02866nas a2200229   4500008004100000245010900041210006900150300001100219490000700230520206600237653001402303653004302317653002302360653003902383653002402422653002202446653003102468100001602499700001902515700001902534856008302553       2015                        eng d00aWeather affects grasshopper population dynamics in continental grassland over annual and decadal periods0 aWeather affects grasshopper population dynamics in continental g  a29 -390 v683 a<p>Understanding the complex dynamics of insect herbivores requires consideration of both exogenous and endogenous factors at multiple temporal scales. This problem is difficult due to differences in population responses among closely related taxa. Increased understanding of dynamic relationships between exogenous and endogenous factors will facilitate forecasting and suggest nodes in the life cycle of economically important species susceptible to intervention by managers. This study uses an information-theoretic approach to examine the contributions of weather and density to model population densities and growth rates of nine common grasshopper species from continental U.S. grassland over 25 years. In general, grass-feeding species and total grass-feeders as a functional group were most closely associated with weather during the year before hatching. Increased variability in prior growing season precipitation was associated with increased densities of Mermiria bivittata, Opeia obscura, Phoetaliotes nebrascensis, and the grass-feeding guild. Melanoplus sanguinipes densities tended to be smaller following warm fall seasons, while Amphitoruns coloradus declined during the positive phase of the North Atlantic Oscillation or after warmer than average winters. Population growth rate dynamics of all grouped species combinations were best explained by models including variability in precipitation during the prior year growing season. Large-scale Pacific Decadal Oscillation (PDO) patterns were also associated with growth rate dynamics of the mixed-feeding species group. Density showed a negative relationship with population growth rates of five species. This study indicates the importance of parental and diapause environmental conditions and the utility of incorporating long-term, readily obtained decadal weather indices for forecasting grasshopper densities and identifying critical years with regard to grasshopper management&mdash;at least to the degree that the past will continue to predict the future as global climates change.</p>10aacrididae10aatmospheric oscillations (NAO PDO SOI)10adensity dependence10aexogenous and endogenous feedbacks10agrasshopper control10ainsect herbivores10apopulation growth rate (R)1 aJonas, J.L.1 aWolesensky, W.1 aJoern, Anthony  uhttps://www.sciencedirect.com/science/article/pii/S1550742414000128?via%3Dihub01403nas a2200193   4500008004100000245009300041210006900134300001100203490000600214520074700220653001900967653001700986653001601003653001401019100001601033700001901049700001901068856012201087       2007                        eng d00aInsect development under predation risk, variable temperature, and variable food quality0 aInsect development under predation risk variable temperature and  a47 -650 v43 aWe model the development of an individual insect, a grasshopper, through its nymphal period as a function of a trade-off between prey vigilance and nutrient intake in a changing environment. Both temperature and food quality may be variable. We scale up to the population level using natural mortality and a predation risk that is mass, vigilance, and temperature dependent. Simulations reveal the sensitivity of both survivorship and development time to risk and nutrient intake, including food quality and temperature variations. The model quantifies the crucial role of temperature in trophic interactions and development, which is an important issue in assessing the effects of global climate change on complex environmental interactions.10aeco-physiology10agrasshoppers10aTemperature10avigilance1 aLogan, J.D.1 aWolesensky, W.1 aJoern, Anthony  uhttp://knz.lternet.edu/content/insect-development-under-predation-risk-variable-temperature-and-variable-food-quality02110nas a2200205   4500008004100000245007200041210006900113300001300182490000800195520145400203653001701657653002001674653001401694653002701708653001601735100001601751700001901767700001901786856009901805       2006                        eng d00aTemperature- dependent phenology and predation in arthropod systems0 aTemperature dependent phenology and predation in arthropod syste  a471 -4820 v1963 aA central issue in ecology is to determine how environmental variations associated with global climate change, especially changing temperatures, affect trophic interactions in various ecosystems. This paper develops a temperature-dependent, stage-based, discrete, cohort model of the population dynamics of an insect pest under pressure from a predator. Guided by experimental data, the model is applied specifically to predation of grasshoppers by rangeland lycosid spiders. The development rate of insect arthropods is strongly affected by temperature, and these temperature-dependent phenological effects couple with shifts in the daily activity periods for both prey and predator, thereby increasing or decreasing opportunities for interaction. The model addresses these effects quantitatively by introducing a temperature-dependent, joint-activity factor that enters the predator’s functional response. The model also includes a prey mortality rate that is temperature-dependent through the prey development rate. The model is parameterized using field and experimental data for spiders and grasshoppers. We investigate the effect of the solar power index (sunlight), mean temperature, and temperature variation, as measured by amplitude, on the developmental times and survivorship both with, and without, predation. We conclude that increasing variation in temperature results in a stronger relative effect on survivorship due to predation.10agrasshoppers10aLycosid spiders10aphenology10aPredator–prey models10aTemperature1 aLogan, J.D.1 aWolesensky, W.1 aJoern, Anthony  uhttp://knz.lternet.edu/content/temperature-dependent-phenology-and-predation-arthropod-systems