Evaluating the biocontrol potential of insects auxiliary and bio- insecti-cide extracted from Citrullus colocynthis against Parlatoria blanchardi in date palm in Saoura Oases, Algeria

Abstract

Saoura, is an Algerian desert region, characterized by a height density of date palm trees (more than 300000).Despite this high density, the produc-tion of dates has seen a continuous decrease due to multiple reasons includ-ing increasing water salinity, the spread of many fungal diseases and insect pests where the most serious is Parlatoria blanchardi. The random use of Malathion during the invasions of desert locusts caused an ecological imbal-ance, where the majority of the natural enemies of date palm scale (DPS) disappeared, as consequence the population of DPS expanded increasingly. This study aims to find alternative methods to control pests taking into con-sideration the ecological balance. For this purpose, three entomofauna in-ventories were carried out to study the dynamics of insect populations and for introduction and acclimatization of new auxiliary insects to biocontrol the large infestation of DPS. we also looked to find a biodegradable insecticide extracted from Citrullus colocynthis (desert plant pariah by insects due to its toxicity). By comparing the results we noticed that effectiveness of the colo-cynth aquatic extracts on the target insect was as high as 65.99 % however it’s side effects on ecosystem were negligible unlike Malathion which exter-minated over than 301 non-target insects where 68% are useful such as bees, butterflies, some entomophagous insects and even some vertebrate such as Oenanthe leucopyga. Finally, a phytochemical screening and toxico-logical studies are recommended to determine exactly which component in colocynth is more effective on DPS and its undesirable effect on human health.