01824nas a2200229 4500008004100000245009200041210006900133300001100202490000800213520112800221653001401349653001701363653002401380653001601404653002601420653002401446653001501470653001201485100001601497700001901513856006201532 2013 eng d00aDietary selection and nutritional regulation in a common mixed-feeding insect herbivore0 aDietary selection and nutritional regulation in a common mixedfe a20 -260 v1483 a

The geometric framework provides a way for understanding the multi-dimensional nutritional relationships between consumers and their food. We use this approach to further our understanding of the feeding and nutritional ecology of a ubiquitous mixed-feeding insect herbivore that consumes a variety of host plants spanning a wide range of nutritional composition. Our overall objective was to examine feeding decisions, resulting performance, and post-ingestive consequences in a common mixed-feeding insect herbivore, Melanoplus bivittatus (Say) (Orthoptera: Acrididae), when presented with paired diets differing in protein:carbohydrate (p:c) ratio. Intake p:c of M. bivittatus differed among all but two treatments and in many cases was farther than expected from the previously identified p:c intake target for this species. Despite this variability in intake of protein and carbohydrate, we found few effects of the diet treatments on performance or post-ingestive processing. However, our results suggest that when feeding on high-quality diets, nutrients consumed in excess may be stored rather than excreted.

10aacrididae10acarbohydrate10ageometric framework10ahomeostasis10aMelanoplus bivittatus10anutritional ecology10aOrthoptera10aprotein1 aJonas, J.L.1 aJoern, Anthony uhttps://onlinelibrary.wiley.com/doi/abs/10.1111/eea.1206502565nas a2200205 4500008004100000245011800041210006900159300001300228490000800241520171600249653001401965653001201979653003301991653003702024653001502061653001702076100001302093700001902106856023402125 2012 eng d00aVariable effects of dipteran parasitoids and management treatment on grasshopper fecundity in a tallgrass prairie0 aVariable effects of dipteran parasitoids and management treatmen a123 -1300 v1023 a

Grasshoppers host a number of parasitoids, but little is known about their impact on grasshopper life history attributes or how those impacts may vary with land use. Here, we report on a three-year survey of nine grasshopper species in a tallgrass prairie managed with fire and bison grazing treatments. We measured parasitoid prevalence and the impact of parasitoid infection on grasshopper fecundity to determine if grasshopper-parasitoid interactions varied with management treatment. Adult female grasshoppers were collected every three weeks from eight watersheds managed with different prescribed burning and grazing treatments. Grasshopper fecundity with and without parasitoids was estimated through dissections of reproductive tracts. Dipteran parasitoids from two families (Nemestrinidae and Tachinidae) were observed infecting grasshoppers. We found significant effects of grazing treatment, but not burn interval, on grasshopper-parasitoid interactions. Parasitoids were three times more abundant in watersheds with bison grazing than in ungrazed watersheds, and the relative abundance of nemestrinid and tachinid flies varied with grazing treatment. Parasitoid prevalence varied among grasshopper species from <0.01% infected (Mermiria bivittata) to 17% infected (Hypochlora alba). Parasitoid infection reduced individual grasshopper fecundity, with stronger effects on current reproduction than on past reproduction. Furthermore, current fecundity in parasitized grasshoppers was lower in grazed watersheds compared to ungrazed watersheds. Nemestrinid parasitoids generally had stronger impacts on grasshopper fecundity than tachinid parasitoids, the effects of which were more variable.

10agrassland10aGrazing10ahost-parasitoid interactions10aKonza Prairie Biological Station10aOrthoptera10areproduction1 aLaws, A.1 aJoern, Anthony uhttps://www.cambridge.org/core/journals/bulletin-of-entomological-research/article/variable-effects-of-dipteran-parasitoids-and-management-treatment-on-grasshopper-fecundity-in-a-tallgrass-prairie/EB1AD93DB7D975E1009489797D88DF2E02323nas a2200193 4500008004100000245007900041210006900120300001300189490000700202520169800209653003701907653001701944653001501961653001501976653001701991100001302008700001902021856008902040 2011 eng d00aGrasshopper fecundity responses to grazing and fire in a tallgrass prairie0 aGrasshopper fecundity responses to grazing and fire in a tallgra a979 -9880 v403 a

Grasshopper abundance and diversity vary with management practices such as fire and grazing. Understanding how grasshopper life history traits such as fecundity respond to management practices is key to predicting grasshopper population dynamics in heterogeneous environments. Landscape-level experimental fire and bison grazing treatments at the Konza Prairie Biological Station (Manhattan, KS) provide an opportunity to examine how management affects grasshopper fecundity. Here we report on grasshopper fecundity for nine common species at Konza Prairie. From 2007 to 2009, adult female grasshoppers were collected every 3 wk from eight watersheds that varied in fire and grazing treatments. Fecundity was measured by examining female reproductive tracts, which contain a record of past and current reproductive activity. Body size was a poor predictor of fecundity for all species. Despite large differences in vegetation structure and composition with management regime (grazing and fire interval), we observed little effect of management on grasshopper fecundity. Habitat characteristics (grasshopper density, vegetation biomass, and vegetation quality; measured in 2008 and 2009) were better predictors of past fecundity than current fecundity, with species-specific responses. Fecundity increased throughout the summer, indicating that grasshoppers were able to acquire sufficient nutritional resources for egg production in the early fall when vegetation quality is generally low. Because fecundity did not vary across management treatments, population stage structure may be more important for determining population level reproduction than management regime at Konza Prairie.

10aKonza Prairie Biological Station10alife-history10amanagement10aOrthoptera10areproduction1 aLaws, A.1 aJoern, Anthony uhttps://academic.oup.com/ee/article-abstract/40/5/979/412531?redirectedFrom=fulltext01992nas a2200181 4500008004100000245011200041210006900153300001500222490000700237520132500244653001801569653001801587653001501605653002401620653002301644100001901667856012401686 2004 eng d00aVariability in grasshopper densities in response to fire frequency and bison grazing from tallgrass prairie0 aVariability in grasshopper densities in response to fire frequen a1617 -16250 v333 aWhile weather can contribute significantly to grasshopper population dynamics in North American grasslands, local environmental conditions resulting from land use practices may be equally important. In this study, significant differences in grasshopper density were detected among adjacent watersheds from Kansas Flint Hills tallgrass prairie that differed in fire frequency and especially bison grazing treatments. Grasshopper densities were ≈2.5 times greater in grazed watersheds compared with ungrazed ones. Grasshopper densities also varied somewhat in response to fire frequency, mostly in species-specific ways. No treatment interactions on overall grasshopper density were detected. The effects of fire frequency and bison grazing were implemented in part through their combined effect on the structural heterogeneity of vegetation, and other habitat characteristics. Individual grasshopper species responded uniquely to combinations of fire frequency and bison grazing. Grazing resulted in significant increases in density for seven of the nine most abundant species; fire frequency affected two species; and one species did not respond to either fire or grazing. Understanding effects of habitat on grasshopper densities provides opportunities to manage these populations for economic or conservation needs.10aBison grazing10aKonza Prairie10aOrthoptera10apopulation dynamics10aprescribed burning1 aJoern, Anthony uhttp://lter.konza.ksu.edu/content/variability-grasshopper-densities-response-fire-frequency-and-bison-grazing-tallgrass02599nas a2200193 4500008004100000245010000041210006900141300001500210490000700225520191900232653002602151653001502177653002202192653001502214100001402229700001702243700001902260856012602279 2002 eng d00aAboveground invertebrate responses to land management differences in a central Kansas grassland0 aAboveground invertebrate responses to land management difference a1142 -11520 v313 aMacroinvertebrate communities in a central Kansas grassland were examined to assess their responses to differences in land management and explore their viability for biological assessment of grasslands. Canopy (drop-trap) and ground-dwelling (pitfall traps) communities were quantitatively sampled from June-September 1998 and 1999. The responses of the whole arthropod community and two focal groups, Coleopteran families and Orthopteran species, to three land use types (brome fields, old fields, and native prairies) were examined. Vegetation analyses reflected clear differences among land use types. Bromus inermis Leyss, an exotic grass, and Andropogon gerardii Vitman, a native grass, dominated brome fields and native prairie sites, respectively. Old fields were composed of a mixture of native and exotic plant species. Coleopteran family richness and diversity were significantly greater in native prairies than brome fields (P < 0.05), whereas orthopteran species richness and diversity peaked in brome fields. Diversity and richness of all arthropod groups examined were significantly, positively correlated with plant species diversity and richness in drop-trap samples (P < 0.05). Coleopteran family diversity and richness in pitfall samples were positively correlated with abundance of native plants, but orthopteran species diversity and richness were negatively correlated with native plant abundance. Coleopteran and orthopteran responses to land use appeared linked to differences in management practices. Whereas coleopterans appeared most influenced by plant community composition, orthopterans showed sensitivity to mechanical disturbance associated with haying on native prairie. Plant and arthropod group diversities were not consistently correlated, demonstrating that arthropod groups can reflect differences in a landscape that may not be apparent from examining plant communities alone.10abiological assessment10aColeoptera10aindicator species10aOrthoptera1 aJonas, J.1 aWhiles, M.R.1 aCharlton, R.E. uhttp://lter.konza.ksu.edu/content/aboveground-invertebrate-responses-land-management-differences-central-kansas-grassland