Poorjavad, N., J. Khajehali, B. Hatami and A. Motamedi. 2014. Study on biological characteristics seasonal population fluctuations of elm aphid, Tinocalli nevskyi (Hem., Aphididae), in Shahrekord. Iranian Journal of Plant Protection Science

Elm aphids damage elm trees through feeding and producing considerable amounts of honeydew especially on trees of recreational areas. Biological characteristics and seasonal fluctuations of the aphid were studied in two sites by weekly sampling from infested trees during 2002-2003. To determine important life table parameters of the aphid, Tinocallis nevskyi Remaudiere, Quednau and Heie, in natural conditions leaf cages were used. The results indicated that the aphid overwinter as egg on the branches of trees. First nymphs and alatae were observed in early and late April, respectively. The population of viviparae was increased rapidly in late April and May and went down in summer. Wingless oviparae and alate males appeared in mid fall. Oviposition occurred in early November to early December. Intrinsic rate of increase (r_m), finite capacity for increase ( l), net reproductive rate (R₀) and mean generation time of the aphid were 0.15±0.02 day^-1, 1.17±0.04 day^-1, 14.89±1.54 nymphs and 17.54±0.30 days, respectively.