الفهرس 
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Abstract
The green peach aphid, Myzus persicae (Sulzer) (Homoptera: Aphididae), is regarded as one of the
major and most destructive pest of vegetable crops in Egypt. The current study carried out during
three successive seasons (2014, 2015 and 2016) in Fakous district, Sharkia Governorate on potato
and pepper fields. The main objectives and results are presented as follows: 1) Survey and seasonal
abundance of aphid species infesting potato and pepper plants, and their aphidophagous insect
predators. Pepper plants were severely infested with aphids compared to potato plants. Three aphid
species of Myzus persicae (Sulzer), Aphis gossypii Glover, and Aphis craccivora (Koch) were found
infesting potato plants, while only the first two species were recorded on pepper plants.
Aphidophagous insect predators found to be associated with aphids infesting both potato and pepper
plants were belonged to three insect orders of Coleoptera, Neuroptera and Diptera. Besides, the
predators of order Hemiptera, found only associated with aphid-infested pepper plants. 2)
Biological aspects and predation efficiency of the eleven-spotted ladybird beetle, Coccinella
undecimpunctata L. (Coleoptera: Coccinellidae) fed on green peach aphid, M. persicae colonized
on potato plants under laboratory conditions. The average durations of the 1st, 2nd, 3rd and 4th larval
instars of C. undecimpunctata were 3.0, 3.07, 3.1 and 3.4 days, respectively. The mean
consumption during larval stage was 254.03 aphids per larva. The 4th and 3rd larval instars of C.
undecimpunctata were the most efficient as their respective consumption was 36.50 and 28.32% of
the total consumed aphid preys during the whole larval duration. The adult female of C.
undecimpunctata consumed about 2.7 times as much as consumed by its larva. 3) Efficacy of four
biorational compounds (Skanmite, 73% EC, Spiner 10% SC, Agreflex 18.6% SC and Protecto 9.4%
WP) against aphids infesting potato and pepper plants using three ascending application rates (half
dose, full recommended dose, 1½ dose) under field conditions. All tested compounds at their
different rates caused noticeably reduction in aphid population. Highest reduction was recorded in
Agreflex using full dose at 84.18 and 86.29% in potato and pepper plants, respectively. Brotecto at
full dose came second at 80.73 and 81.08% reduction on potato and pepper plants, respectively.
Skanmite had moderate efficiency even with using half dose at 76.58% reduction in infestation on
potato plants. The lowest reduction in aphid infestation was recorded in Spiner treatments. 4)
Impact of certain biorational insecticides used to control aphid infestation on the aphidophagous
predators (Coccinella undecimpunctata L. and chrysopa carnae). Based on LC50, the descending
order of toxicity was skanmite > agreflex > spiner. Therefore, spiner treatment was relatively safe
for larvae and adults of C. undecimpunctata and larvae of Ch. Carnea than skanmite and agreflex.