Document Type : Research Paper
Authors
University of Anbar - College of Agriculture
Abstract
This study was conducted at the Biological Control Unit laboratories /College of Agriculture/University of Baghdad , during the period from June 2012 to January 2014. To identify the value of the most important biological indicators of the Local mealybug predator Nephus jaderiensis (Coleoptera : Coccinellidae). The predator is one of the important natural enemies of citrus mealybug Nipaecoccus viridis (Newstead) (Homoptera:Pseudococcidae) which regarded for long time as a key pest of fruit trees especially citrus causing significant economic losses.Study of predation efficiency showed that the consumption of different immature stages of mealybug was highly affected by different temperatures as well as the age of the prey and predator. The total mealybug eggs consumption at temperature (20, 25, 30 and 35)c̊ were 24.9 , 43.9 , 45.9 and 55.6 egg respectively , while 18.9 , 27.9 , 33.7 and 35.4 , 20.8, 30.8 , 35.0 and 41.7 , 6.5 , 10.9 , 15.8 and 18.6 for 1st, 2st and 3st nymphal instars respectively .Consumption by male and female predators were also different being 13.1 , 3.1, 5.5and 2.0 , 17.2 , 5.9 , 7.6 and 2.5 , 17.3 , 6.1 , 6.2 and 2.4 , 17.3 , 5.1 , 6.6 and 3.6 for the fore mentioned immature stages by the adult females , while 15.2 , 6.2 , 7.4 and 3.7 , 19.4 , 4.0 , 7.8 and 5.0 , 18.9 , 5.0 , 6.1 and 2.7 , 19.2 , 4.2 , 7.0 and 3.3 for the male . It was concluded that predator Nephus jaderiensis is one of the good against the Predators as mealybug attack the larvae and adults of different roles of predator mealybug and at good rates, indicating its importance as a factor in the organization of important biological pest population. We recommend conducting further field studies of predator to determine the extent of efficiency in the field, according to local conditions and to determine its role in regulating the population of mealybug and study the compatibility of the predator with other control methods to determine its vital role in integrated pest management programs.
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