Ecological studies on the greedy scale, Hemiberlisia rapax (Comstock) (Homoptera: Diaspididae) on pear trees in burg El-Arab area, Alexandria, Egypt.
The greedy scale, Hemiberlisia rapax (Comstock) causes economic damage on pear trees under irrigation system in Burg El-Arab area (50 Km. West of Alexandria). The infestation rate of H. rapax reached its first maximum rate during August to October, and the second one occurred from January to March. The 1st highest peak of insect population occurred during September and October; the second was during January and February, and the third one corresponded to April for the 1st and the 2nd successive seasons. The statistical analysis was performed to determine the relationship among the weather factors of mean daily temperature, daily relative humidity, wind speed, and dew point in relation to the population activity of Hemiberlisia rapax. The immature stages had two peaks of fluctuation during October to November and July to August. The adult females reached their maximum rates during winter and spring months. Adult males appeared in late March in few numbers. The insect was parasitized by Aphytis diaspidis (Howard) (Hymenoptera: Aphelinidae) in maximum numbers in June and July. This parasitoid had three overlapping generations all the year round. The first in September-October; the second extended from March to May; while the third one lasted from July to September.
Mesbah
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Agricultural Research Centre, Alexandria, Egypt.
Moursi Khadiga
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Mourad
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Abdel-Razak Soad
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D000818:Animals; D001066:Appetite; D017753:Ecosystem; D004534:Egypt; D005260:Female; D006430:Hemiptera / Q000472:pathogenicity* / Q000502:physiology; D008297:Male; D011156:Population Density; D031989:Pyrus / Q000469:parasitology*; D012621:Seasons; D014197:Trees / Q000469:parasitology*