3210

3145

كارشناسي ارشد

﴿حشره شناسي﴾

اصفهان:دانشگاه صنعتي اصفهان،دانشكده كشاورزي

1384

شانزده، 129،[II] ص:جدول، مصور،نمودار

ص.ع.به فارسي و انگليسي

رحيم عبادي، حسين سيدالاسلامي

بيژن حاتمي، خورشيد رزمجو

جهانگير خواجه علي، نعمت اله اعتمادي

مهندسي كشاورزي

ID3145

به فارسي و انگليسي:قابل رويت در نسخه ديجيتالي

Abstract In many cases aphids are the most important pests of alfalfa Regarding the importanceof the aphids and little knowledge about their biological control on alfalfa in Iran it wasessential to perform a more complete investigation on identification of alfalfa aphids andtheir natural enemies in Isfahan This investigation was conducted to identify alfalfa aphidsand their natural enemies study on population fluctuation of their dominants species and toinvestigate the effect of alfalfa strip harvesting on their population density in Isfahan Inorder to collect alfalfa aphids and their natural enemies sampling was done from about 30alfalfa fields in Isfahan province in different intervals for two years Investigation onpopulation fluctuation of alfalfa aphids and their natural enemies and also the effect ofalfalfa strip harvesting on population density of aphids and their natural enemies werecarried out in a 2 hac of alfalfa field In this study 4 species of alfalfa aphids and 59 speciesof their natural enemies including 46 predators 11 parasitoids and 2 parasitic mites wereidentified Population density of Acyrthosiphon pisum and Therioaphis trifolii increased inJune and then decreased in July and August but reached at peak in October and November Population density of alfalfa aphid natural enemies were increased followed by increase ofalfalfa aphids density Mass multiplication of Hippodamia variegata Nabis spp andGeocoris spp occurred in October and November and Mass multiplication of Deraeocorisspp Orius spp and parasitoid wasps occurred in June After harvesting of tall alfalfastrips in alfalfa strip harvested field aphid natural enemies such as H variegata Nabisspp Deraeocoris spp and Orius spp moved to adjacent taller alfalfa strips andsignificantly increased on them but the movement trend of Geocoris spp from harvested toadjacent taller alfalfa strips were not in a logical order In many cases the number ofAcyrthosiphon pisum and Therioaphis trifolii in alfalfa conventionally harvested field weremore than strips with same height of alfalfa in strip harvested field The effect of naturalenemies in reduction of Therioaphis trifolii were more than reduction of Acyrthosiphonpisum From the results of this study we can conclude that in contrast to the conventionallyharvested alfalfa field in strip harvested field the density of aphid natural enemies weremore and aphids were less

رحيم عبادي، حسين سيدالاسلامي

بيژن حاتمي، خورشيد رزمجو

جهانگير خواجه علي، نعمت اله اعتمادي