Evaluation of The effect of diatomaceous earth and Two compounds derived from chinaberry tree (Melia Azedarach) extract on mortality of nymphs and spawning rate of common pistachio psyllid Agonoscena pistaciae Burkhardt & Lauterer (Hem.: Psyllidae) under field conditions

Common pistachio psyllid Agonoscena pistaciae Burkhardt & Lauterer (Hem.: Psyllidae) is one of the main pests of pistachio trees in Iran. Given the risks of excessive use of chemical pesticides, it seems that one of the methods to minimize pesticide pollution is to use plant and mineral compounds.

In this research, the mineral composition of diatomaceous earth and the formulated compounds of chinaberry tree (Melia Azedarach) plant extract (A: chinaberry extract + soap and B: chinaberry extract + potassium silicate) were used to investigate the mortality of nymphs and spawning rate.

Investigating the results indicated that the leaves treated with chinaberry extract + soap with a concentration of 3000 mg/liter following 5 and 10 days and the combination of chinaberry extract + soap (3000 mg/liter) and diatomaceous earth (10000 mg) g/liter) following 5 days were reported to have the highest mortality of nymphs and the lowest spawning rate compared to the control group. Moreover, the results have indicated that the spawning rate of the leaves treated with the combination of chinaberry extract + potassium silicate and the combination of chinaberry extract + soap and diatomaceous earth after 15 days is not significantly different compared to that of the control.

Given the favorable effect of the chinaberry + soap and the combination of chinaberry extract + soap and diatomaceous earth in reducing the number of nymphs and the spawning rate, it seems that spraying pistachio trees with these compounds can properly control the psyllid population.