Parasitoids and predators associated with scale insects and mealybugs ( Hemiptera : Coccoidea ) on fruit trees at coastal area in Egyptian western desert

In the present investigation, many insect parasitoids and predators were recorded associated with scale insects and mealybugs (Hemiptera: Coccoidea) on the eleven species of deciduous and evergreen fruit trees in six localities at the Western North Coast of Egypt during December 2007February 2010. Eighteen parasitoid species of superfamily Chalcidoidaea belonging to five families and ten genera were collected. Eleven species of insect predators were found to be associated with scale insects and mealybugs which attacking fruit tree species during the period of study. These species belonging to four orders, Coleoptera, Hemiptera, Mantodea and Neuroptera.


INTRODUCTION
Integrated pest management (IPM) aims to control pest populations with the least disruption of the environment.Emphasis is given to the fruit utilization of the regulating and limiting factors, such as natural enemies, existing in the ecosystem.A higher level of environmental quality is assured through the limitations set on the use of pesticides in order to maximize the role of natural enemies.Scale insects especially armored scales are considered among the pests most amenable to biological control because of their sedentary habits, colonial distribution and relative population stability.Parasitoids and predators are likely to be relatively more successful on this type of host or prey population (Erler and Tunc, 2001).
Therefore, it is very important to reestablish and renew a considerable background about the occurring natural enemies (parasitoids and predators) associated with scale insects and mealybugs infested both deciduous and evergreen fruit trees at North Western coast of Egypt under dry and irrigation system.

MATERIALS AND METHODS
In order to survey scale insects and mealybugs associating with some deciduous and evergreen fruit trees as well as their natural enemies (parasitoids and predators) in the western north coast of Egypt, several locations were chosen.These locations represent different types of irrigation as follows: Inspection were started from December, 2007 till February, 2010 in the different locations under investigation except El-Hammam since the survey in this location started from January, 2009 till December 2009 on fig, olive and pear trees.After leaves and branches had been examined and the sample insects were counted, the specimens were confined in glass jars and kept in the laboratory for securing any emerging parasitoids.For classifying the inspected species of scale insects, slide preparations of adult females were made and examined microscopically at a power of 10-15 X and identified as well as their natural enemies (parasitoids and predators) by Scale Insects and Mealybugs Division, Plant Protection Institute, Agricultural Research Center, Egypt and by the key of parasitoids by Goulet et al. (1991) and Hayat (1970).

RESULTS AND DISCUSSION
Eighteen species of super family Chalcidoidea belonging to five families and ten genera were collected during the period of study (December, 2007 till November, 2009) associated with armored and soft scales.The obtained results in Table (1) shows the parasitoid species, its coccid hosts, host plants, localities and date of inspection.These parasitoid species can be listed as follows: I. Family: Aphelenidae 1-Aphytis sp.
This parasitoid was observed parasitizing the fig scale, Lepidosaphes conchiformis (Gmelin) (Hemiptera: Diaspididae) associated with fig trees at Burg el-Arab area in rain-fed farm during February (Table 1)

2-Aphytis aonidiae (Mercet)
It is a major parasitoid of San Jose Scale (SJS), Quadraspidiotus perniciosus (Comstock) in Southern California (Gulmahamad & DeBach, 1978).This Parasitoid is produced parthenogenetically and the males were rare and a single female was able to kill 62 first instar scale, 75.3 of 2nd instar nymphs or 37. showed that A. coheni a parasitoid of Leucaspis riccae Targioni-Tozzetti was found on olive trees at Burg el-Arab under rain-fed system during January-May, June, September and November.

4-Aphytis lepidosaphes Compere
The mussel scale parasitoid, A. lepidosaphes is an ectoparasitoid of A. aurantii, Chrysomphalus aonidum (Linnaeus), Cornuaspis beckii Newman, Insulaspis gloverii (Packard), Lepidosaphes sp.This species also play as a hyperparasite on some Hymenopterous parasitoids (Universal Chalcidoidea Database, 2010).Abd-Rabou (1999) recorded A. lepidosaphes on C.beckii in Egypt. A. lepidosaphes was recorded parasitizing L.conchiformis on fig trees at Burg el-Arab during March-April and November-December, while in the farm under irrigation at el-Hammam, it was observed during March -May.It is important to mention here that, this species was found in samples of L. conchiformis on fig at Libya during October.A. lepidosaphes was also found parasitizing H. lataniae which infest olives at Burg el-Arab during February-March and parasitizing Q. perniciosus on pear under irrigation at El-Hammam during October (Table 1).

7-Habrolepis aspidiotii Compere & Annecke
Abd-Rabou (1999) recorded H. aspidiotii on H. lataniae and Parlatoria ziziphi in Egypt.On olive trees at Burg el-Arab under dry system, H. aspidiotii was recorded parasitized on H. lataniae during Januray & November -December and A. nerii during July (Table,1).The data obtained also showed that it parasitized on H. rapax and Q. perniciosus infesting apple trees under irrigation at Burg el-Arab during October and July, respectively.On pear trees at El-Hammam area Q. perniciosus was parasitized by H. aspidiotii during November (Table 1).

11-Mytaphycus sp.
The species of the encyrtid genus Metaphycus are primary parasitoid of scale insects belonging to families Coccidae, Eriococcidae and Asterolecaniidae (Benzeya and Hayat, 1993).This Encyrtid parasitoid was recorded parasitized on fig pit scale, Russelaspis pustulans pustulans (Hemiptera: Asterolecanidae) on fig under irrigation at El-Hammam area during the period of February to March and August (Table1).

12-Metaphycus flavus (Howard)
M. flavus is a facultative gregarious parasitoid of different soft scales.Benzeya and Hayat (1993) mentioned that its host in India is Pulvinaria maxima Green (Hemiptera: Coccidae) and it distribute in Palaearctic; Nearctic; Neotropical and Australian zones.M. flavus was recorded parasitized on S. coffeae infesting olive trees in rain-fed farm at Burg El-Arab area during July (Table 1).

13-Metaphycus lounsburyi (Howard)
This species was recorded on S. oleae associated with olive trees at Burg El-Arab under dry system during May-June.

14-Diversinervus elegans (Silvestri)
Table (1) showed that D. elegans is a parasitoid of C. longulus associated with guava trees under irrigation system at Merghem during May.

16-Tetrastichus ceroplastae (Girault)
It is know as white wax parasitoid.It is a primary one on C. rusci associated with fig trees at Merghem and coastal ridge during April and July, respectively (Table 1 This species of genus Signophora Ashmead were recorded parasitized on H. lataniae associated with guava trees during February and December at Burg el-Arab; on fig trees during February and on olive during March in the same location.At El-Hammam area, Signiphora sp was recorded H. latania associated with fig and olive trees during February and November, respectively .The data also showed that it parasitized on H. rapax infesting apple trees under irrigation at Burg el-Arab during November (Table 1).

The predators
Eleven species of insect predators were found to be associated with scale insects and mealybugs which attacking the concerned fruit trees during the period of study.These species are belonging to four orders.Order Coleoptera represented by eight coccinellid species and each of Order Hemiptera, Order Mantodea and Order Neuroptera represented by one species.
Table (2) showed that the scientific name of these species, host plant, site and recorded date of each species.The predator species can be listed as follows: species was observed during May on Guava trees at Burg El-Arab under irrigation system (Table 2).

3-Aphytis coheni De Bach
1 mated females by sucking their body fluid.According to Universal Chalcidoidea Database (2010), A. aonidiae distributes in many regions of the world as Argentina, Armenia, Chile, Cyprus, Egypt, Europe, Greece, Hungary, Iran, Italy, Romenia, Spain, Turkey, UK, USA and USSR.During the present study, A. aonidiae was collected from Hemiberlesia lataniae (Signoret) infesting olive trees at Burg el-Arab during February and November and from El-Hammam during November.It parasitized the fig scale, L. conehifermis in Burg el-Arab and El-Hammam during March and March-April, respectively (Table1).The data also showed that A. aonidiae parasitized SJS, Q. perniciosus on pear trees during November in the farm under irrigation at Burg el-Arab and El-Hammam.

Table 1 :
Chalcidoid parasitoids recorded with scale insects infesting fruit tree species at Western Northern Coast of Egypt during December, 2007 to November, 2009.

Family Encyrtidae 9-Anagyrus sp.
(1)d-Rabou, 2003)of the genus Anagyrus (Howard) is the most successfully used in Biological control and survey conducted during 2000/2001 in different localities in Egypt revealed this genus on 7 species of mealybugs(Abd-Rabou, 2003).The data tabulated in Table(1)shows that Anagyrus sp. was parasitized on P. citri infesting guava trees at Burg el-Arab during April.

Family: Pteromalidae 17-Scutellista caerulea Fonscolombe
). IV.This species was recorded parasitizing on three soft scales, S. oleae on fig trees at Burg el-Arab during May to August, S. coffeae at Burg el-Arab on olive during June-September, November and December, while on fig trees was recorded during July-October at Burg el-Arab too, in El-Hammam area during July-August.S. caerulea was recorded parasitizing on C. rusci on fig trees during May and on guava during November at Burg el-Arab (Table 1).It is important to mention here that S. caerulea was observed also parasitized on C. rusci associated with fig trees at Libya during May.El-Minshawy et al. (1978) found that S. cyanea was prevalent on S. coffeae and S. oleae from August to November and on C. floridensis in March and September in Egypt.V.

Table 2 :
The Predators recorded with scale insects and mealybugs infesting fruit trees species at Western Northern Coast of Egypt during December, 2007 to November, 2009.Cydonia vicina var.nilotica (Mulsant) The data in Table (2) shows that C. vicina var nilotica was collected from guava trees under irrigation system at Burg El-Arab during June.El-Serafi et al. (2004) recorded C. vicina isis on guava trees in Egypt.

-Order Hemiptera 9-Reduvius sp.
showed that this predator was collected during June at Coastal ridge from fig trees and olive trees, while at Burg El-Arab it was observed during May on fig trees.5-Hyperaspissp.The larvae of Hyperaspis sp. was observed during this study associated with A. nerii on olive trees at Burg El-Arab during March and July (Table 2).6-Rodaliacardinalis(Mulsant)L.This species was found to be distributed in Australia, Cyprus, France, Italy, Japan, Malta, Portugal and US (Zipcode Zoo 2006).El-Serafi et al. (2004) recorded R. cardinalis on guava trees in Egypt.The data in Table(2)showed that this species was observed on I. seychellarum seychellarum infesting guava trees at Burg El-Arab during May, June, December and in Merghem during June, while on pear trees under irrigation system it was observed at Burg El-Arab during November.7-Scymnussp.This predator was observed on olive trees at Burg El-Arab during February, March, April, June, July and in El-Hammam during July, while on fig trees it observed at El-Hammam during October.(Table2).Scymnus subvillosus (Goeze) S. subvillosus is common in the olive grove of the Mediterranean region and both adult and larvae are predaceous stages (Ba M'hamed and Chemseddine, 2002).According Zipcode Zoo (2006), this predator distributes in many regions of the world as Afghanistan, Austria, Cyprus, France, Germany, Greece, Hungary, Italy, Malta, Portugal, Romania, Spain and Turkey.S. subvillosus was collected from fig trees in Coastal ridge during June, at El-Hammam during May and at Burg El-Arab during the period of May-November (Table2).IITable(2)shows that Reduvius sp.(belonging to Family Reduviidae) was associated with olive trees under irrigation system at El-Hammam during June.III

-Order Neuroptera 10-Chrysopa sp.
During this study Chrysopa sp.(belonging to Family Chrysopidae) was observed in Burg El-Arab on olive trees during October and June, on plum trees and pear trees during July, while at El-Hammam it was associated with olive trees during June and at coastal ridge on fig trees it was recorded during July (Table,2).IV

-Order Mantoidea 11-Sphodromantis bioculata (Burmeister)
This species which is belonging to Family Mantidae was recorded on fig trees at El-Hammam during August (Table 2).