Comparative development and demographic parameters of Euphyllura pakistanica on four olive cultivars

The development, reproduction and growth population parameters of the olive psyllid, Euphyllura pakistanica Loginova (Rhynchota Psyllidae) were determined on four olive cultivars, Fishomi, Oil, Yellow and Shenge, under controlled laboratory conditions at 20 +/- 1 degrees C, 60 +/- 5% RH and a photoperiod of 16:8 (L:D). There were significant differences in the egg and pre-oviposition period and female longevity on the four olive cultivars. The life span was longest on Yellow (51.71 +/- 1.01 days) among the four cultivars. The survival rates (lx.) in newly emerged adults were 72.89, 72.85, 63.72 and 51.81% on Shenge, Fishomi, Yellow and Oil cultivars, respectively. The gross and net fecundity rates were significantly higher on Yellow cultivar (397.94 +/- 18.42 and 234.87 +/- 8.80 eggs/lifetime). The net reproduction rate (R-0) was significantly affected by different olive cultivar being highest on Yellow (82.84 +/- 3.98) and lowest on Oil (42.01 +/- 1.43). The highest and lowest intrinsic rates of increase (r(m)) were observed on Yellow (0.167 +/- 0.001) and Oil (0.144 +/- 0.001) cultivars, respectively. Our findings showed that the development and demographic parameters of olive psyllid E. pakistanica were influenced by different cultivars. This implies that morphological and biochemical mechanisms may be involved in the defence strategies of olive trees against this olive psyllid.