Relative abundance of the major piercing-sucking pests and their associated natural enemies on coriander plants (Coriandrum sativum L.) in Assiut Governorate

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 %).