Rearing and Release of Aphelinus mali (Hald) (Hymenoptera: Aphelinidae), the Sole Parasitoid of Woolly Apple Eriosoma lanigerum (Hausmann) (Homoptera: Eriosomatidae) on Apple orchards in Ash-Shoubak
Aphelinus mali (Hald) (Hymenoptera: Aphelinidae) is the sole parasitoid of woolly apple aphid (WAA), Eriosoma lanigerum (Hausmann) (Homoptera: Eriosomatidae). Five ratios of parasitoid to aphid colonies were tested to determine the suitable amount of the parasitoid that gives the highest percentage of parasitism under greenhouse conditions. Curve fitting using Table Curve program showed that releasing 6 pairs of unsexed A. mali adults to 100 colonies of WAA results in 98.7 % of parasitism of WAA after 10 days of releasing adults of parasitoids. A valuable suppression of WAA in 2010 was recorded in two apple orchards where the parasitoid was released compared with the orchard in which no release of the parasitoid was done. However, the continuous use of pesticides by apple orchardists in the apple orchards near the experimental orchards resulted in decreasing parasitism rates in 2011 in the apple orchards where release was done due to the movement of WAA from pesticide-controlled orchards to parasitoid-controlled orchards. The government represented by ministry of agriculture is requested to apply a legislation that prevent apple orchardists use insecticides in order to give good opportunity of the parasitoid to build itself.