الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 177 |  |  |
| | | from | 177 | | |
Abstract
ABSTRACT
This study was conducted in Qalyubia governorate, one of the delta governorates in Egypt, over two successive seasons 2020 and 2021, to studying the survey and population dynamics of aphid species and associated predators on peach, apricot and plum trees.Also,study the effect of constant temperatures (20 – 25 – 30 °C) on some biological aspects of HyalopteruspruniGeof. in the laboratories of the Plant Protection Research Institute in Dokki, Giza Governorate. The obtaind results revealed that thier were two aphid species (Hyalopteruspruni and Myzuspersicae) infested tested trees associateal with 7 predator species i.e, CoccinellaundecimpunctataL.; CoccinellaseptempunctataL.; CydoniavicinaniloticaMuls.; CydoniavicinaisisChrysoperlacarneaStephens; Syrphuscorollae, and Aphidoletesaphidimyza. The mealy plum aphid was the dominat aphid species found infested the three tested trees. The highest mean number (1958.3 individuals/sample) of H. pruni was recorded on apricot at 2nd week of May during season of 2021. The results of biological aspects of the mealy plum aphid under the three tested constant temperatures of 20, 25 and 30 °C reared on apricot seedlings revealed that: the developmental threshold temperature was greater for the nonlinear model than for the linear model. The greatest proportional survivorship of nymphs recorded at 25 ºC., mean daily fecundity was lowest at 30 ºC and highest at 20 ºC. The adult longevity decreased with temperatures decreasing. The population growth rates were estimated as fecundity and development time of tested individuals and were the highest at 20ºC.