Climate change could profoundly affect the status of agricultural insect pests. This study predicts expected peach fruit fly (PFF) annual generations under current and future climate by using the accumulated thermal heat units expressed as degreedays unit (DDU). We evaluated how temperature expected to influence the annual generation numbers in three governorates of Egypt using the climate change data output from the HadCM3 model for A1 scenarios proposed by the Intergovernmental Panel on Climate Change. Results indicated that PFF in Asyout have the highest number of possible generations as compared to other locations (North Sinai and EL Beheira) under current climate to be 8 compared with 6 and 7 for other locations, respectively. Generation numbers of PFF under climate change conditions would be increased especially in Asyout governorate to 9 and 10 by 2050 and 2100, respectively. However, the expected generation numbers of PFF at 2050 and 2100 will be 8-9 and 9-10 generations per year for other two locations, respectively.

Bacterial spot caused by Xanthomonas campestris pv. vesicatoria is an important bacterial diseases of pepper and tomato. The present work was planned to record the disease incidence under protected agriculture and open field conditions in different localities of Nile Delta. Also to study the relationship between environmental factors (average daily temperature and relative humidity) and disease severity. The results showed that the open fields were free from the disease during the growing seasons of 2007-2009. Under the protected agriculture conditions, the disease was shown in all surveyed localities. The highest disease severity was recorded in El-Khatatba, El-Fayoum and El-Salhia regions, while it was moderately shown at El-Bosaily; Gazera-El-Dhab, Kha and El-Giza region. However, the disease severity on pepper increased with increasing the average of daily temperature and relative humidity. The disease was sever in the growing seasons 2007-2008 and less in 2008-2009 seasons and this phenomena probably due to the change in the climate between the two different seasons.

L (cv. Samara) covering soil ecosystems population densities Bemisia tabaci Frankliniella intonsa Tetranychus urticae Maximum temperature Minimum temperature soil temperature relative humidity Field trial was conducted during two successive seasons on 2015 and 2016 at greenhouse experimental area, Dokki, Giza Governorate. This study aims to evaluating the efficiency of different colors mulch and some environmental factors on reduction of population density to the main sapsucking pests infesting cucumber and yield. The trial were used five colors mulch to covering soil, i. e., red, green, blue, white, yellow and Control treatment without mulch. The results revealed that there are significant differences between using colors mulch with population densities of some pests the whitefly, Bemisia tabaci (Genn.), the thrips, Frankliniella intonsa(Trybom) and the spider mite, Tetranychus urticae (Koch). The tested mulch colors could be arranged according to population density of pests into six ecosystems. The red and white colors was the most potent treatments in low population pests in cucumber plants followed by blue, control, yellow and green which was the highest mean number of infestation in both seasons. Maximum and Minimum temperature were showed insignificant positive effect in first season but Minimum temperature was showed significant positive on B. tabaci (egg and nymph) during second season. Maximum and Minimum temperature were showed insignificant positive effect with F. intonsa and T. urticae (egg and immature) at the both seasons. The relative humidity had insignificant negative effect on B. tabaci, F. intonsa and T. urticae at the both seasons. The soil temperature had insignificant negative effect on B. tabaci, F. intonsa and T. urticae at the both seasons. The combined effect (E.V) of these ecological factors on B. tabaci (egg and nymph) , F. intonsa and T. urticae (egg and immature) showed that these factors were responsible as a group for 94 % , 79 %, 83, 89, 98, 87, 99, 99, 93, 95 effects on the population dynamics of pests throughout both seasons, respectively. Especially infestation pests-Yield relationship, the mulch colors affect 75% and 82% in yield weight both seasons. Recommendation: the paper recommendation by cover soil surface with red and white mulch to reduce population of whitefly, thrips and red mite and increase yield.

In the present study, the infectivity of the three entomopathegnic nematodes, Steinernema feltiae, Steinernema riobrave and Heterorhabditis bacteriophora, on the cotton leafworm, Spodoptera littoralis was studied. Moreover, the effect of these pathogens on certain biochemical and physiological aspects of the host was also studied. H. bacteriophora, appeared to be more pathogenic than S. riobrave and S. feltiae to the S. littoralis larvae. The highest production (7000 infective juveniles) was obtained, where infective juvenile production from cadavers infected with H. bacteriophora was higher than that produced from cadavers infected with S. riobrave and S. feltiae. The principle nutrients (total protein, carbohydrate and lipid) of the host larvae were highly decreased post-infection with the nematodes S. riobrave and H. bacteriophora. The activity of some larval enzymes was also affected due to infection by these nematodes. Thus, the activity of carbohydrate hydrolyzing enzymes (amylase, invertase and trehalose) changed depending on the species of the pathogen and the enzyme. Amylase activity decreased with the infection by H. bacteriophora, and the reverse was obtained with the infection by S. riobrave and S. feltiae where such activity increased. Invertase and Trehalase activity increased with the infection by three nematode species. The highest increase was obtained in case of infection by S. riobrave. Activities of acid and alkaline phosphatases increased due to infection by S. riobrave, H. bacteriophora. The only exception was a non-significant decrease in the alkaline phosphatase activities of larvae infected with S. feltiae. Whereas, the activity of transaminases (GOT and GPT) was highly decreased with the infection by H. bacteriophora and S. riobrave.