A two-year life table study of Glyphodes pyloalis Walker (Lep.: Pyralidae) under field conditions

Lesser mulberry pyralid, Glyphodes pyloalis Walker is a serious monophagous pest of mulberry in northern Iran. In this study, life table parameters of G. pyloalis were determined during 2014 and 2015 under field conditions in Rasht, Guilan, Iran. Data were analyzed based on an age-stage, two-sex life table. The results showed that total immature developmental time was significantly different for two generations in 2014, whereas, there was no significant difference among three generations of G. pyloalis in 2015 under field conditions. In addition, total preoviposion period, oviposition period and fecundity of adults in first generation were significantly higher than second generation in 2014. The intrinsic rate of increase (r) of G. pyloalis in first generation (0.093 day-1) was significantly less than the second generation in 2014. Whereas, the net reproductive rate (R0), gross reproductive rate (GRR) and the mean generation time (T) were significantly higher in first generation than second generation in 2014. Furthermore, the r, R0 and T values ranged from 0.081 – 0.093 day-1, 14.66 – 24.62 offspring and 32.91 – 33.32 days among three generations in 2015. Because of different life table parameters of the pest generations under field conditions, the results of present study confirmed that collection of life table data under field conditions is invaluable for understanding the seasonal population dynamics of G. pyloalis to construct an effective pest management program.