Tallgrass prairie (TGP) arthropods are diverse and abundant, yet they remain poorly documented and there is still much to be learned regarding their ecological roles. Fire and grazing interact in complex ways in TGP, resulting in a shifting mosaic of resource quantity and quality for primary consumers. Accordingly, the impacts of arthropod herbivores and detritivores are expected to vary spatially and temporally. Herbivores generally do not control primary production. Rather, groups such as grasshoppers have subtle effects on plant communities, and their most significant impacts are often on forbs, which represent the bulk of plant diversity in TGP. Belowground herbivores and detritivores influence root dynamics and rhizosphere nutrient cycling, and above- and belowground groups interact through plant responses and detrital pathways. Large-bodied taxa, such as cicadas, can also redistribute significant quantities of materials during adult emergences. Predatory arthropods are the least studied in terms of ecological significance, but there is evidence that top-down processes are important in TGP.
The emergence phenology and feeding ecology of annual cicadas in tallgrass prairie are poorly documented. However, these large insects are abundant, and their annual emergence represents a potentially important flux of energy and nutrients from belowground to aboveground. We conducted a study at Konza Prairie Research Natural Area in eastern Kansas to characterize and quantify cicada emergence and associated energy and nutrient fluxes. We established emergence trap transects in three habitat types (upland prairie, lowland prairie, and riparian forest), and collected cicadas every 3 days from May to September. A subset of trapped cicadas was used for species- and sex-specific mass, nutrient, and stable isotope analyses. Five species were trapped during the study, of which three were dominant. Cicadetta calliope and Tibicen aurifera exhibited significantly higher emergence production in upland prairie than in lowland prairie, and were not captured in forested sites at all. T. dorsata emerged from all three habitat types, and though not significant, showed a trend of greater abundance in lowland grasslands. Two less abundant species, T. pruinosa and T. lyricen, emerged exclusively from forested habitats. Nitrogen fluxes associated with total cicada emergence were estimated to be ∼4 kg N ha year in both grassland habitats, and 1.01 kg N ha year in forested sites. Results of stable isotope analyses showed clear patterns of resource partitioning among dominant cicada species emerging from grassland sites. T. aurifera and C. calliope had δC and δN signatures indicative of feeding on shallowly rooted C plants such as the warm-season grasses dominant in tallgrass prairie ecosystems, whereas T. dorsata signatures suggested preferential feeding on more deeply rooted C plants.
Six hydrocarbon components (2-methylhexadecane,n-heptadecane, 2-methylheptadecane, 2-methyloctadecane,n-nonadecane, and 2-methylnonadecane) were identified in sex-pheromone gland extracts and in airborne collections ofHolomelina lamae. Low variability in the ratio of components among individuals indicates tight regulation of blend composition. Minor changes were evident in the quantity and ratio of the blend as a function of time of day. Based on gland extracts, the total quantity of the six components increased from day 1 (X = 6299 ng) to day 4 (X = 7498 ng) and subsequently decreased. No significant correlations were found between total gland contents and wet or dry weights of moths. Emission rates ofH. lamae females were determined from pheromone adsorbed onto Porapak Q. Quantities released peaked shortly after the onset of calling and decreased rapidly as calling continued. Peak release rates ranged from 13 to 350 ng/10 min, and from 37 to 835 ng/60 min. Noncalling females did not emit detectable quantities of pheromone. Based on release rates and the rate of pulsation of the abdominal tip, the average amount released per pulse is not constant. The mean ratio of components released (0.78∶7.45∶ 84.80∶2.84∶2.59∶1.53) was not very different from the ratio of components in gland extracts of 2-day-old females (0.70∶4.19∶90.12∶ 1.65∶1.91∶1.42). We propose that the blend is atomized rather than volatilized from the gland, thus retaining nearly the same ratios in the female's effluvium as in her gland.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.