The research aims to Identify some species of aphids on plant families, and test the
possibility of transfer to the local isolate of Cucumber mosaic virus. Two species of aphids
in bean fields and citrus orchards have been defined, namely: Black be
an aphid Aphis
fabae and Cotton aphid Aphis gossypii, respectively, depending on the specialized
classification keys. The infection proved vital feedback and testing the function using
plants: Nicotiana tabacum and Chenopodium quinoa transfer each of the A. fabae and A.
gossypii local isolate of Cucumber mosaic virus.
The functional and numerical response of Aphidoletes aphidimyza feeding on
different densities of third instar nymphs of cotton aphid Aphisg ossypii on cucumber
leaves was studied in laboratory at a temperature (25 ± 2 ° C) and relative humidity of
70
%. The predator consumed 2.8 ± 0.64 nymph/day, when prey density was 5 adults. The
predator consumption increased with increasing prey density. At 60 and 80 preys the
predator consumed 34.2 ± 5.36 and 36.4 ± 5.72 nymph /Day consequintly.
Ther was a very high significant correlation (r = 0.93) between the number of prey
consumed and the density of prey, So according Holling (1959) model of functional
response, we put A. aphidimyza predator under the third type (type III). The increase of
prey density caused increasing in egg numbers of predator The predator laid eggs in few
numbers 19 ± 4.0 eggs / female when fed on 5 prey /day, and these numbers of eggs laid
by predator increased to 28.6 ± 4.48 egg/female under prey density of 10 prey /day. the
increase of eggs numbers reached to 63.4 ± 6.48 egg/female when prey density was 80
prey/day so we noticed the predator oviposition increased with high prey density, and these
increase caused by increase in predation efficiency and these lead to another kind of
response called numerical response.
