the life table parameters of schizaphis graminum (rondani) (hemiptera: aphididae) on four commercial cultivars of wheat (kohdasht, pastor, tajan and zagros) were determined in laboratory conditions. fertility life table were constructed using age-specific survivorship (lx) and age-specific fecundity (mx) and subsequently analyzed using jackknife method and anova. there were significant differen...

Spatial distribution or how abundances vary through space is an important trait of insect populations. Knowledge of the spatial distribution provides a basis for understanding various aspects of population biology including resource exploitation, intraspecific competition or the dynamics of predators and parasitoids. For insect pests, information on the spatial structure of populations may help...

The invasion of ecological systems by nonindigenous species is now recognized as a growing global problem that imposes significant economic and ecological damages. In the United States alone, the total costs of nonindigenous species have been estimated to be at least $137 billion per year (Pimentel et al.). Approximately one-fourth of the value of the country’s agricultural output is lost to no...

common wheat, triticum aestivum l. is of the greatest importance among the few crop plants that are grown extensively and for food in iran. among the reported wheat's pests, greenbug schizaphis graminum (rondani) causes severe damage to the crop. because of the adaptation of the aphid to different wheat varieties being varied, this study was designed to focus on the effect of some common w...