Hymenptrous parasitoids as a bioagents for controlling maybugs ( Hemiptera : Pseudococcidae ) in Egypt

A wide range of parasitoids are found attacking the mealybug species belonging to families namely Aphelinidae, Encyrtidae, Platygastridae, and Signiphoridae. A list of 26 species of parasitoids were recorded attacking the different species of mealybug; 20 species belong to family Encyrtidae, and one species from Platygastridae are primary parasitoids. The rest of parasitoids (5 species) are secondary parasitoids which belong to the families; Aphelinidae,Encyrtidae, Pteromalidae, Signiphoridae and iInformation about host insects, host plants, distribution, biological notes and role in the biological control for mealybug’ parasitoids were recorded in this paper.


INTRODUCTION
Mealybugs are small soft-bodied insects with sucking mouthparts belonging to order Hemiptera.A list of 55 species of mealybugs were recorded in Egypt until 2008 belong to Margarodidae and Pseudococcidae ( 6, 49 species in respective).The mealybug species, Planococcus ficus, Planococcus citri, Ferrisia virgatus, Maconellicoccus hirsutus , Saccharicoccus sacchari, Icerya aegyptiaca and Icerya purchase are considered as serious pests of many economic important plant and ornamental plant in Egypt.The population of mealybugs on Citrus, Mango, Guava, Apple and Pears are under control by its associated natural enemies but on Grape vine, vitis vinifera which is considered one of the most important crops in Egypt is infested by the pseudococcid, Planococcus ficus causing damage by feeding activity of its nymphs and adults, on clusters.Moreover, during its feeding on different parts of the plant and excreting honey dew that supports the growth of sooty mould.Sooty and sticky bunches harboring mealybug individuals and their white cottony wax masses tend to be inferior in the marketing value as table grapes.In addition to this obvious damage, P. ficus is capable of transmitting grape vine leafroll disease from plant to another.
The problem with P. ficus in grapevine is already very grave and ways to diminish the losses caused by this mealybug should be searched for and the only sustainable way on along-term basis in biological control.A wide range of encyrtid parasitoids in the world are found attacking the vine mealybug; i.e., Anagyrus pseudococci, Leptomastix flavus, Clausenia josefi, Ccoccidoxenoides pergrinues and Leptomastidae abnormis.These parasitoids are located on the Egyptian fauna.Rearing and releasing these parasitoids will produce the hope to impact this pest.

RESULTS
Table 1, represents a list of parasitoids attacking mealybugs in Egypt.Role in the biological control: A. kamali was reared from: M. hirsutus, with an average parasitism rates of 20.7% and the maximum parasitism rates was 37% (Abd-Rabou, 2000b).
Remarks: This species was recorded for first time in Egypt by Priesner and Hosny (1940).
Role in the biological control: A. pseudococci was reared from N. viridis with an average parasitism rates of 9.4% and the maximum parasitism rates was 35.4% Abd-Rabou and Abd El-Gawad (2002).This parasitoid was reared from S. sacchari with an average parasitism rates of 1.8 % and the maximum parasitism rates was 12% (Abd-Rabou, 2000a  (1997).
Biological notes: This parasitoid is a solitary endoparasitoid on F. virgata .The second nymphal instar of the host is the most preferred one for parasitism; Ferrisia adults are never attacked.The means of total developmental period for the parasitoid was 37.9 days.Most of the progeny (96.4%) was females, while 3.6% were males (Awadallah et. al 1999).Role in the biological control: The parasitoid was collected from August 1 st and showed two peaks of abundance; on September 1 st and on October 15 th and vanished completely from the collected samples from February 1 st to July 15 th.Rates of parasitism was ranged between 1.4% and 16.4% on the host plant Acalypha macrophylla and ranged between 16.7 % to 70.6 % on the host plant Lantana camara (Attia, 1997).

Table 1 :
List of parasitoids attacking mealybugs in Egypt:According to Table (1) each parasitoid will be discussed taking into consideration host insect, host plant, distribution, remark notes, biological notes and its role in the biological control in concern.