Scale insects ( Coccoidae : Hemiptera ) infested citrus trees and thier natural enemies , with a key of these pests in Egypt

Scale insects (Coccoidae: Hemiptera) are the most important pests infested citrus trees in Egypt. The present work dealt with the scale insects infested citrus trees and thier natural enemies as well as a key of these pests in Egypt . The results indicated that seven species of scale insects were recorded infested citrus trees in Egypt. Also taxonomic key of the seven species of scale insects was included. During the present work the results indicated that the populations of red scale, Aonidiella aurantii (Maskell) has two peaks one in April and the second one in October. In this work two parasitoids recorded associated with red scale. Theses are Aphytis lingnanensis Compere and Habrolepis aspidioti Compere and Annecke.It is recorded here two peaks for each parasitoid in April and October for A. lingnanensis and in July and November for H. aspidioti in BeniSuef. Also this work indicated that citrus wax scale, Ceroplastes floridensis Comstock has two peaks the first in May and the second in October. In the present work two parasitoids recorded associated with citrus wax scale. These are Metaphycus helvolus (Compere) and Microterus flavus (Howard). It is recorded here two peaks for each parasitoid in May and October for in Gharbiya .The present work observed , black scale Chrysomphalus aonidum (L.) has two peaks the first in May and the second in November. In the present work two parasitoids recorded associted with the black scale. These are Aphytis chrysomphali (Mercet) and Encarsia citrina (Craw). It is recorded here two peaks for each parasitoid in May and November in Qalyubyia. The present work recorded seychellarum mealybug, Icerya seychellarum (Westwood) infested citurs trees in Demmyat and has two annual peaks one in June and the other in November. Also here Rodalia cardinalis Mulsant associated with seychellarum mealybug, I. seychellarum. During the presnt work the results indicated that he purple scale, Lepidosaphes beckii (Newman) has two peaks on citrus trees in Ismaillia . Also one parasitoid, Aphytis lepidosaphes Compere and one predator Chilocorus bipustulatus L. were recorded. During the present work the results indicated that parlatoria black scale, Parlatoria ziziphi (Lucas) has two peaks on citrus trees in Cairo. Two parasitoids, A. lingnanensis and E. citrina were recorded. During the presnt work the results indicated that citrus mealybug, Planococcus citri (Risso) has two peaks on citrus trees in Behira . Two parasitoids, Anagyrus pseudococci (Girault) and Leptomastix dactylopii Howard .


INTRODUCTION
Citrus is the most important fruit in Egypt as far as its acreage, production and exportation potentials are concerned (El-Kassas, 1984).Scale insects are often inconspicuous pests of many evergreen and deciduous plants.They can occur on leaves, twigs, branches or trunks.Their small size and general lack of mobility make them difficult to notice by the casual observer.Scales derive their name from the shell-like, protective covering they form over themselves (Wawrzynski and Ascerno, 2009).Scale insects can weaken plants when they suck their juices, causing leaves to yellow and fall off, resulting in the eventual death of the plant.Honeydew on plants may attract ants as well as sooty mold, which is a black fungus that can result in the death of the plant.Citrus trees are at risk of sustaining damage by scale insect infestations.Scale insects damage citrus trees by extracting vital fluids from the tree, resulting in poor fruit quality and tree health.Hafez et al. (1970a) mentioned that Chrysomphalus aonidum (Linnaeus) ( Hemiptera : Diaspididae) was found to have 4 peaks.Salman (1970) reported that the population of C. aonidum on orange and mandarin, was relatively low from April to August, followed by gradual increase during September and reached its peak during October.The period of big numbers extended to the next January.Aonidiella aurantii (Maskell) has 3-4 generations on citrus trees (Habib et al., 1971).The population peaks of A. aurantii occurred during the period, October, December, January-Febrauray, April-June and August-September (Abul-Nasr et al. 1975).Darwish (1976) found that A. aurantii had 3 annual peaks of abundance.This pest had five overlapping generations per year in Middle Egypt (Hussein, 1976).Abul-Nasr et al. (1977) recorded that the peaks of C. aonidum occurred during October, December, Febrauary-May and May-September. A. aurantii had 3-4 annal generation on citrus in Daqahlyia throughout the two years under investigation (Selim, 1993).Osman, Evon (1996) recorded four overlapping generations for A. aurantii at Beni-Suef governorate.Morsi (1999) studies seasonal abundance of some armored scale insects and the effect of weather factors on these scales in Beni-Suef.He observed A. aurantii and C. aonidum had 3-4 peaks and 3-4 peaks annually, respectively.
The parasitoid, Habrolepis pascuorum Mercet (Hymenoptera : Encyrtidae) played the major role in biological control of C. aonidum (Hafez et al.,1970b).Abdel-Megeed (1977) studied the efficiency of the parasitoids, Aphytis lepidosaphes Compere and Encarsia citrina (Craw) (Hymenoptera: Aphelinidae) in controlling the purpal scale, Lepidosaphes beckii (Newman) (Hemiptera : Diaspididae) on citrus trees at Menofiya.The effect of parasitism was low during summer and winter, while it was high during autumn.It reached its maximum in October and its minimum occurred in February.Karam (1979) recorded two parasitoids from purple scale, L. beckii, namely, A. lepidosaphes and Encarsia sp.Two external parasitoids were reared from the red scale, A. aurantii.These were Aphytis nr.coheni DeBach and A. Hispanicus (Mercet).A hyperparasitoids, Marietta leopardina Motschulsky (Hymenoptera: Aphelinidae) parasitizing, Aphytis spp. was recorded in very few cases.Hafez et al. (1987) studied the abundance of the virous stages of ectoparasite, Aphytis sp. on L. beckii in an orange orchard of Citrus sinensis.Osman (1996) mentioned that the ectoparasitoid, Aphytis lingnanensis Compere had four overlapping activity periods with four peaks in Qalyubiya governorate when associated of A. aurantii).While Aphytis chrysomphali (Mercet) manifested the highest parasitism rate on C. aonidum during autumn season in both years under consideration .Abd-Rabou (1997) studied the parasitoids attacking some species of scale insects.He mentioned that total parasitism of A. aurantii by A. chrysomphali, A. lingnanensis, E. citrina and Encarsia lounsburyi (Berlese & Paoli) reached a maximum during September at South Sinai and Qalyubiya and total parasitism of L. bekii and Parlatoria ziziphi (Lucas) by different aphelinid species reached a maximum during August in Behira and Giza, respectively.Predatory mite Typhlodromus sp. and cocinellid species associated with A. aurantii (Mohamed, 2002).Tawfik et al. (1970) recorded the insect predators associated with the black scale, C. aonidum in Egypt.These predators are Chilocorns bipustulatus L., Scymnus syriacus Muls., Pharoscymnus varius Kirsch., Rodalia cardinalis Muls.and the larvae of Chrysopa carnea Steph., C. bipustulatus L. seem to be the most important predator of this scale infesting citrus orchard.The wax scale, Ceroplastes floridensis Comstock ( Hemiptera : Coccdidae) occurs in a high population from September to January, and then the numbers go down (Hendawy, 1999).The citrus wax scale, C. floridensis on Ficus nitida had three generations (Abd El-Razak, 2000).Hafez et al. (1987) compeaitus Wied. (Abd Allah, 1988).The predators, C. bipustulatus, S. syriacus, Pharaoscymnus varius Kirsch and R. cardinalis were found feeding on some soft scale insects and Chrysop sp.larvae are very common and polyphagous predators feeding on many soft scale insects (Hamed and Hassanein, 1991).C. bipustulatus, S. syriacus, C. carnea, C. septempunctata and O. laevigatus , recorded associated with different species of soft scale insects in Kafr El-Sheikh (El- Agamy et al., 1994).The range of host plants of the monophlebid, Icerya seychellarum (Westwood) includes 44 host plant species (Assem , 1991).Mangoud (2000) found that the margarodid, I. sechellarum has two brood peaks (activity period)/year, on branches in during two seasons.Abd-Rabou (2001a) constructed keys to 26 hymenopterous parasitoid species that attack twenty mealybug species.He mentioned that twenty-five species of mealybugs have no records of parasitoids.The predator R. cardinals recorded associated with Icerya spp.(Hamid and Hassanian, 1991) .
The aim of this work is to study the scale insects infested citrus trees and thier natural enemies as well as a constructed key of these species in Egypt.

MATERIALS AND METHODS
Infested leaves of citrus were examined in the field using a pocket magnification lens.Infested leaves and twigs were collected from different locations in Egypt during 2010 -2011.Identification of scale insects was done by examining adults in Canada Balsam.Also infested leaves and twigs will be examined in the field, using a pocket lens.The leaves and twigs will be collected and placed separately in paper bags for Mona Moustafa 4 further examination in the laboratory.Materials will be kept in a well-ventilated container until the emergence of any natural enemies.Identification of natural enemies will be made by examining mounted adults in Hoyer's medium.Abundance of the populations of scale insects and their natural enemies infested citrus trees were carried out on citrus during 2009-2010 and 2010-2011 in Behira, Beni-Suef, Cairo, Demmyate, Gharbiya, Ismaillia, Qalyubyia.The plant areas selected for these investigations received no chemical control measures for several years.Twenty trees of citrus almost similar in age, size, shape and growth condition were randomly chosen for sampling at a month intervals for each location.On each sampling, 30 leaves and 15 twigs of citrus were chosen at random.Thereafter, the leaves and twigs were kept in a closed paper bags and transferred to the laboratory for further examination and counting.Each leave was stored in a well-ventilated emergence glass tube and monitored daily for parasitoid emergence.Rate of parasitism was determined by dividing the number of emerging parasitoid from each by the number of hosts existing.Predators were counted in filed and transferred to the laboratory for further examination.Simple correlation and regression values were calculated to obtain information about the relationships between the three tested weather factors and the population of the pest and its natural enemies.The constructed key of some parts specially armored scale insects was modified after Miller and Davidson (2005).Data in table (1), showed that the simple correlation between the population of parasitoids Aphytis lingnanensis, Habrolepis aspidioti, maximum, minimum temperatures and % of relative humidity and the mean number of pest were significant or highly significant (r = 0.75, 0.55, 0.90, 0.71 and 0.50), respectively during 2010 .Also, results in Table ( 1), showed that the simple regression for changing the population of parasitoids Aphytis lingnanensis, Habrolepis aspidioti, maximum, minimum temperatures, % of relative humidity and the mean number of pest were significant or highly significant (b = 0.74, 0.51, 0.88, 0.70 and 0.52), respectively during 2010 .2), showed that the simple correlation between the population of parasitoids Aphytis lingnanensis, Habrolepis aspidioti, maximum, minimum temperatures and % of relative humidity and the mean number of pest were significant or highly significant (r = 0.77, 0.54, 0.87, 0.71 and 0.50), respectively during 2011.Also, results in Table (2), showed that the simple regression for changing the population of parasitoids Aphytis lingnanensis, Habrolepis aspidioti, maximum, minimum temperatures and % of relative humidity and the mean number of pest were

Aphytis lingnanensis 2010 Habrolepis aspidioti 2010 Aphytis lingnanensis 2011 Habrolepis aspidioti 2011
Scale insects (Coccoidae: Hemiptera) infested citrus trees and thier natural enemies, Egypt 7 significant or highly significant (b = 0.75, 0.51, 0.86, 0.72 and 0.52), respectively during 2011.During the present work (Figs1&2) the results indicated that the populations of red scale has two peaks one in April and the second one in October.The peaks of this pest recorded by Habib et al. (1971).They stated that A. aurantii has 3-4 generations on citrus trees.Hosny et al. (1972) detretmined the economic threshold at different infestation denisties of A. aurantii on mandarin trees and found that during June and October, more than 0.24, 0.18 females/leaf decreased the yield of mandarin significantly, Abul-Nasr et al. (1975) reported the population peaks of A. aurantii occurred during the period, October, December, January-Febrauray, April-June and August-September, Darwish (1976) found that A. aurantii had 3 annual peaks of abundance, the first occurred during November, the second during May and the third in July, Abd El-Fattah et al. (1978) also stated that the red scale, A. aurantii had 3 annual peaks, in November, May and July , Osman, Evon (1996) recorded four overlapping generations for A. aurantii at Beni-Suef governorate.The first generation occurred from early July to early September.The second occupied the period from early September to early January.While the third one lasted from early January to early April.The fourth generation containued between early April and Mid-June.
In this work two parasitoids recorded associated with red scale.Theses are A. lingnanensis and H. Aspidioti.it is recorded here two peaks for each parasitoid in April and October for A. lingnanensis and in July and November for H. aspidioti in Beni-Suef.While, Osman, Evon (1996) mentioned that the ectoparasitoid, A. lingnanensis had four overlapping activity periods with four peaks in Qalyubiya governorate.The highest rate of parasitism took place in spring in the two years under investigations (25.4 and 28.1%, respectively) who also added that the same parasitoid had four overlapping activity periods with four annual peaks in Beni-Suef.The highest parasitism rate occurred during spring in the two years under investigations (17.5 and 23.5%, respectively on A. aurantii).While A. chrysompahli manifested the highest parasitism rate on C. aonidum during autumn season in both years under consideration (16.3 and 19.5%, respectively).Later Abd-Rabou (1997) studied the parasitoids attacking some species of scale insects.He mentioned that total parasitism of A. aurantii by A. chrysomphali, A. lingnanensis, E. citrina and E. lounsburyi reached a maximum during September with parasitism rates 77 and 80% at South Sinai and Qalyubiya.Morsi (1999) recorded fourteen hymenoptrous parasitoid species of some armored scale insects.He mentioned that the highest percentage of parasitism on A. aurantii ranged between 20-45%.Data in Table (3), showed that the simple correlation between the population of parasitoids Metaphycus helvolus, Microterus flavus, maximum, minimum temperatures , % of relative humidity and the mean number of pest were significant or highly significant (r = 0.65, 0.79, 0.94, 0.66 and 0.67), respectively during 2010 .Also, results in table (3), showed that the simple regression for changing the population of parasitoids, Metaphycus helvolus, Microterus flavus , maximum, minimum temperatures, % of relative humidity and the mean number of pest were significant or highly significant (b = 0.61, 0.78, 0.91, 0.65 and 0.63), respectively during 2010.4), showed that the simple correlation between the population of parasitoids, Metaphycus helvolus, Microterus flavus, maximum, minimum temperatures, %of relative humidity and the mean number of pest were significant or highly significant (r = 0.61, 0.74, 0.90, 0.64 and 0.52), respectively during 2011.Also, results in table (4), showed that the simple regression for changing the population of parasitoid, Metaphycus helvolus, Microterus flavus, maximum, minimum temperatures, % of relative humidity and the mean number of pest were significant or highly significant (b = 0.59, 0.72, 0.89, 0.66 and 0.55), respectively during 2010.The results of the present work indicated that citrus wax scale, C. floridensis has two peaks the first in May and the second in October.These data agree with the findings of Habib et al. (1971).They recorded two annual generations of C. floridensis, on citrus, the first occurred in May-June and the second in September-October.The conducted work recorded this pest in a high infestation in Gharbiya.Swailem et al. (1976) found that population of C. floridensis proved to be considerably higher in Alexandria and Beheira than in Sharqyia and Gharbiya governorates.The population density which causes the damage threshold was around 24.4, 26.6-28.4and 25.1-27 scales per twig in June, October and December, respectively (Salem andZaki, 1985 andHelmy et al. 1986 ). Abd El-Fattah et al., (1991) recorded contradecting data with the present results.They recorded 3 peaks of C. floridensis, mid-April, late-june and eraly November on mandarin.Kamel (2010) reported the occurence of this pest in Qalyubiya on citrus was C. floridensis with the percent of infestaion 0.7 and 1.29 % of the two year under investigation.

Ceroplastes floridensis
In the present work two parasitoids recorded associated with citrus wax scale.These are M.helvolus and M. flavus.It is recorded here two peaks for each parasitoid in May and October for in Gharbiya .While, Hafez et al. (1987)   Data in table ( 5), showed that the simple correlation between the population of parasitoids , A. chrysomphali, E. citrina , maximum, minimum temperatures, % of relative humidity and the mean number of pest were significant or highly significant (r = 0.72, 0.49, 0.79, 0.51 and 0.50), respectively during 2010 .Also, results in table (5), showed that the simple regression for changing the population of parasitoids, A. chrysomphali, E. citrina , maximum, minimum temperatures, % of relative humidity and the mean number of pest were significant or highly significant (b = 0.70, 0.48, 0.75, 0.46 and 0.50), respectively during 2010 .6), showed that the simple correlation between the population of parasitoids, A. chrysomphali, E. citrina, maximum, minimum temperatures, % of relative humidity and the mean number of pest were significant or highly significant (r = 0.74, 0.47, 0.81, 0.55 and 0.50), respectively during 2011.Also, results in table (6), showed that the simple regression for changing the population of parasitoids, A. chrysomphali, E. citrina, maximum, minimum temperatures.% of relative humidity and the mean number of pest were significant or highly significant (b = 0.70, 0.45, 0.79, 0.51 and 0.48), respectively during 2011.Salman (1970) reported that the population of C. aonidum on orange and mandarin, was relatively low from April to August, followed by gradual increase during September and reached its peak during October.The period of big numbers extended to the next January.While, Hafez et al. (1970a) mentioned that C. aonidum was found to have 4 peaks being in March, August, September and November.Also Abul-Nasr et al. (1977) recorded that the peaks of C. aonidum occurred during October, December, Febrauary-May and May-September.The population was largest during late summer in Gharbiya and during winter in Menoufeia, Qalyubiya, Giza and Sharqyia.
In the present work two parasitoids recorded associated with the black scale.These are A. chrysomphali and E. citrina .It is recorded here two peaks for each parasitoid in May and November in Qalyubyia.While Hafez et al. (1970b) relized that the parasitoids played the major role in biological control of C. aonidum.Habrolepis pascuorum proved to be the most important parasitoid of the scale and represented alone about 80% of the total number of emerging parasitoids.Later, Sakr (1994) stated that the parasitoids A. holoxanthus, E. citrina and E. lounsburyi seemed to be more effective on the different developmental stages of C. aonidum during winter and spring, while they were less effective during summer and autumn.

4.Icerya seychellarum (Westwood) (seychellarum mealybug) (Hemiptera: Monophlebidae)
Abundance: The seasonal abundance of the seychellarum mealybug, I. seychellarum was studied for two successive years from 2010 to 2011 on citrus trees in Demmyate.The obtained results in Figs ( 7 & 8) showeded that, the insect population reached maximum during June (78 and 89/ 30 leaves and 15 twigs) in first and second years, respectively.Numbers by R.cardinalis reached maximum (18 and 22/ 30 leaves and 15 twigs) during June of the first and second years, respectively.
Scale insects (Coccoidae: Hemiptera) infested citrus trees and thier natural enemies, Egypt 13 Data in Table ( 7), showed that the simple correlation between the population of R.cardinalis, maximum, minimum temperatures, % of relative humidity and the mean number of pest were significant or highly significant (r = 0.69, 0.91, 0.71 and 0.50), respectively during 2010.Also, results in table ( 7), showed that the simple regression for changing the population of R.cardinalis, maximum, minimum temperatures, % of relative humidity and the mean number of pest were significant or highly significant (b = 0.67, 0.90, 0.70 and 0.51), respectively during 2010 .8), showed that the simple correlation between the population of R.cardinalis, maximum, minimum temperatures, % of relative humidity and the mean number of pest were significant or highly significant (r = 0.67, 0.87, 0.66 and 0.49), respectively during 2011 .Also, results in table (8), showed that the simple regression for changing the population of R. cardinalis maximum, minimum temperatures and % of relative humidity and the mean number of pest were significant or highly significant (b = 0.63, 0.85, 0.65 and 0.47), respectively during 2011.The present work recorded this species infested citurs trees and has two annual peaks one in June and the other in November.Abou El-Khair (1999) reported and studied I. seychellarum on Ficus spp.and Lantania commersoni.Mangoud (2000) found I. sechellarum has two brood peaks (activity period)/year, on branches in during two seasons.The first brood contained two peaks on mid and late-November and the second brood also contained two peaks on first and late-June.On leaves it had two peaks/year on mid-December and late-June.While in the second season, he found two broods/year on branches, the first brood contained two peaks on late-November and mid-December and the brood was noticed in the early-July.On leaves it was found three broods, the first brood contained two peaks on late-October and mid-November, the second brood contained one peak was noticed on mid-December and the third brood contained one peak on early-July.He also studied the distribution of I. seychellarum on apple trees 61.9% of the monophlebid were concentrated on old branches, 31.7% on new branches, 4.2% on old leaves and 2.2% on new leaves (an average of the two seasons, 1994/1995 and 1995/1996).Later Kamel (2010) reported the occurence of this pest in Qalyubiya on citrus was I. Seychelarum with the percent of infestaion 2.09 and 2.16% of the two year under investigation.Hamid and Hassanian (1991) recorded R. cardinals associated with monophlebid, Icerya spp.This work agree with the findinds here.

Lepidosaphes beckii (Newman) ( purple scale) ( Hemiptera : Diaspididae)
Abundance: The seasonal abundance of the purple scale, L. beckii was studied for two successive years from 2010 to 2011 on citrus trees in Ismaillia .The obtained results in Figs (9 & 10) showeded that, the insect population reached maximum during July (185 and 167/ 30 leaves and 15 twigs ) in first and second years, respectively.Numbers by Aphytis lepidosaphes Compere and Chilocorus bipustulatus L. reached maximum (25 and 11/ 30 leaves and 15 twigs ) during July and December of the first year, respectively.While in the second year reached maximum (28 and 8 / 30 leaves and 15 twigs ) during July, respectively.Data in Table ( 9), showed that the simple correlation between the population of Aphytis lepidosaphes, Chilocorus bipustulatus, maximum, minimum temperatures.% of relative humidity and the mean number of pest were significant or highly significant (r = 0.51, 0.48, 0.91, 0.74 and 0.50), respectively during 2010.Also, results in table (9), showed that the simple regression for changing the population of Aphytis lepidosaphes, Chilocorus bipustulatus, maximum, minimum temperatures, % of relative humidity and the mean number of pest were significant or highly significant (b = 0.49, 0.47, 0.94, 0.72 and 0.51), respectively during 2010 .10), showed that the simple correlation between the population of Aphytis lepidosaphes, Chilocorus bipustulatus, maximum, minimum temperatures and % of relative humidity and the mean number of pest were significant or highly significant (r = 0.51, 0.49, 0.92, 0.75 and 0.51), respectively during 2011.Also, results in table (10), showed that the simple regression for changing the population of Aphytis lepidosaphes, Chilocorus bipustulatus, maximum, minimum temperatures, % of relative humidity and the mean number of pest were significant or highly significant (b = 0.48, 0.46, 0.91, 0.69 and 0.50), respectively during 2011.During the presnt work the results indicated that the purple scale, L. beckii has two peaks on citrus trees in Ismaillia .Also one parasitoid, A. lepidosaphes Compere and one predator C. bipustulatus were recorded.Abdel-Megeed (1977) studied the efficiency of the parasitoids, A. lepidosaphes and E. citrina in controlling the purpal scale, L. beckii on citrus trees at Menofiya.The effect of parasitism was low during summer and winter, while it was high during autumn.It reached its maximum in October and its minimum occurred in February.In Alexandria, Karam (1979) studied the armored scale insects and their hymenopterous parasitoids on the grapefruit trees.Who found two parasitoids from purple scale, L. beckii, namely, A. lepidosahes and Encarsia sp.In Kafr El-Sheikh El-Agamy (1981) recorded A. lepidosaphes associated with L. beckii.The abundance of the various stages of ectoparasitoid, Aphytis sp. on L. beckii in an orange orchard of Citrus sinensis.The highest percentage of parasitism was 19.5-30% by immature stages of Aphytis during the winterseason (November-February), with lower levels present during the rest of the year.The rate of adult emergence of Aphytis was in March through August (26.5-58.6%)and lower during the remainder of the year (Hafez et al.,1987).6. Parlatoria ziziphi (Lucas) (parlatoria black scale) ( Hemiptera : Diaspididae) The seasonal abundance of the parlatoria black scale, P. ziziphi was studied for two successive years from 2010 to 2011 on citrus trees in Cairo.The obtained results in Figs (11 & 12) showed that, the insect population reached maximum during April (3250 and 2850/ 30 leaves and 15 twigs) in first and second years, respectively.Numbers by A. lingnanensis e and E, citrina reached maximum (46 and 22/ 30 leaves and 15 twigs) during April and July of the first year, respectively.While in the second year reached maximum (50 and 25/ 30 leaves and 15 twigs) during April and November, respectively.Data in Table (11), showed that the simple correlation between the population of parasitoids A. lingnanensis, E, citrina , maximum, minimum temperature, % of relative humidity and the mean number of pest were significant or highly significant (r = 0.81, 0.45, 0.80, 0.79 and 0.39), respectively during 2010.Also, results in table (11), showed that the simple regression for changing the population of parasitoids A. lingnanensis, E, citrina , maximum, minimum temperature, % of relative humidity and the mean number of pest were significant or highly significant (b = 0.79, 0.43, 0.77, 0.76 and 0.36), respectively during 2010.12), showed that the simple correlation between the population of parasitoids A. lingnanensis, E, citrina, maximum, minimum temperatures and % of relative humidity , the mean number of pest were significant or highly significant (r = 0.85, 0.39, 0.94, 0.71 and 0.70), respectively during 2011 .Also, results in Table ( 12), showed that the simple regression for changing the population of parasitoids A. lingnanensis, E. citrina , maximum, minimum temperatures, % of relative humidity and the mean number of pest were significant or highly significant (b = 0.81, 0.36, 0.91, 0.69 and 0.67), respectively during 2011 .During the present work the results indicated that parlatoria black scale, P. ziziphi has two peaks on citrus trees in Cairo .Also two parasitoids, A. lingnanensis and E, citrina were recorded.Kamel (2010) reported the occurence of this pest in Qalyubiya on citrus with the percent of infestaion 1.3 and 1.7 % of the two year under investigation.Abd-Rabou (1997) mentioned that total parasitism of P. ziziphi by different aphelinid species reached a maximum during August in Giza, respectively.

Planococcus citri (Risso) (citus mealybug) ( Hemiptera : Pseudococcidae)
The seasonal abundance of the citus mealybug, P. citri was studied for two successive years from 2010 to 2011 on citrus trees in Behira.The obtained results in Figs (13 & 14) showed that, the insect population reached maximum during May (1520 and 1021/ 30 leaves and 15 twigs) in first and second years, respectively.Numbers by Anagyrus pseudococci (Girault) and Leptomastix dactylopii Howard reached maximum (18 and 12/ 30 leaves and 15 twigs) during May of the first year, respectively.While in the second year reached maximum (14 and 9/ 30 leaves and 15 twigs) during May, respectively.Data in Table (13), showed that the simple correlation between the population of parasitoids, A. pseudococci, L. dactylopii, maximum, minimum temperatures, % of relative humidity and the mean number of pest were significant or highly significant (r Mona Moustafa 20 = 0.74, 0.51, 0.88, 0.72 and 0.53), respectively during 2010.Also, results in table (13), showed that the simple regression for changing the population of parasitoids, A. pseudococci, L. dactylopii, maximum, minimum temperatures, % of relative humidity and the mean number of pest were significant or highly significant (b = 0.71, 0.52, 0.85, 0.74 and 0.54), respectively during 2010.14), showed that the simple correlation between the population of parasitoids A. pseudococci, L. dactylopii, maximum, minimum temperatures and % of relative humidity and the mean number of pest were significant or highly significant (r = 0.71, 0.51, 0.92, 0.76 and 0.56), respectively during 2011 .Also, results in Table (12), showed that the simple regression for changing the population of parasitoids A. pseudococci, L. dactylopii, maximum, minimum temperatures, % of relative humidity and the mean number of pest were significant or highly significant (b = 0.68, 0.49, 0.90, 0.77 and 0.54), respectively during 2011.During the presnt work the results indicated that citus mealybug, P. citri has two peaks on citrus trees in Cairo.Two parasitoids, A. pseudococci and L. dactylopii was recorded.Abd-Rabou (2001a) recorded 11 parasitoids associated with P. citri.
Comstock (citrus wax scale) ( Hemiptera : Coccdidae) Abundance: The seasonal abundance of the citrus wax scale, C. Floridensis was studied for two successive years from 2010 to 2011 on citrus trees in Gharbiya .The obtained results in Figs (3 & 4) showed that, the insect population reached maximum during June (1360 and 1820/ 30 leaves and 15 twigs) in first and second years, respectively.Numbers by Metaphycus helvolus (Compere) and Microterus flavus (Howard) reached maximum (68 and 74/ 30 leaves and 15 twigs) during June of the first year, respectively.While in the second year reached maximum (35 and 62/ 30 leaves and 15 twigs) during June, respectively.

Table 1 :
Simple correlation and regression values of the population dynamics of Aonidiella aurantii and its parasitoids on citrus trees in Beni-Suef Governorate during 2010 season.
*Data in Table(

Table 2 :
Simple correlation and regression values of the population dynamics of Aonidiella aurantii and its parasitoids on citrus trees in Beni-Suef Governorate during 2011 season.

Table 3 :
Simple correlation and regression values of the population dynamics of Ceroplastes floridensis and its parasitoids on citrus trees in Gharbiya Governorate during 2010 season.
*Data in Table(

Table 4 :
Simple correlation and regression values of the population dynamics of Ceroplastes floridensis and its parasitoids on citrus trees in Gharbiya Governorate during 2011 season.

Table 5 :
Simple correlation and regression values of the population dynamics of , Chrysomphalus aonidum and its parasitoids on citrus trees in Qalyubyia Governorate during 2010 season.

Table 6 :
Simple correlation and regression values of the population dynamics of Chrysomphalus aonidum and its parasitoids on citrus trees in Qalyubyia Governorate during 2011 season.The present work observed, black scale C. aonidum has two peaks the first in May and the second in November.

Table 7 :
Simple correlation and regression values of the population dynamics of Icerya seychellarum and its predator on citrus trees in Demyaata Governorate during 2010 season.

Table 8 :
Simple correlation and regression values of the population dynamics of Icerya seychellarum and its predator on citrus trees in Demyaata Governorate during 2011 season.

Table 9 :
Simple correlation and regression values of the population dynamics of Lepidosaphes beckii and its parasitoid and predator on citrus trees in Ismailia Governorate during 2010 season.

Table ( 10
): Simple correlation and regression values of the population dynamics of Lepidosaphes beckii and its parasitoid and predator on citrus trees in Ismailia Governorate during 2011 season.

Table ( 11
): Simple correlation and regression values of the population dynamics of Parlatoria ziziphi and its parasitoids on citrus trees in Cairo Governorate during 2010 season.
*Data in Table(

Table ( 12
): Simple correlation and regression values of the population dynamics of Parlatoria ziziphi and its parasitoids on citrus trees in Cairo Governorate during 2011 season.

Table 13 :
Simple correlation and regression values of the population dynamics of Planococcus citri and its parasitoids on citrus trees in Behira Governorate during 2010 season.

Table 14 :
Simple correlation and regression values of the population dynamics of Planococcus citri and its parasitoids on citrus trees in Behira Governorate during 2011 season.