To evaluate the impact of drought stress on the incidence of certain arthropod pests and their associated predators which inhabit cowpea plantations, field tests were conducted in two different levels of irrigation (10-and 20-day intervals) by using five newly produced cowpea cultivars. Results indicated that the main piercing and sucking pests Bemisia tabaci (Genn.) and Tetranychus urticae Koch. were represented in high numbers in stressed plantations when compared to non-stressed ones. On the other hand, the common predators associated with these pests had not been affected by these irrigation differences. Regarding to the damage percentage caused by the pod borer pest Etiella zinckenella Treitschke, an obvious increase was recorded on stressed plantations than on the normal irrigated ones in most of the tested cultivars. At harvest, the obtained results indicated an obvious decrease in the net yield income of all the tested cultivars in the stressed irrigated area than in normal irrigated one. Therefore, it must be recommended to irrigate cowpea plantations by at least 10-day intervals to avoid the high infestation by both of the sucking pests and pod borers, and also, to obtain high and good yield income.
Fourteen okra varieties were tested in Assiut governorate to estimate their fruit infestation degrees caused by the spiny bollworm Earias insulana (Boisd.) and to determine their susceptibility degrees against this insect pest. Irany, Red base and Balady 4 okra varieties recorded the highest infestation values with an average of 11.92% > 10.40% > 9.13%, respectively. However, Oraby, Balady 5 and Balady 6 okra varieties recorded the lowest values with an average of 6.93% > 6.79% > 6.75%, respectively, as an average of the two successive seasons of 2009 and 2010. The highest infestation was recorded during the last three weeks of August. Dependent on the mean numbers of (Bores + larvae), the tested varieties revealed different susceptibility degrees to the pest. Balady 5 and Balady 6 varieties harboured the lowest numbers and appeared as highly resistant (HR) varieties. The remaining varieties revealed different susceptibility degrees to the pest. Negative correlation was recorded between the numbers of hairs presented on fruit surface of both Balady 5 and Balady 6 varieties and the pest infestation. Therefore, okra varieties that showed some sort of resistance can be included among advanced breeding programs to select new varieties resistance to E. insulana.
This work aimed to identify the olive insect pests and their associated natural enemies recorded in Egypt by using the available literatures. Determination of the mites associated with olive groves is also took a beam of light. The collected articles exhibited the presence of 15 hexapod species belonging to 14 genera, 9 families and 4 orders in association with olive groves. Three predatory Acarid species were also recorded. The obtained data clear that, 60% of the recorded arthropod pests were belonging to order Homoptera. However, 20%, 13.33% and 6.67% of the recovered species were belonging to orders Lepidoptera, Diptera and Coleoptera, respectively. Fifty five parasitoid species belonging to 9 Hymenopteran families were recorded in association with arthropods infesting olive trees. The obtained data showed that 30.90% of the total identified parasitoid species were belonging to family Aphilinidae. It followed by family Encyrtidae by (27.27%). The remaining families can be arranged in descending order as follows: Pteromalidae by 10.91% > Braconidae by 9.10% > both of Euritomidae and Trichogrammatidae by 7.27% > Eupelmidae by 3.64% > both of Bethylidae and Chalcididae by 1.82%. The role of biological and chemical control procedures used to manage olive pests was determined. Parasitism of certain parasitoid species on the main olive arthropod pests was investigated. The impact of chemical and safe alternative compounds to reduce olive pests and their associated natural enemies has been discussed in more details.
Faunistic composition and seasonal abundance of certain sap-sucking species inhabiting tomato and cucumber plantations were determined by using sweep net and direct count methods, during summer seasons of 2015 and 2016 in Assiut Governorate, Northern Upper Egypt. Twelve species belonging to 8 families and 3 orders in addition to the acarid mite were recorded. Heteropteran species were found to be constituted 69.24% of the gathered species. However, Homopteran species were found to be constituted 15.38%. Thysanoptera and Tetranichidae were presented by 7.69% for each. Concerning to the sampling method, 76.92% of the collected species were captured by the sweep net method, while 23.08% were gathered by the direct count method. The recovered species were classified as predominantly predaceous, predominantly phytophagous, predaceous in part and phytophagous in part species. Seasonal abundance of the recorded species was determined. The distinct predators, Coranus aegyptius (Fabricius, 1775) and Orius spp. showed relatively low abundance percentages. The predatory-phytophagous mirid species [Campylomma unicolor Poppius, 1914; Nesidiocoris tenuis (Reuter, 1895); Creontiades pallidus (Rambur, 1839). and Deraeocoris serenus (Douglas & Scott, 1868)], showed different abundance percentages. Amongst these taxa, N. tenuis revealed the highest abundance percentage on tomato plantations with an average of 63.00 and 75.00% during 2015 and 2016 seasons, respectively. The distinct phytophagous species, Thrips tabaci Lindeman, 1889; Bemisia tabaci (Gennadius, 1889) and Tetranychus urticae Koch, 1836 presented the greatest abundance percentages on cucumber when estimated by the direct count method. So, this work can be reflect the importance of sweep net as a suitable sampling method for determine the faunistic composition of the flight predatory insects inhabiting tomato and cucumber. However, direct count can be consider the most suitable method for determine the population trends of mobile or non-mobile arthropods inhabiting the same crops. Also, use of more than one sampling method could be successful to clarify the relation between useful and harmful arthropod species.
Africanized and European (A. mellifera carnica) honey bees to Varroa-infested brood in tropical areas was also investigated. An annotated list contains scope of study, authors and the studied area was concluded.
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