الفهرس 
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Abstract
SUMMARY
The aim of present work was to collect information that would help
to design a successful integrated pest management programe for the
purple scale insect (Lepidosaphes beckii , Newman) in Egypt. The scope
of the study included the seasonal fluctuations of the population size of
L. beckii on 9 different species and varieties of citrus. The comparative
and relative responses of purple scale insect, L. beckii and its stages to
certain scalicides, i.e. Sumithion, Basudin and Mesrona oil in laboratory.
The bioresidual efficacy of certain scalicides against L. beckii in field on
navel orange trees were also studied. Moreover the phytotoxicity of
certain scalicides on navel orange trees and the effects of these scalicides
on orange fruit yield were determined. Finally, the residues behaviour of
the applied scalicides in summer in orange fruits at harvest time were also
determined. The obtained results could be summarized in the following:
I. The seasonal abundance of purple scale insect,
Lepidosaphes beckii on different species and varieties of
citrus during the two seasons (1994/95 and 1995196):
1. The seasonal abundance of L. beckii on Sour orange trees:
During the two years of investigation the results showed that Lbeckii
had six peaks throughout the first season, these peaks were detected in the
1st. week of April, 4th. week of May, 4th week of July, 3rd. week of
September, 2nd. week of November and 2nd. week of December showing,
497.3, 592.4, 459.5. 472.6. 227.1 and 399.6 individuals 1100 in2
respectively. The lowest population recorded in the 4th week of
November (212.3 individualsllOO in2). During the second season seven
peaks were recorded in the 1st. week of April, 1st. week of May, 4th.
week of June, 4th. week of July, 4th week of October, 2nd. week of
January and the 1st. week of February, showing, 336.9, 316.0, 294.2,
240.1, 311.0, 334.4 and 422.6 , individuals /100 in2, respectively. The
lowest population was recorded in the lst. week of September (209.6
individualsl 100 in2.) . Data, also. showed that the total population of
purple scale on sour orange was higher (399.8 individuals 1100 in2) in
the first season than in the second one (294.1 ind./100 in2.). This showed
the direct influence of the environmental and biological factors on the
purple scale density. Data also indicated of abundance of the two stages
(nymphs and adult females) was usually supported by simultaneous peaks
of abundance of the female stage.
2-The seasonal abundance of L.beckii on Clemantine mandarine trees:
Throughout the first season ( 1994/95), L.beckii had 7 peaks.They
were recorded in the 4th. week of May, 4th. week of June, 2nd. week of
August, 3rd. week of September, 4th.:.. week of October, 4th, week of
December and 4th. week of January.being in respective by 86.9, 55.7,
110.3, 92.6 , 53.6 142.5 and 787.3 individuals 1100 in2. were counted,
respectively.The lowest population was recorded in the 2nd. week of
December (26.1 individuals 1100 in2.). While, in the 2nd season, the
purple scale insect had 6 peaks in the 3rd. week of May, 4th. week of
June, 1st. week of September, 2nd. week of November, 4th. week of
December and 3rd. week of February, being, 65.8, 119.8, 188.1, 38.6,
44.5 and 187.4 individuals 1100in2. respectively. The lowest population
was recorded in the 2nd. week of December (34.0 individuals 1100 in2) .
The results also, showed that peaks of abundance of the total stages were
supported by simulataneous peaks of abundance of the females or
nymphs.
3- The seasonal abundance of L.beckii on Balady mandarine trees:
In the frist season, (1994/95), the highest densities of L. beckii on
Balady mandarine were recorded in the 3rd. week of March, 1st. week of
May, 2nd. week of June, 4th. week of July, 4th. week of August, 2nd.
week of November and 3rd. week of February, being in respective by,
92.9,61.1 ,67.3 ,93.6 , 125.7,53.9 and 135.6 individuals 1100 in2.. While
the lowest population was recorded in the 3rd. week of May (46.8
individuals / 100 in2.). In the 2nd season, the highest numbers of L. beckii
were recorded in the 3rd. week of May, 2nd. week of June, 1st. week of
August, 2nd. week of November and 3rd. week of February, showing,
87.6 , 290.1, 190.3, 49.8 and 95.4 individualsl 100 in2., respectively.
While, the lowest population of it was recorded in the 4th. week of
December (38.9 individuals 1100 in2).
In the first season, peak of nymphs abundance occurred
simultaneously during peak of abundance of total stages, while peaks of
abundance of total stages of L. beckii on Balady mandarine were usually
either supported with coincident peaks of the nymphal stage or female
peaks that preceded it. In the second season, females and nymps peaks
supported the peaks of abundance of the total stages.
4- The seasonal abundance of L. bee1cii on Persian lime trees:
On Persian lime trees the purple scale had seven peaks of abundance
per year. In the frist season (1994195), these peaks were found in the 3rd.