No abstract

Experiments were conducted to estimate the susceptibility of two apple cultivars (Anna and Golden dorset) to infestation with Panonychus ulmi Koch (Acari: Tetranychidae) and its population fluctuation during the two successive seasons, 2012 and 2013 at Menoufia governorate. The results showed that, Anna cultivar was the most highly susceptible recording average of 7.34 and 10.5 mite moving stages/leaf during the two successive seasons, respectively. The lower infestation was recorded with Golden dorset cultivar, being 1.6 & 7.49 mite moving stages/leaf during the two successive seasons, respectively. Susceptibility of apple cultivars to infestation with P. ulmi may be affected by plant leaf morphological structure and its chemical contents. The density of trichomes of Golden dorset cultivar was higher than that of Anna cultivar, the less density of trichomes the more mite infestation. Also, when the level of total phenolic compounds increased the infestation percentage decreased, while no effect of Tannins occurred. Mite populations reached its peak during May and April in the first and second seasons, respectively, and infestation was lower in the first season.

fficacy of three acaricides (Ortus 5% EC, Milbeknock 1% EC and Cascade 10% DC) and predatory insect; Chrysoperla carnea Stephens was evaluated on the European red mite Panonychus ulmi Koch (Acari: Tetranychidae) movable stages infested apple orchards during the two successive seasons; 2012 and 2013 at Darawa village, Ashmon, Menoufia governorate, as well as determining the biochemical changes in the treated insects. The results show that, The highest reduction percentages of P. ulmi movable stages during 2012 and 2013 seasons were recorded with Ortus followed by Milbecknok then the predatory insect; C. carnea, while the lowest reduction percentages were recorded with Cascade. The effect of the two acaricides Ortus and Milbecknok (the highest toxic acaricides) on the major biochemical components of P. ulmi adult females showed that, the acaricide Ortus achieved high effects on the total lipids content and the two enzymes Acetylcholinesterase (AchE) and Glutathione-S-transferase (GST). The acaricide Milbecknok recorded high effects on the total lipids and carbohydrates contents and lipase, trehalase, amylase, AchE and GST enzymes. The two acaricides Ortus and Milbecknok are effective in controlling European red mite on apple trees and this can be attributed to abnormal changes of the major biochemical components in the treated mites. The predatory insect; C. carnea has efficient predation against P. ulmi and resulting increasing in the reduction of mite populations.