Survey of scale insects and their natural enemies in Riyadh Region (Saudi Arabia) حصر للحشرات القشرية وأعدائها الطبيعية في منطقة الرياض (المملكة العربية السعودية)

Abstract

أجريت عملية حصر عام للحشرات القشرية التي تصيب أشجار الفاكهة وأشجار الظل ونباتات الزينة في منطقة الرياض وما يصاحبها من أعداء حيوية خلال العام 1987 1988 م وقد جمعت العينات من مدينة الرياض والقرى المحيطة بها وقد شملت الدرعية، العينة، حريملاء، القويعية، ضرماء، المزاحمية، سنام وقد أمكن الحصول على 10 أنواع من الحشرات القشرية وكانت الحشرة القشرية هي السائدة كما أمكن حصر 11 نوعا من الأعداء الطبيعية للحشرات القشرية منها ثمانية أنواع (7طفيليات، مفترس واحد) يسجل وجودها لأول مرة في المملكة

A general survey of scale insects attacking fruit trees shade trees and ornamental plants in Riyadh region was carried out thourghout the year 19871988 Specimens were collected from the city of Riyadh as well as from the following surrounding village Deriya Uyayna Huraymila Quwayiya Durma Muzahimiya and Sanam Ten species of scales were recovered Aonidiella orientalis (Newstead) on a wide range of host plants ; Parlatoria blanchardii (Targ) and Asterolecanium phoenicis Rao on Phoenix dactylifera Parlatoria crypta McKenzie on Nerium oleander ; Coccus longulus (Douglas) and C hesperidium Linn on Tipuana tipa ; Saissetia oleae (Oliv) on Ficus nitida ; Parasaissetia nigra (Nietner) on F carica ; Contigaspis zillae (Hall) on F nitida and Crotolaria aculeata and Lecanodiaspis africana Newstead on F carica and Acacia curenbergiana The former species was the most dominant It seems to be more adapted to the arid climate of the area Previous surveys carried out in different regions of Saudi Arabia has been reviewed by AbuThuraya [1] who mentioned 31 species of scales belonging to 4 families and 19 genera MatileFerrero [2 pp 219228] added several speciesto the previous list 20 of which were recorded for the first time in Saudi Arabia In the present work 11 species of natural enemies emerged from infested scales ; 7 parasitoids for A orientalis 3 for L africana and a single predator for P blanchardii Eight of these (marked by an asterisk) were recorded for the first time in Saudi Arabia The parasitoids of A orientalis included 4 aphelinids ; Marietta leopardina Mots Encarsia aurantii (Howard) E sp or citrina (Craw) Azotus chrysomphali Ghesq and 3 encyrtids ; Comperiella lemniscata Corn and Ann C aspidiotophaga Subba Rao and Haprolepis aspidiotii Corn and Ann Two encyrtids Lakshaphagus hautfeuilli (Mahd) and Parechthrodrynus combretae RiSb and a single pteromalid Scutellista sp or hispanica (Masi) were recorded as parasitoids of L africana The nitidulid Cybocephalus sp was the only predator recorded for P blanchardii This predator is probably capable of attacking other seales species Three species of parasitoids belonging to the genera Aphytis Haprolepis and Aspidiotophaga were reared from the oriental scale insect A orientalis received in California with a shipment from Saudi Arabia [3] Nine species of parasitoids of scale insects in Saudi Arabia have been mentioned by AbuThuraya [1] Two aphelinids in the genera Azotus and Marietta and two encyrtids in the genus Comperiella were recorded by Moussa [4] as parasitoids for A orientalis in Riyadh region The authors are grateful to the staff of the British Museum (Natural History) London for kindly identifying the specimens