recorded the lowest number in the first of Nili plantation. Results indicate that the highest population density that significantly differed than other densities of eggs, nymphs and adults were in August month on 3rd, 10th and 10th August, respectively. Larvae number clearly increased significantly on 13th July. Population of T. urticae eggs or adults in Nili plantation 2014 peaked five times
Simple correlation value between the number of eggs and the mean daily temperature was fairly positive and significant at (P=0.05) with egg and larval stages as well as the total
Nili plantation of 2015 shows the disappearance of eggs and larvae on 14th and 21st September, while nymphs were concealed on 6th July, 14th September and 21st September. The highest population density of T. urticae eggs, larvae, nymphs and adults was attained in July 2015 on 20th July for eggs and on 27th July for the rest of stages (larvae, nymphs and adults).Population of T. urticae eggs or adults in Nili plantation 2015 peaked four times. Correlation between number of T. urticae and the corresponding mean daily temperature were non-significant with all stages by slightly positive with eggs and nymphs and fairly positive with larvae and adults. The estimated regression between the mean temperature and T. urticae were 6.54, 3.15, 2.30, 22.43 and 37.39 with eggs, larvae, nymphs, adults and total, respectively
Simple correlation values between the number of T. urticae and the daily mean of relative humidity was negative and non-significant with egg, larval, nymphal stages except with adult stage it was significant. Regression values estimated between T. urticae numbers and mean relative humidity were -8.57, -3.69, -1.65, -28.35 and -31.49 with the successive stages and total, respectively.
B-Population fluctuation of T. urticae with cucumber plants at summer, Nili and winter plantation periods in Assiut district, Assiut Governorate
With cucumber summer plantation 2014 the total high population of T. urticae had estimated on 10th May. Simple correlation between number of eggs, larvae, nymphs, adults and total with mean daily temperature were positive with all stages and total while it was highly significant with adults, recording 0.5006, 0.4685, 0.3496, 0.6780** and 0.5192, respectively. Simple correlation values between number of T. urticae and the daily mean relative humidity were negative recording -0.0592, -0.1664, -0.1865,- 0.2052 and -0.1221 with eggs, larvae, nymphs, adults and total, respectively. Population fluctuation curve of T. urticae during 2014 illustrated the occurrence of five peaks of eggs but adults peaked six times.
Population of T. urticae during summer plantation of 2015 behaved in similar trend as in 2014. The total high population had estimated on 10th May. Simple correlation was fairly positive with eggs and high significant positive correlation with the rest. Simple correlation between the population of T. urtica and relative humidity were negative with all stages. Monthly average number of T. urticae associated with cucumber in summer plantation 2014 & 2015 that recorded high populations in June.
In Nili plantation the highest population for eggs (101 / 25 leaves) was recorded on 5th October 2014 while larvae recorded high number 41/ 25 leaves on 2nd November. Other stages nymphs and adults as well as total gave high numbers 30.5, 72.5 and 206 / 25 leaves, respectively. Population curve show four peaks for all stages that meaning the occurrence of four generations of T. urticae in Nili plantation period. Simple correlation values between T. urticae number and mean daily temperature were non-significant and weakly positive with all stages except nymphs that was fairly positive. Also partial regression values with mean daily temperature were weakly positive with all stages. Mean relative humidity percentages effect negatively on the population of T. urticae during Nili plantation with weak effect on larvae and adults but on eggs and nymphs it correlated fairly negative. Also partial regression values were feeble and negative effect.
Population of T. urticae in 2015 Nili plantation of cucumber reached the high population for eggs, 90 / 25 leaves on 5th October, while with adults and the total population seemed to be at the high level on 19th October but larvae and nymphs increased nearly at the end and in the beginning of this plantation period, respectively. Simple correlation values with mean daily temperature was negative and non-significant with all stages of T. urticae in this plantation period while correlation with the mean relative humidity was positive and non-significant with larvae and nymphs, however eggs and adults significantly correlated positively. Population curve exhibiting four peaks for all stages of T. urticae in cucumber Nili plantation 2015.The high population of the T. urticae all stages with cucumber Nili plantation 2014 and 2015 had been occurred in October except larvae that appeared in high population in November
Winter plantation of cucumber 2014/ 2015 harbored few numbers of T. urticae stages. The highest number 58 was recorded with eggs at the end of plantation period in 8/ 3/ 2015 followed by 52 adults/ 25 leaves recorded in the same time. Population of all stages peaked three times that mean the occurrence of three generations during winter plantation. This plantation period also distinguished by the positive significant correlation with the mean daily temperature recording highly significance with eggs, larvae and the total as follows 0.6567**, 0.8057** and 0.7439**, respectively. On opposite correlation with the mean daily relative humidity was negative recording -0.2812, -0.4302, -0.2567, -0.4632 and -0.4676, with eggs, larvae, nymphs, adults and the total. The population fluctuation of T. urticae on cucumber during winter plantation of 2015/2016 was at high level at the final of this plantation period on 8th March recording 62, 44, 24 and 61 with eggs, larvae, nymphs and adults, successively. We can also distinguish three peaks of T. urticae population in this season on 30th November 2015, 1st February and 8th March 2015.
As mentioned above with 2014/ 2015 the correlation with mean daily temperature and T. urticae population was positive and highly significant with all stages during winter plantation of 2015/2016, recording 0.5887, 0.7737, 0.6434, 0.7706 and 0.8439 with eggs, larvae, nymphs, adults and total, successively. On opposite this result the correlation with mean relative humidity was negative with all stages.
The monthly average number of T. urticae associated with cucumber during winter plantation 2014/ 2015.also 2015/2016 indicate dropping in the population remarked in December with the increase in the starting and the ending of winter plantation in November and March. General mean number of T. urticae recorded with cucumber during winter, summer and autumn (Nili) plantations during 2014/2015 and 2015/2016 illustrated that the population of T. urticae descended from summer to winter e.g. the recorded average number of adults were 120.9, 40.5 and 30.2 of 2014/2015, in opposite to 133.9, 35.9 and 33.0 in summer, autumn and winter of 2015/2016, respectively.
C-Population fluctuation of T. urticae with squash plants at summer, Nili and winter plantation periods in Assiut district, Assiut Governorate
Average population densities of T. urticae / 25 leaves of squash in summer plantation 2014 under Assiut district condition exhibited the total highest number of T. urticae 407/ 25 leaves on 10th May. All stages peaked six times. All stages correlated positively with the mean daily temperature but negatively correlated with mean relative humidity. Summer plantation of 2015 revealed the high number of T. urticae on squash on 10th May, so total numbers recorded the high number 398.0 on 10th May. Also it was obvious that there were six peaks could be recorded with the population curve of T. urticae during 2015. The correlation with mean temperature was positive and non-significant with all stages except with eggs the correlation was positive and significant. In opposite the correlation with relative humidity was negative with all stages. The high average monthly numbers of eggs, larvae, nymphs and adults were in June of 2014 and 2015.
Nili plantation of squash 2014 exhibited four peaks of T. urticae population. It was observed that the high population with all stages realized on 19th October. Correlation between T. urticae population and mean daily temperature was weak, positive and non-significant with all stages. In opposite the correlation with mean relative humidity was negative and non-significant with all stages except with eggs. In Nili plantation of 2015 T. urticae increased at four peaks. Simple correlation values with mean temperature were positive with recording high significant 0.6657** with larvae and significant with eggs, nymphs and adults recording 0.5589*, 0.5352*and 0.5482*, respectively. In opposite this result the estimated correlation values with the mean relative humidity were negative and significant (0.5992* and 0.5770*) merely with eggs and nymphs.
Winter plantation of squash 2014/2015 and 2015/2016 revealed low population densities with three peaks also revealed high positive and significant correlation between the mean temperature and T. urticae numbers (0.6934** and 0.6297**) with eggs and larvae but it was positive and non-significant with nymphs and adults. Simple correlation with the mean relative humidity displayed negative trend with all stages by non-significant effect.
Average monthly number of T. urticae during winter of 2014/2015 as well as 2015/2016 indicated the excelling of the population in March than other winter months.
III-Evaluation of some acaricides against T. urticae on cucumber
Evaluation of some acaricides against T. urticae associated with cucumber under El-Badary district, Assiut Governorate conditions indicated that the highest average efficiency of the tested acaricides was after three days from application surpassing the initial effect after one day, recording reduction percentsges of 67.0, 95.0, 50.5, 90.0, 92.0 and 45.0% with Nissorun (hexithiathox 5%), Vapcomic (abamectin 1.8%), Mospiulan (acetamiprid 20), Ortus Supper (fenpyroximate 5%), Abamex (abamectin 1.8%) and Pest (imidacloprid 25%), successively. After ten days from application reduction percentages were 58.5, 89.5, 45.5, 87.5, 86.0 and 40.5 % with Nissorun, Vapcomic, Mospiulan, Ortus Supper, Abamex and Pest, successively. These results mean the surpassing of Vapcomic (abamectin) and retreating Pest (imidacloprid) for controlling T. urticae mite.