برآورد خسارت کنه گالی در جنگل‌های بلوط (Quercus brantii) در اطراف شهرستان خرم‌آباد از استان لرستان

The forests of Zagros, which are mainly covered by oak trees, make up about 40% of Iran's forested area, spanning approximately six million hectares. In recent decades, these forests, including those around Khorramabad city, have faced various threats such as changes in land use, deforestation, grazing of livestock, fires, climate change, and invation of pests and diseases. One significant factor contributing to the damage in these forests is the presence of pests and diseases; one such pest is the gall mite Aceria querci (Garman, 1883). This species belongs to the superfamily Eriophyoidae, order Trombidiformes, and suborder Prostigmata. The mites in this superfamily are minuscule and typically specialize in specific hosts, often targeting a single species or species within the same plant genus. In these forests, this species of pest causes felt galls on Q. branthii oak leaves. In the surfaces of the leaf, it creates ridges about 2 to 3 mm in height and a corresponding depression in the lower part, in a rusty brown color. Usually, there are many spots on the leaves of this oak species. To estimate the damage caused by this pest in the oak forests of Khorramabad city, five stations, each with an area of one hectare, were selected as indicators of vegetation cover and damaging factors. The selection was done using random complete block design (C.R.D). The damage caused by this pest was estimated in the stations at specific sampling times. The damage estimation method included direct and approximate observation. Comparing the average percentage of gall mite damage in the investigated stations showed that the percentage of damage varied in these areas. The highest percent of damage was observed in the North Mele Shabanan station with an average of 18±02.29, and the lowest rate of damage was in the Nozhian station with an average of 2±0.33percent. The places were classified into three statistical groups based on the percentage of damage. It was found that the effect of the area on the percentage of gall mite damage was completely significant (P<.01). This could be caused by weather conditions, including differences in temperature and humidity, as well as different genetics of trees or gall mites, or a combination of these factors.