THE RELATIONSHIP BETWEEN PLANTING DATES AND SOME CLIMATIC FACTORS ON THE INFESTATION OF EGGPLANT CULTIVARS WITH THE TWO-SPOTTED SPIDER MITE, Tetranychus urticae KOCH.

Abstract

Field studies were carried out at the Experimental Farm, Faculty of Agriculture, Assiut University, during two successive seasons of 2014 and 2015 used three planting dates (early summer, summer and nili plantations) in order to study the relationship between planting dates as well as some of the climatic factors (temperatures and relative humidity) on the census of the twospotted spider mite, Tetranychus urticae Koch on some eggplant cultivars (i.e., black balady, white balady and romy). The results obtained showed that the three tested planting dates gave significant and highly significant differences between mean numbers of T. urticae Koch recorded on the eggplant cultivars. The highest general mean number of T. urticae was recorded on the nili plantation followed by summer and early summer ones during the two growing seasons of 2014 and 2015. On the other side, the Max. and Min. temperatures gave highly significant and significant correlation values on the census of T. urticae through the three tested planting dates. While, the relative humidity showed negative insignificant correlations with the T. urticae census in the early summer plantation and positive significant in summer and nili ones on the three tested eggplant cultivars during 2014 and 2015 growing seasons. It can be concluded that, the planting dates and climatic factors have a strong effect on the rate of eggplant cultivars infestation with T. urticae. Therefore, severe injury of the pest can be avoided by using the early summer plantation date.

PREY CONSUMPTION AND FECUNDITY OF Phytoseiulus persimilis ATHIAS-HENRIOT FED ON DIFFERENT STAGES AND DENSITIES OF Tetranychus urticae Koch. (ACARI: PHYTOSEIIDAE: TETRANYCHIDAE) UNDER LABORATORY CONDITIONS

“…Acarological studies which were carried out in Egypt revealed that spider mites particularly T. urticae may cause remarkable damage to infested different solenaceous crops (El-Saiedy et al, 2015;Abou El-Saad, 2016;Abou Ouf, 2016;Ali et al, 2017). Studies have been conducted in different countries to assess the effect and potential of natural enemies for controlling this pest.…”

“…In 2014, the total areas cultivated with eggplant in Egypt reached 49713 hectares produced approximately 1257913 tons (FAO, 2014). Many authors cleared that one of the factors contributing to low yields is injury caused by many arthropod pests, particularly phytophagous mites that are widely spread during the growing season of eggplant (Adango et al, 2006;Ohno et al, 2012;Azandeme et al, 2015;Abou El-Saad, 2016). Among the http:/www.journals.zu.edu.eg/journalDisplay.aspx?Journalld=1&queryType=Master…”