Demographic parameters of the pink stem borer, Sesamia cretica Lederer (Lepidoptera: Noctuidae) were estimated on its two main host plants, maize and sugarcane. The present study was conducted under laboratory conditions at 27±1 ̊C, 50±10% Relative Humidity (RH %), and a photoperiod of 0:24 (L:D) hour for the larval stage and 16:8 (L:D) hour for the other life stages. The raw data were analyzed ...

The bifurcation that occurs from the extinction equilibrium in a basic discrete time, nonlinear juvenile-adult model for semelparous populations, as the inherent net reproductive number R0 increases through 1, exhibits a dynamic dichotomy with two alternatives: an equilibrium with overlapping generations and a synchronous 2-cycle with non-overlapping generations. Which of the two alternatives i...

The development, survival, and fecundity of Scymnus subvillosus (Goeze) (Coleoptera: Coccinellidae) were studied at 20, 25, 30, and 35 degrees C, 60 +/- 5% RH, and a photoperiod of 16:8 (L:D) h (5,000 lux) under laboratory conditions. The total developmental time from egg hatch to adult eclosion ranged from 22.6 d at 20 degrees C to 10.6 d at 35 degrees C. The developmental rates of the egg sta...

Bio-insecticidal effects of seven Chinese medicinal herbs on mortality, fecundity, developmental periods and life table parameters of the grape phylloxera were investigated. In an excised root bioassay experiment aqueous extracts from seven Chinese medicinal herbs increased grape phylloxera first instar mortality (26.00-38.50%) compared to other instars. The intrinsic rate of increase (rm), fin...

The beet armyworm, Spodoptera exigua, is one of the most important pests of sugar beet in Iran. The aim of this study was to determine the effect of water and nitrogen treatments of sugar beet planton developmental time and fecundity life table parameters of the pest. An experiment was carried out under laboratory conditions (25±2oC, 70±5% R.H. and 12L: 12D) on larvae reared...

an investigation was carried out to study the developmental time, reproduction and life table of three populations of the onion thrips, thrips tabaci lindeman, on onion (khorasan and golestan populations) and also on tobacco (mazandaran population) in the laboratory at 25â°c, 50% rh and 16: 8 h l: d. the total life cycle from egg to adult of khorasan, golestan and mazandaran populations were ga...

development, reproduction and life table parameters of tetranychus urticae koch were determined on leaves of peach (g. h. hale cultivar) at different temperatures, ranging from 13 to 33°c under laboratory conditions. no development was observed at 13°c. egg-to-adult developmental time decreased gradually from 17 to 27°c and increased at higher temperatures (27 to 33°c). an average of 136.43 deg...

The Russian wheat aphid (RWA), Diuraphis noxia (Kurdjumov), is one of the main pests small-grain cereal crops, including bread wheat, Triticum aestivum (Poaceae). In a series glasshouse experiments, we evaluated systemic effect endophytic Beauveria bassiana strain PPRI 7598 on D. biotype RWASA1 using three South African cultivars, Gariep, Molopo, and Kariega. objectives study were: (a) to deter...

the effects of plant densities (25, 35 and 45 plants m-2 as d1, d2 and d3 respectively), and inoculation with rhizobium bacteria (without rhizobium, with rhizobium and rhizobium + microelement application), on growth and yield were studied in chickpea (cicer arietinum l.). experiment was carried out in 2008 at research farm of the faculty of agriculture of university of mohaghegh ardabil, a fac...

The notion of a potential-growth indicator came to being in the field matrix population models long ago, almost simultaneously with pioneering Leslie model for age-structured dynamics, although term has been given and theory developed only recent years. represents an explicit function, R(L), L elements indicates position spectral radius relative 1 on real axis, thus signifying growth, or declin...