nasonovia ribisnigri (mosely) is one of the most important pests of the lettuce plant and it was reported for the first time in ahvaz in 2008. in order to investigate the dominant species of its natural enemies and their population fluctuations, sample were taken arbitrarily from fifty plants twice a week during the growing season in 2010-2012. in this study, ten species of predators, three spe...

abstract in order to investigate density fluctuation and spatial distribution of the main aphidophagous predators and develop a fixed-precision sequential sampling plan, a weekly sweepnet sampling was conducted at five winter wheat fields in gorgan region in northern iran, during two growing seasons of 2006 and 2007. spatial distribution of the predators was described by fitting data to poisson...

Field experiments were conducted in 1989 and 1990 to examine the population fluctuation patterns of Tylenchorhynchus nudus, Criconemella curvata, and Helicotylenchus cornurus in mixed bentgrass and annual bluegrass putting greens on two golf courses near Chicago, Illinois, to determine if fluctuation patterns could be extrapolated to unsampled greens. Fenamiphos-treated and untreated plots were...

Population extinction is of central interest for population dynamics. It may occur from a large rare fluctuation. We find that, in contrast to related large-fluctuation effects like noise-induced interstate switching, quite generally extinction rates in multipopulation systems display fragility, where the height of the effective barrier to be overcome in the fluctuation depends on the system pa...

The global attractivity of the positive steady state is established for a class of nonmonotone time-delayed reaction-diffusion equations subject to the Neumann boundary condition via a fluctuation method. This result is also applied to three population models.

We introduce an effective Lagrangian which describes the classical and semi-classical dynamics of spherically symmetric, self-gravitating objects that may populate the Universe at large and small (Planck) scale. These include worm-holes, black holes and inflationary bubbles. We speculate that such objects represent some possible modes of fluctuation in the primordial spacetime foam out of which...

Population fluctuation monitoring of wheat thrips Haplothrips tritici (Kurdjumov, 1912) (Thysanoptera: Phlaeothripidae) was evaluated on the Tosunbey (wheat) and Tarım92 (barley) cultivars by weekly samplings from plant emergence to harvest season in 2016 2017 Isparta (Center). Adult nymphal stages individuals were collected using direct sampling shake-out methods. In method, cut above-ground p...