Evaluation of biological control of hoary cress (Lepidium draba L.) by applying gall mite (Aceria drabae (Nal.) (Acari: Eriophyidae) in Shirvan region

In order to find an approach for controlling hoary cress using gall mite (Aceria draba (Nal.) (Acari: Eriophyidae), various studies were conducted in three regions of Shirvan, northern Khorasan Province (Iran) during spring 2011. Preliminary studies that included collecting, identifying and screening bio-control agents for hoary cress were carried out. For this purpose, 40 plants (20 infected and 20 healthy) were transplanted to the pots. After establishment, the control plants were sprayed with an acaricide and others infested with the gall mite at three stages. At the end of the growing season, plant height, stem diameter, shoot fresh weight, shoot dry weight and seed number of the hoary cress were measured, accordingly. The host-range results showed that the mite did not feed from any of the plants except for hoary cress. The effect of gall mite on the vegetative and reproductive characteristics of hoary cress was significant (p≤0.01) and could reduce the seed number of hoary cress by 98% compared with the control. This mite was able to reduce the vegetative and reproductive organs and seed number of hoary cress.