ABSTRACT
The present work was carried out at Shotb and Abnoub locations, Assuit Governorate, Upper Egypt throughout two successive coriander growing seasons, 2011/2012 and 2012/2013.The obtained results showed that coriander plants harbored 55 and 43 insect species belonging to 41, 31 families and 9, 9 orders in shotb and Abnoub locations, respectively. Among these species, [29, 26]; [6, 4]; [7, 4] and [16, 11] were recorded as pests, predators, parasitoids and pollinators and visitors in Shotb and Abnoub, respectively. The order Hymenoptera had the highest number of species [16, 13, species] followed by Diptera [9, 9 species] in both Shotb and Abnoub, respectively. Results also indicated that, regardless of the seasons, aphids [different species] were the most abundant piercing-sucking insect pests on coriander plants, representing 59.00 and 83.14 %, followed by T. tabaci which represented 38.12 and 15.57 % of the grand total of sucking pests. The Empoascae spp. and Campylomma spp. were less abundant and represented only an average of 2.09 and 0.09 % for Empoascae spp. and 1.10 and 1.19 % for Capylomma spp. of the grand total of piercing-sucking pests in Shotb and Abnoub locations, respectively. Concerning the relationships between abiotic and biotic factors with the aphid populations, results also indicated that the studied variables were together responsible for 58.49 % of the aphid population changes in Shotb location, while 64.57 % were recorded in Abnoub location. The change of the aphid populations varied with the plant age [23.46 and 39.73 %], maximum temperature [20.34 and 12.16 %] and natural enemies [4.76 and 4.21 %] in Shotb and Abnoub locations, respectively. Minimum temperature was found to be related with the population of aphid species only in Abnoub location [7.28 %]
ABSTRACT
Thirteen cultivars of canola were subjected to evaluate the percentage of parasitism on cabbage aphid, Brevicoryne brassicae L. infesting canola plants in the field and laboratory during 2011 season in Assiut Governorate. The rate of parasitism in the field was [7.13%] for all cultivars. The rate of parasitism of the aphid collected from the field and reared in the laboratory was 2.67% times higher than the rate of parasitism in the filed at the end of season regardless the canola cultivars. The highest rates of parasitism were recorded with the early ripening cultivars, while the lowest ones were realized with the late ripening cultivars. In the field, the rate of parasitism increased progressively during the third week of February to a peak level [parasitism 43.15%] in the second week of March. Whereas in the laboratory, the highest rate of parasitism [53.06%] was achieved during the last week of February and then the parasitism started to decrease gradually during March. Two primary parasitoids species [Diaeretiella rapae McIntosh and Praon necans Mackauer, Aphidiidae] and two hyperparasotoids species [Alloxysta sp., Cynipidae and Chalcids sp., Chalcididae] were associated with cabbage aphids in canola fields. D. rapae consider the most important primary parasitoids on B. brassicae which represented about 93.93% of the total primary parasitoids in canola field. While, Alloxysta sp. was the most hyperparasioid represent 81.67% of the total of the secondary parasitoid. However, the primary parasitoids recorded the most percentage [71.94%] comparison with the percentage of secondary parasitoids [28.06%] from the total parasitoids for primary and secondary parasitoids