Adam Wallner - Academia.edu (original) (raw)
Papers by Adam Wallner
a b s t r a c t Auchenorrhyncha (i.e., leafhoppers, treehoppers, spittlebugs, and planthoppers) r... more a b s t r a c t Auchenorrhyncha (i.e., leafhoppers, treehoppers, spittlebugs, and planthoppers) represent some of the most diverse groups of herbivorous insects in the tallgrass prairie biome, they have close associations with many native prairie grasses and forbs, and respond in predictable ways to changes in native grassland degradation. These attributes make Auchenorrhyncha ideal candidates in the development of a habitat quality index to measure tallgrass prairie quality. In this study we propose the development of a species-based habitat quality index called the Auchenorrhyncha quality index or AQI as a useful method in tracking the condition of tallgrass prairie quality. The AQI is computed by summing six ecological characteristics (i.e., host plant specificity, voltinism, overwintering microhabitat, wing length, habitat fidelity, and origin) for each Auchenorrhynchan insect encountered, yielding coefficient of conservatism (CC) values that range from 0 (habitat generalist/tolerant to disturbance) to 18 (habitat specific/intolerant to disturbance). These CC values are averaged and combined with species richness producing un-weighted by abundance AQI (AQI w/outN ) and weighted by abundance AQI (AQI w/N ). The performance of the AQI was evaluated by examining the effects of sampling intensity on this index using a sweep net and a vacuum apparatus from 10 sites located on the three main North American tallgrass prairie communities, wetmesic, sand, and loess hill. Scientists and land managers can adequately sample Auchenorrhyncha from four transects using a vacuum. Also, the highest AQI values were found from loess hill and sand prairies, indicating that conservation efforts should focus on these prairie communities. Additional applications of the AQI may include: (1) discriminating prairie quality at various spatial scales; (2) testing hypotheses about the effects of disturbance on prairie habitat (e.g. prescribed burning); (3) using the AQI as a model in developing habitat quality indices based on other diverse groups of grassland insects; and (4) the AQI has the capacity to be readily modified in assessing the quality of other biomes. Ultimately, the AQI should be used in combination with other habitat quality indices based on other diverse groups of organisms, such as plants and other insects, to provide a more complete assessment of native habitat quality.
Journal of Insect Conservation, 2012
Prescribed burning has been important in maintaining the structure of plant communities in the ta... more Prescribed burning has been important in maintaining the structure of plant communities in the tallgrass prairie. However, implementation of these burn regimes often overlooks responses of other taxa, particularly arthropods. In this study, the timing and frequency of burns were examined on one of the most diverse and abundant groups of herbivorous insects, Auchenorrhyncha. These insects are ideal candidates in understanding the effects of fire on prairie arthropods because they are among the most numerous invertebrate herbivores in the prairie and they have ecological characteristics that confer a wide range of responses to prescribed burning. A total of 19 Illinois hill prairies were sampled along the Mississippi and Sangamon Rivers in the summer of 2006 using a modified leaf-blower vacuum. These sites exhibited a wide range of burn management, from unburned to recently burned, and having been burned multiple times. Species richness, Auchenorrhyncha Quality Index (with and without abundance data) and the mean coefficient of conservatism (with and without abundance data) were calculated for each site. Results suggest that unburned sites supported the greatest number of species and had higher Auchenorrhyncha Quality Index and mean coefficient of conservatism values than sites undergoing burn management. In order for land managers to maintain the prairie Auchenorrhyncha community and conserve vascular plants, this study recommends infrequent rotational burning with a minimum of 3-5 years; although additional studies are needed to determine the appropriate number of years between each burn.
Ecological Indicators, 2013
a b s t r a c t Auchenorrhyncha (i.e., leafhoppers, treehoppers, spittlebugs, and planthoppers) r... more a b s t r a c t Auchenorrhyncha (i.e., leafhoppers, treehoppers, spittlebugs, and planthoppers) represent some of the most diverse groups of herbivorous insects in the tallgrass prairie biome, they have close associations with many native prairie grasses and forbs, and respond in predictable ways to changes in native grassland degradation. These attributes make Auchenorrhyncha ideal candidates in the development of a habitat quality index to measure tallgrass prairie quality. In this study we propose the development of a species-based habitat quality index called the Auchenorrhyncha quality index or AQI as a useful method in tracking the condition of tallgrass prairie quality. The AQI is computed by summing six ecological characteristics (i.e., host plant specificity, voltinism, overwintering microhabitat, wing length, habitat fidelity, and origin) for each Auchenorrhynchan insect encountered, yielding coefficient of conservatism (CC) values that range from 0 (habitat generalist/tolerant to disturbance) to 18 (habitat specific/intolerant to disturbance). These CC values are averaged and combined with species richness producing un-weighted by abundance AQI (AQI w/outN ) and weighted by abundance AQI (AQI w/N ). The performance of the AQI was evaluated by examining the effects of sampling intensity on this index using a sweep net and a vacuum apparatus from 10 sites located on the three main North American tallgrass prairie communities, wetmesic, sand, and loess hill. Scientists and land managers can adequately sample Auchenorrhyncha from four transects using a vacuum. Also, the highest AQI values were found from loess hill and sand prairies, indicating that conservation efforts should focus on these prairie communities. Additional applications of the AQI may include: (1) discriminating prairie quality at various spatial scales; (2) testing hypotheses about the effects of disturbance on prairie habitat (e.g. prescribed burning); (3) using the AQI as a model in developing habitat quality indices based on other diverse groups of grassland insects; and (4) the AQI has the capacity to be readily modified in assessing the quality of other biomes. Ultimately, the AQI should be used in combination with other habitat quality indices based on other diverse groups of organisms, such as plants and other insects, to provide a more complete assessment of native habitat quality.
Biodiversity and Conservation, 2013
ABSTRACT In this study a habitat quality index based on Auchenorrhyncha (Insecta: Hemiptera) spec... more ABSTRACT In this study a habitat quality index based on Auchenorrhyncha (Insecta: Hemiptera) species composition was used to investigate the index’s ability in discriminating hill prairie quality along a gradient of disturbance, based on the Illinois Natural Areas Inventory grading criteria; whether this index differs from other vegetation-based measures of quality; and examine the relationships between Auchenorrhyncha and vegetation integrity and diversity. Auchenorrhyncha and vascular plants were sampled from 14 Illinois glacial-drift hill prairies representing a range in quality. Insects and plants were sampled from late July through August, 2007 and analyzed using univariate and multivariate analyses. Results from this study showed that Floristic Quality Index, Auchenorrhyncha Quality Index, as well as other Auchenorrhyncha and plant diversity and integrity index values are greater in high, followed by mid, then low quality hill prairie remnants. Also, these analyses showed that perennial C4 grasses are strongly associated with prairie Auchenorrhyncha. These data suggest that judicious used of prescribed burning or brush removal may be needed to prevent woody-encroachment from eliminating prairie vegetation and Auchenorrhyncha on low quality sites; and restoration of perennial C4 grasses on low quality sites are needed to support more prairie Auchenorrhyncha fauna. Reintroductions of conservative (i.e., prairie-dependent and fire-sensitive) Auchenorrhyncha may also be needed to improve Auchenorrhyncha integrity on mid and low quality sites but these reintroductions need to be used in combination with reduced burn management or the inclusion of unburned refugia to reduce the extirpation of these fire-sensitive insects.
The immatures stages of 8 of the 11 genera (Amastris Stål, Bajulata Ball, Erosne Stål, Harmonides... more The immatures stages of 8 of the 11 genera (Amastris Stål, Bajulata Ball, Erosne Stål, Harmonides Kirkaldy, Idioderma Van Duzee, Neotynelia Creão-Duarte & Sakakibara, Tynelia Stål, and Vanduzea Goding) of the tribe Amastrini are described for the first time along with brief diagnoses of Membracidae and the subfamily Smiliinae. A key to genera and notes on biology are provided. Multiple species of most genera are illustrated. Based on its distinct nymphal morphology, Vanduzea laeta nolina Ball is elevated to specific rank as Vanduzea nolina stat. n., and Bajulata, despite the superficial similarity of its adults to those of Vanduzea, is confirmed as warranting generic rank based on its unique nymphal morphology. Colombia is a new country record for Tynelia.
The brown marmorated stink bug, Halyomorpha halys, a native of Asia, has become a serious invasiv... more The brown marmorated stink bug, Halyomorpha halys, a native of Asia, has become a serious invasive pest in the USA. H. halys was first detected in the USA in the mid 1990s, dispersing to over 41 other states. Since 1998, H. halys has spread throughout New Jersey, becoming an important pest of agriculture, and a major nuisance in urban developments. In this study, we used spatial analysis, geostatistics, and Bayesian linear regression to investigate the invasion dynamics and colonization processes of this pest in New Jersey. We present the results of monitoring H. halys from 51 to 71 black light traps that were placed on farms throughout New Jersey from 2004 to 2011 and examined relationships between total yearly densities of H. halys and square hectares of 48 landscape/land use variables derived from urban, wetland, forest, and agriculture metadata, as well as distances to nearest highways. From these analyses we propose the following hypotheses: (1) H. halys density is strongly associated with urban developments and railroads during its initial establishment and dispersal from 2004 to 2006; (2) H. halys overwintering in multiple habitats and feeding on a variety of plants may have reduced the Allee effect, thus facilitating movement into the southernmost regions of the state by railroads from 2005 to 2008; (3) density of H. halys contracted in 2009 possibly from invading wetlands or sampling artifact; (4) subsequent invasion of H. halys from the northwest to the south in 2010 may conform to a stratified-dispersal model marked by rapid long-distance movement, from railroads and wetland rights-of-way; and (5) high densities of H. halys may be associated with agriculture in southern New Jersey in 2011. These landscape features associated with the invasion of H. halys in New Jersey may predict its potential rate of invasion across the USA and worldwide.
a b s t r a c t Auchenorrhyncha (i.e., leafhoppers, treehoppers, spittlebugs, and planthoppers) r... more a b s t r a c t Auchenorrhyncha (i.e., leafhoppers, treehoppers, spittlebugs, and planthoppers) represent some of the most diverse groups of herbivorous insects in the tallgrass prairie biome, they have close associations with many native prairie grasses and forbs, and respond in predictable ways to changes in native grassland degradation. These attributes make Auchenorrhyncha ideal candidates in the development of a habitat quality index to measure tallgrass prairie quality. In this study we propose the development of a species-based habitat quality index called the Auchenorrhyncha quality index or AQI as a useful method in tracking the condition of tallgrass prairie quality. The AQI is computed by summing six ecological characteristics (i.e., host plant specificity, voltinism, overwintering microhabitat, wing length, habitat fidelity, and origin) for each Auchenorrhynchan insect encountered, yielding coefficient of conservatism (CC) values that range from 0 (habitat generalist/tolerant to disturbance) to 18 (habitat specific/intolerant to disturbance). These CC values are averaged and combined with species richness producing un-weighted by abundance AQI (AQI w/outN ) and weighted by abundance AQI (AQI w/N ). The performance of the AQI was evaluated by examining the effects of sampling intensity on this index using a sweep net and a vacuum apparatus from 10 sites located on the three main North American tallgrass prairie communities, wetmesic, sand, and loess hill. Scientists and land managers can adequately sample Auchenorrhyncha from four transects using a vacuum. Also, the highest AQI values were found from loess hill and sand prairies, indicating that conservation efforts should focus on these prairie communities. Additional applications of the AQI may include: (1) discriminating prairie quality at various spatial scales; (2) testing hypotheses about the effects of disturbance on prairie habitat (e.g. prescribed burning); (3) using the AQI as a model in developing habitat quality indices based on other diverse groups of grassland insects; and (4) the AQI has the capacity to be readily modified in assessing the quality of other biomes. Ultimately, the AQI should be used in combination with other habitat quality indices based on other diverse groups of organisms, such as plants and other insects, to provide a more complete assessment of native habitat quality.
Journal of Insect Conservation, 2012
Prescribed burning has been important in maintaining the structure of plant communities in the ta... more Prescribed burning has been important in maintaining the structure of plant communities in the tallgrass prairie. However, implementation of these burn regimes often overlooks responses of other taxa, particularly arthropods. In this study, the timing and frequency of burns were examined on one of the most diverse and abundant groups of herbivorous insects, Auchenorrhyncha. These insects are ideal candidates in understanding the effects of fire on prairie arthropods because they are among the most numerous invertebrate herbivores in the prairie and they have ecological characteristics that confer a wide range of responses to prescribed burning. A total of 19 Illinois hill prairies were sampled along the Mississippi and Sangamon Rivers in the summer of 2006 using a modified leaf-blower vacuum. These sites exhibited a wide range of burn management, from unburned to recently burned, and having been burned multiple times. Species richness, Auchenorrhyncha Quality Index (with and without abundance data) and the mean coefficient of conservatism (with and without abundance data) were calculated for each site. Results suggest that unburned sites supported the greatest number of species and had higher Auchenorrhyncha Quality Index and mean coefficient of conservatism values than sites undergoing burn management. In order for land managers to maintain the prairie Auchenorrhyncha community and conserve vascular plants, this study recommends infrequent rotational burning with a minimum of 3-5 years; although additional studies are needed to determine the appropriate number of years between each burn.
Ecological Indicators, 2013
a b s t r a c t Auchenorrhyncha (i.e., leafhoppers, treehoppers, spittlebugs, and planthoppers) r... more a b s t r a c t Auchenorrhyncha (i.e., leafhoppers, treehoppers, spittlebugs, and planthoppers) represent some of the most diverse groups of herbivorous insects in the tallgrass prairie biome, they have close associations with many native prairie grasses and forbs, and respond in predictable ways to changes in native grassland degradation. These attributes make Auchenorrhyncha ideal candidates in the development of a habitat quality index to measure tallgrass prairie quality. In this study we propose the development of a species-based habitat quality index called the Auchenorrhyncha quality index or AQI as a useful method in tracking the condition of tallgrass prairie quality. The AQI is computed by summing six ecological characteristics (i.e., host plant specificity, voltinism, overwintering microhabitat, wing length, habitat fidelity, and origin) for each Auchenorrhynchan insect encountered, yielding coefficient of conservatism (CC) values that range from 0 (habitat generalist/tolerant to disturbance) to 18 (habitat specific/intolerant to disturbance). These CC values are averaged and combined with species richness producing un-weighted by abundance AQI (AQI w/outN ) and weighted by abundance AQI (AQI w/N ). The performance of the AQI was evaluated by examining the effects of sampling intensity on this index using a sweep net and a vacuum apparatus from 10 sites located on the three main North American tallgrass prairie communities, wetmesic, sand, and loess hill. Scientists and land managers can adequately sample Auchenorrhyncha from four transects using a vacuum. Also, the highest AQI values were found from loess hill and sand prairies, indicating that conservation efforts should focus on these prairie communities. Additional applications of the AQI may include: (1) discriminating prairie quality at various spatial scales; (2) testing hypotheses about the effects of disturbance on prairie habitat (e.g. prescribed burning); (3) using the AQI as a model in developing habitat quality indices based on other diverse groups of grassland insects; and (4) the AQI has the capacity to be readily modified in assessing the quality of other biomes. Ultimately, the AQI should be used in combination with other habitat quality indices based on other diverse groups of organisms, such as plants and other insects, to provide a more complete assessment of native habitat quality.
Biodiversity and Conservation, 2013
ABSTRACT In this study a habitat quality index based on Auchenorrhyncha (Insecta: Hemiptera) spec... more ABSTRACT In this study a habitat quality index based on Auchenorrhyncha (Insecta: Hemiptera) species composition was used to investigate the index’s ability in discriminating hill prairie quality along a gradient of disturbance, based on the Illinois Natural Areas Inventory grading criteria; whether this index differs from other vegetation-based measures of quality; and examine the relationships between Auchenorrhyncha and vegetation integrity and diversity. Auchenorrhyncha and vascular plants were sampled from 14 Illinois glacial-drift hill prairies representing a range in quality. Insects and plants were sampled from late July through August, 2007 and analyzed using univariate and multivariate analyses. Results from this study showed that Floristic Quality Index, Auchenorrhyncha Quality Index, as well as other Auchenorrhyncha and plant diversity and integrity index values are greater in high, followed by mid, then low quality hill prairie remnants. Also, these analyses showed that perennial C4 grasses are strongly associated with prairie Auchenorrhyncha. These data suggest that judicious used of prescribed burning or brush removal may be needed to prevent woody-encroachment from eliminating prairie vegetation and Auchenorrhyncha on low quality sites; and restoration of perennial C4 grasses on low quality sites are needed to support more prairie Auchenorrhyncha fauna. Reintroductions of conservative (i.e., prairie-dependent and fire-sensitive) Auchenorrhyncha may also be needed to improve Auchenorrhyncha integrity on mid and low quality sites but these reintroductions need to be used in combination with reduced burn management or the inclusion of unburned refugia to reduce the extirpation of these fire-sensitive insects.
The immatures stages of 8 of the 11 genera (Amastris Stål, Bajulata Ball, Erosne Stål, Harmonides... more The immatures stages of 8 of the 11 genera (Amastris Stål, Bajulata Ball, Erosne Stål, Harmonides Kirkaldy, Idioderma Van Duzee, Neotynelia Creão-Duarte & Sakakibara, Tynelia Stål, and Vanduzea Goding) of the tribe Amastrini are described for the first time along with brief diagnoses of Membracidae and the subfamily Smiliinae. A key to genera and notes on biology are provided. Multiple species of most genera are illustrated. Based on its distinct nymphal morphology, Vanduzea laeta nolina Ball is elevated to specific rank as Vanduzea nolina stat. n., and Bajulata, despite the superficial similarity of its adults to those of Vanduzea, is confirmed as warranting generic rank based on its unique nymphal morphology. Colombia is a new country record for Tynelia.
The brown marmorated stink bug, Halyomorpha halys, a native of Asia, has become a serious invasiv... more The brown marmorated stink bug, Halyomorpha halys, a native of Asia, has become a serious invasive pest in the USA. H. halys was first detected in the USA in the mid 1990s, dispersing to over 41 other states. Since 1998, H. halys has spread throughout New Jersey, becoming an important pest of agriculture, and a major nuisance in urban developments. In this study, we used spatial analysis, geostatistics, and Bayesian linear regression to investigate the invasion dynamics and colonization processes of this pest in New Jersey. We present the results of monitoring H. halys from 51 to 71 black light traps that were placed on farms throughout New Jersey from 2004 to 2011 and examined relationships between total yearly densities of H. halys and square hectares of 48 landscape/land use variables derived from urban, wetland, forest, and agriculture metadata, as well as distances to nearest highways. From these analyses we propose the following hypotheses: (1) H. halys density is strongly associated with urban developments and railroads during its initial establishment and dispersal from 2004 to 2006; (2) H. halys overwintering in multiple habitats and feeding on a variety of plants may have reduced the Allee effect, thus facilitating movement into the southernmost regions of the state by railroads from 2005 to 2008; (3) density of H. halys contracted in 2009 possibly from invading wetlands or sampling artifact; (4) subsequent invasion of H. halys from the northwest to the south in 2010 may conform to a stratified-dispersal model marked by rapid long-distance movement, from railroads and wetland rights-of-way; and (5) high densities of H. halys may be associated with agriculture in southern New Jersey in 2011. These landscape features associated with the invasion of H. halys in New Jersey may predict its potential rate of invasion across the USA and worldwide.