Population Fluctuations and Spatial Distribution of Galls Induced by Tetraneura ulmi (Hem.: Pemphigidae) in Miandoab, West Azerbaijan

Abstract Population density and spatial distribution pattern of Tetraneura ulmi (L.) (Hemiptera: Pemphigidae) galls on elm, Ulmus densa Litv. were determinedin Miandoab, West Azerbaijan during 2015-2016. 20 samples from every four cardinal directions in lower one third part of crown were randomly selected from each tree per sampling dates. One leaf was selected as a sampling unit. One data set including 200 leaves collected from 10 trees. Results showed that population density of aphid galls in the south of tree, was significantly higher than other directions. The spatial distribution pattern of aphid galls using Taylor's method, index of dispersion and Lloyd's mean crowding was regular. Moreover, there was no significant relationship using linear regression between the temperature and relative humidity with the number of galls. Correlation between length and width of galls with number of aphids was calculated. There was significant positive correlation between number of aphids and the length / width of galls.