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I am broadly interested in biodiversity, plant-pollinator interactions, sustainable and diversified cropping systems, and ecosystem services. My current research project is "Landscapes in Transition", with a particular focus on climate change resilient alternative cropping systems (or, diversified cropping systems), landscape ecology, pests (weeds and insects), and beneficial insects (bees/pollinators).
Mayweed chamomile (Anthemis cotula L.) is a globally invasive, troublesome annual weed but knowledge of its genetic diversity, population structure in invaded regions, and invasion patterns remains unstudied. Therefore, germplasm from 19 A. cotula populations (sites) from three geographically distinct invaded regions: the Walla Walla Basin (located in southern Washington) and the Palouse (located in both northern Idaho and eastern Washington), Pacific Northwest, USA and Kashmir Valley, India were grown in the greenhouse for DNA extraction and sequencing. A total of 18,829 SNPs were called and filtered for each of 89 samples. Pairwise-FST , Nei’s genetic distance, heterozygosity, Wright’s inbreeding coefficient (F), and self-fertilization rates were estimated for populations within and among the three regions with a total of 19 populations comprised of 89 individuals. Overall measurements of genetic variation were low but significant among regions, populations, and individuals. Despite the weak genetic structure, two main genetic clusters were evident, one comprised of populations from Palouse and Kashmir Valley, the other comprised of populations from the Walla Walla Basin. Significant selfing was observed in populations from the Walla Walla Basin and Palouse but not from Kashmir Valley, indicating that Mayweed chamomile in the Pacific Northwest USA could persist with low pollinator or pollen donor densities. Although FST values between the regions indicate Palouse populations are more closely related to Kashmir Valley than to Walla Walla Basin populations. Based on Migrate-n analysis, panmixis was the most likely model, suggesting an unrestricted gene flow among all three regions. Our study indicated that Kashmir Valley populations either originated from or shared the origin with the Palouse populations, suggesting human-mediated migration of A. cotula between regions.
Subodh Adhikari; Samuel R Revolinski; Sanford D Eigenbrode; Ian C Burke. Genetic diversity and population structure of a global invader Mayweed chamomile (Anthemis cotula L.): management implications. AoB PLANTS 2021, 1 .
AMA StyleSubodh Adhikari, Samuel R Revolinski, Sanford D Eigenbrode, Ian C Burke. Genetic diversity and population structure of a global invader Mayweed chamomile (Anthemis cotula L.): management implications. AoB PLANTS. 2021; ():1.
Chicago/Turabian StyleSubodh Adhikari; Samuel R Revolinski; Sanford D Eigenbrode; Ian C Burke. 2021. "Genetic diversity and population structure of a global invader Mayweed chamomile (Anthemis cotula L.): management implications." AoB PLANTS , no. : 1.
Mayweed chamomile (Anthemis cotula L.) is an annual crop weed that has become a substantial impediment to diversify traditional wheat-based cropping systems such as in the Pacific Northwest (PNW), USA. Some of the broadleaf rotational crops are vulnerable to the weed as they are less competitive or lack compatible herbicides for A. cotula management. Although A. cotula has been present in the PNW for more than a century, traits that contribute to invasiveness and how these vary among the weed populations have not been investigated. We assessed trait variation with a common garden greenhouse experiment by comparing 19 A. cotula populations from the PNW and Kashmir Valley, India. Seeds from individual plants from each population were used to grow plants through their senescence. We measured phenological (e.g., flowering duration), morphological (e.g., plant biomass), reproductive fitness (e.g., number of flower heads), and physiological (floral scent VOCs: volatile organic compounds) traits on individual plants and analyzed the data using mixed-effects models. We found high inter-population variation in most of the traits measured, but the variation was not associated with the geographical distance. Seedling emergence within 30 days of planting ranged from 2 to 49% for PNW populations to 55 to 72% for Indian populations. Flowering duration ranged from 2 to 3 months among populations. Other traits such as initial and final flowering dates, the total number of flower heads, and floral scent VOCs also differed among populations. These trait patterns may indicate a localized adaptation of A. cotula populations to environmental or management regimes, variation arising from anthropogenic or natural dispersal, multiple introductions, genetic drift, or combinations of these. Regardless of the processes, the trait variation suggests that weed management plan for A. cotula may need to be tailored to specific locations instead of a uniformly adopted plan across the region.
Subodh Adhikari; Ian C. Burke; Julia Piaskowski; Sanford D. Eigenbrode. Phenotypic Trait Variation in Populations of a Global Invader Mayweed Chamomile (Anthemis cotula): Implications for Weed Management. Frontiers in Agronomy 2021, 3, 1 .
AMA StyleSubodh Adhikari, Ian C. Burke, Julia Piaskowski, Sanford D. Eigenbrode. Phenotypic Trait Variation in Populations of a Global Invader Mayweed Chamomile (Anthemis cotula): Implications for Weed Management. Frontiers in Agronomy. 2021; 3 ():1.
Chicago/Turabian StyleSubodh Adhikari; Ian C. Burke; Julia Piaskowski; Sanford D. Eigenbrode. 2021. "Phenotypic Trait Variation in Populations of a Global Invader Mayweed Chamomile (Anthemis cotula): Implications for Weed Management." Frontiers in Agronomy 3, no. : 1.
Quantification of variation for phenotypic traits within and among weed populations facilitate understanding of invasion mechanisms and management tactics. In the Pacific Northwest (PNW), USA, in response to climate change and to improve sustainability, producers are increasingly adopting broadleaf crops and cover crops, but Mayweed chamomile (Anthemis cotula L.) is a significant barrier to diversifying cropping systems because of its abundance and lack of herbicide options for its control. To quantify within-population phenotypic trait variation and heritability, plants (n = 300) from six half-sib families (i.e., seed source plants or mother plants) from each of 10 A. cotula populations (infested farms or sites) in the PNW were grown from seed through the flowering stage in the greenhouse common garden experiment. We measured percent seedling emergence, the initial date of flowering, flowering duration, plant biomass, number of flower heads, floral scent profiles, and other traits on individual plants. Trait variation was high among half-sib families within each population. For example, in two of the populations, percent seedling emergence within 30 days of planting ranged from 5 to 41% and 3 to 53%, respectively. As another example, initial date of flowering in two other populations ranged from 61 to 93 days and 58 to 92 days, respectively. Differences among half-sib families were greatest for flowering period, which differed by a month in most populations, and floral scent profiles. Heritability estimates were higher than 1.0 for most phenotypic traits, indicating that the study plants were more closely related than half-sibs (i.e., included full-sibs or products of selfing). These patterns of phenotypic trait variation are potentially caused by local edaphoclimatic factors and within-field farm management practices, suggesting that management of A. cotula might be challenging and differ within and across farms.
Subodh Adhikari; Ian C. Burke; Samuel R. Revolinski; Julia Piaskowski; Sanford D. Eigenbrode. Within-Population Trait Variation in a Globally Invasive Plant Species Mayweed Chamomile (Anthemis cotula): Implications for Future Invasion and Management. Frontiers in Agronomy 2021, 3, 1 .
AMA StyleSubodh Adhikari, Ian C. Burke, Samuel R. Revolinski, Julia Piaskowski, Sanford D. Eigenbrode. Within-Population Trait Variation in a Globally Invasive Plant Species Mayweed Chamomile (Anthemis cotula): Implications for Future Invasion and Management. Frontiers in Agronomy. 2021; 3 ():1.
Chicago/Turabian StyleSubodh Adhikari; Ian C. Burke; Samuel R. Revolinski; Julia Piaskowski; Sanford D. Eigenbrode. 2021. "Within-Population Trait Variation in a Globally Invasive Plant Species Mayweed Chamomile (Anthemis cotula): Implications for Future Invasion and Management." Frontiers in Agronomy 3, no. : 1.
Ground beetles (Carabidae) are beneficial insects providing ecosystem services by regulating insect pests and weed seeds. Despite several studies conducted on ground beetles worldwide, there is a lack of knowledge on how these insects are affected by differently managed organic systems (e.g., tillage-based versus grazed-based) compared to that of chemical-based no-tillage conventional cropping systems. In a 5-year (2013–2017) study, we assessed the ground beetle communities in cover crops and winter wheat (Triticum aestivium L.) in Montana, USA, with three contrasting cropping systems: a chemically managed no-tillage, a tillage-based organic, and a livestock-integrated organic with reduced tillage. The first three years (i.e., 2013–2015) corresponded to the transition to organic period, while the last two (i.e., 2016–2017) were conducted in United States Department of Agriculture (USDA) organic-certified tillage-based and livestock-integrated organic systems. The experiment was designed with three management systems across three blocks as the whole plot variable and 5-year rotation of crop phases as the subplot variable. Using pitfall traps, we sampled ground beetles across all cover crop and winter wheat subplots for five years (n = 450). The data were analyzed using mixed effects models and PERMANOVA and visualized with non-metric multidimensional scaling ordination. Our study indicated that organically managed farms, whether tilled or grazed, enhance activity density, species richness, diversity, and evenness of ground beetles in the dryland row crop productions. Also, irrespective of farming system, cover crops supported higher species richness, diversity, and evenness of ground beetles than winter wheat. The ground beetle communities were mostly similar during the transition to organic period. However, during the established organic phase, cropping systems acted as contrasting ecological filters and beetle communities became dissimilar. Cover cropping affected ground beetle communities positively not only in organically managed systems but also in chemical-based conventional systems. Our study provides evidence supporting the adoption of ecologically-based cropping systems such as crop-livestock integration, organic farming, and cover cropping to enhance beneficial insects and their pest-regulation services.
Subodh Adhikari; Fabian D. Menalled. Supporting Beneficial Insects for Agricultural Sustainability: The Role of Livestock-Integrated Organic and Cover Cropping to Enhance Ground Beetle (Carabidae) Communities. Agronomy 2020, 10, 1210 .
AMA StyleSubodh Adhikari, Fabian D. Menalled. Supporting Beneficial Insects for Agricultural Sustainability: The Role of Livestock-Integrated Organic and Cover Cropping to Enhance Ground Beetle (Carabidae) Communities. Agronomy. 2020; 10 (8):1210.
Chicago/Turabian StyleSubodh Adhikari; Fabian D. Menalled. 2020. "Supporting Beneficial Insects for Agricultural Sustainability: The Role of Livestock-Integrated Organic and Cover Cropping to Enhance Ground Beetle (Carabidae) Communities." Agronomy 10, no. 8: 1210.
The recently published article contained several errors in Table 3. The corrected table is provided here.
Arjun Adhikari; Lisa J. Rew; Kumar P. Mainali; Subodh Adhikari; Bruce D. Maxwell. Correction to: Future distribution of invasive weed species across the major road network in the state of Montana, USA. Regional Environmental Change 2020, 20, 1 -2.
AMA StyleArjun Adhikari, Lisa J. Rew, Kumar P. Mainali, Subodh Adhikari, Bruce D. Maxwell. Correction to: Future distribution of invasive weed species across the major road network in the state of Montana, USA. Regional Environmental Change. 2020; 20 (3):1-2.
Chicago/Turabian StyleArjun Adhikari; Lisa J. Rew; Kumar P. Mainali; Subodh Adhikari; Bruce D. Maxwell. 2020. "Correction to: Future distribution of invasive weed species across the major road network in the state of Montana, USA." Regional Environmental Change 20, no. 3: 1-2.
The globally invasive weed, mayweed chamomile (Anthemis cotula L.) is an annual, bushy, ill-scented herb, originating in Eurasia. It is aggressively weedy in croplands, field-side ditches, wet areas and along roadsides, especially in slightly acidic, nitrogen-rich, clay-loam soils. In addition to interfering with crop growth, the weed causes dermatitis and eye irritation in humans, skin rashes and sour mouth in domesticated mammals, and off-flavours in cow's milk through forage contamination. Although A. cotula may be managed effectively with some broadleaf herbicides in cereal crops, it is much more difficult to manage in broadleaved crops and cover crops. In some regions, aggressive use of relatively few herbicides has selected for acetolactate synthase herbicide resistance in A. cotula. Therefore, A. cotula poses serious ecological and economic challenges in many regions. Despite this threat, the details of A. cotula biology and ecology in the context of environmental change remain relatively unknown. For example, the reason for the invasiveness of A. cotula remains uncertain, but is presumed to be due to abundant seed production, allelochemicals, mycorrhizal associations, minimal herbivory in invaded ranges, ability to attract generalist pollinators through an extended flowering period and adaptive capacity in a wide range of soil types and conditions. In this paper, we comprehensively review the literature and ongoing work on A. cotula and provide a research agenda to improve understanding and management of this species.
Subodh Adhikari; Ian C. Burke; Sanford D. Eigenbrode. Mayweed chamomile ( Anthemis cotula L.) biology and management—A review of an emerging global invader. Weed Research 2020, 60, 313 -322.
AMA StyleSubodh Adhikari, Ian C. Burke, Sanford D. Eigenbrode. Mayweed chamomile ( Anthemis cotula L.) biology and management—A review of an emerging global invader. Weed Research. 2020; 60 (5):313-322.
Chicago/Turabian StyleSubodh Adhikari; Ian C. Burke; Sanford D. Eigenbrode. 2020. "Mayweed chamomile ( Anthemis cotula L.) biology and management—A review of an emerging global invader." Weed Research 60, no. 5: 313-322.
Invasive plant species are a significant global problem, with the potential to alter structure and function of ecosystems and cause economic damage to managed landscapes. An effective course of action to reduce the spread of invasive plant species is to identify potential habitat incorporating changing climate scenarios. In this study, we used a suite of species distribution models (SDMs) to project habitat suitability of the eleven most abundant invasive weed species across road networks of Montana, USA, under current (2005) conditions and future (2040) projected climates. We found high agreement between different model predictions for most species. Among the environmental predictors, February minimum temperature, monthly precipitation, solar radiation, and December vapor pressure deficit accounted for the most variation in projecting habitat suitability for most of the invasive weed species. The model projected that habitat suitability along roadsides would expand for seven species ranging from + 5 to + 647% and decline for four species ranging from − 11 to − 88% under high representative concentration pathway (RCP 8.5) greenhouse gas (GHG) trajectory. When compared with current distribution, the ensemble model projected the highest expansion habitat suitability with six-fold increase for St. John’s Wort (Hypericum perforatum), whereas habitat suitability of leafy spurge (Euphorbia esula) was reduced by − 88%. Our study highlights the roadside areas that are currently most invaded by our eleven target species across 55 counties of Montana, and how this will change with climate. We conclude that the projected range shift of invasive weeds challenges the status quo, and requires greater investment in detection and monitoring to prevent expansion. Though our study focuses across road networks of a specific region, we expect our approach will be globally applicable as the predictions reflect fundamental ecological processes.
Arjun Adhikari; Lisa J. Rew; Kumar P. Mainali; Subodh Adhikari; Bruce D. Maxwell. Future distribution of invasive weed species across the major road network in the state of Montana, USA. Regional Environmental Change 2020, 20, 1 -14.
AMA StyleArjun Adhikari, Lisa J. Rew, Kumar P. Mainali, Subodh Adhikari, Bruce D. Maxwell. Future distribution of invasive weed species across the major road network in the state of Montana, USA. Regional Environmental Change. 2020; 20 (2):1-14.
Chicago/Turabian StyleArjun Adhikari; Lisa J. Rew; Kumar P. Mainali; Subodh Adhikari; Bruce D. Maxwell. 2020. "Future distribution of invasive weed species across the major road network in the state of Montana, USA." Regional Environmental Change 20, no. 2: 1-14.
Covering about 40% of Earth’s land surface and sustaining at least 38% of global population, drylands are key crop and animal production regions with high economic and social values. However, land use changes associated with industrialized agricultural managements are threatening the sustainability of these systems. While previous studies assessing the impacts of agricultural management systems on biodiversity and their services focused on more diversified mesic landscapes, there is a dearth of such research in highly simplified dryland agroecosystems. In this paper, we 1) summarize previous research on the effects of farm management systems and agricultural expansion on biodiversity and biodiversity-based ecosystem services, 2) present four case studies assessing the impacts of management systems on biodiversity and ecosystem services across highly simplified dryland landscapes of the Northern Great Plains (NGP), USA, 3) discuss approaches to sustain biodiversity-based ecosystem services in drylands, and 4) present a conceptual framework for enhancing agricultural sustainability in the drylands through research, policy, economic valuation, and adaptive management. An analysis of the land use changes due to agricultural expansion within the Golden Triangle, a representative agricultural area in the NGP, indicated that the proportion of land conversion to agriculture area was 84%, 8%, and 7% from grassland, riparian, and shrubland habitats, respectively. Our results showed this simplification was associated with a potential reduction of pollination services. Also, our economic analysis projected that if 30% parasitism could be achieved through better management systems, the estimated potential economic returns to pest regulation services through parasitoids in Montana, USA alone could reach about $11.23 million. Overall, while dryland agroecosystems showed a significant loss of native biodiversity and its services, greater pest incidence, and a decrease in plant pollinator networks, these trends were moderately reversed in organically managed farming systems. In conclusion, although land use changes due to agricultural expansion and industrialized farming threaten the sustainability of dryland agroecosystems, this impact can be partially offset by coupling ecologically-based farming practices with adaptive management strategies.
Subodh Adhikari; Arjun Adhikari; David Weaver; Anton Bekkerman; Fabian Menalled. Impacts of Agricultural Management Systems on Biodiversity and Ecosystem Services in Highly Simplified Dryland Landscapes. Sustainability 2019, 11, 3223 .
AMA StyleSubodh Adhikari, Arjun Adhikari, David Weaver, Anton Bekkerman, Fabian Menalled. Impacts of Agricultural Management Systems on Biodiversity and Ecosystem Services in Highly Simplified Dryland Landscapes. Sustainability. 2019; 11 (11):3223.
Chicago/Turabian StyleSubodh Adhikari; Arjun Adhikari; David Weaver; Anton Bekkerman; Fabian Menalled. 2019. "Impacts of Agricultural Management Systems on Biodiversity and Ecosystem Services in Highly Simplified Dryland Landscapes." Sustainability 11, no. 11: 3223.
Industrialized farming practices result in simplified agricultural landscapes, reduced biodiversity, and degraded species-interaction networks. Thus far, most research assessing the combined effects of farming systems and landscape complexity on beneficial insects has been conducted in relatively diversified and mesic systems and may not represent the large-scale, monoculture-based dryland agriculture that dominates many regions worldwide. Specifically, the effects of farming systems on forbs, bees, and their interactions are poorly understood in highly simplified dryland landscapes such as those in the Northern Great Plains, United States, an area globally important for conventional and organic small grain, pulse, forage, and oilseed production. During a 3-yr (2013-2015) study, we assessed 1) the effects of dryland no-till conventional and tilled organic farming on forbs, bees, and bee-flower networks and 2) the relationship between natural habitat and bee abundance. Flower density and richness were greater in tilled organic fields than in no-till conventional fields, and forb community composition differed between farming systems. We observed high bee diversity (109 taxa) in this highly simplified landscape, and bee abundance, richness, and community composition were similar between systems. Compared with tilled organic fields, bee-flower interactions in no-till conventional fields were poorly connected, suggesting these systems maintain relatively impoverished plant-pollinator networks. Natural habitat (11% of the landscape) did not affect small-bodied bee abundance in either farming system but positively affected large-bodied bees within 2,000 m of crop-field centers. In highly simplified agricultural landscapes, dryland organic farming and no-till conventional farming together support relatively high bee diversity, presumably because dryland organic farming enhances floral resources and bee-flower networks, and no-till management in conventional farming provides undisturbed ground-nesting habitats for wild bees (Hymenoptera: Apoidea).
Subodh Adhikari; Laura A Burkle; Kevin M O’Neill; David K Weaver; Casey M Delphia; Fabian D Menalled. Dryland Organic Farming Partially Offsets Negative Effects of Highly Simplified Agricultural Landscapes on Forbs, Bees, and Bee-Flower Networks. Environmental Entomology 2019, 48, 826 -835.
AMA StyleSubodh Adhikari, Laura A Burkle, Kevin M O’Neill, David K Weaver, Casey M Delphia, Fabian D Menalled. Dryland Organic Farming Partially Offsets Negative Effects of Highly Simplified Agricultural Landscapes on Forbs, Bees, and Bee-Flower Networks. Environmental Entomology. 2019; 48 (4):826-835.
Chicago/Turabian StyleSubodh Adhikari; Laura A Burkle; Kevin M O’Neill; David K Weaver; Casey M Delphia; Fabian D Menalled. 2019. "Dryland Organic Farming Partially Offsets Negative Effects of Highly Simplified Agricultural Landscapes on Forbs, Bees, and Bee-Flower Networks." Environmental Entomology 48, no. 4: 826-835.
Agricultural intensification has contributed to declines in wild bee populations at local and regional scales. The Northern Great Plains is a key region for small grain, forage, pulse, and oilseed production, yet the impact of available floral resources on colony success of eusocial bees is unknown. To assess the effects of farming system on bee colony success (relative growth rate and fecundity) and worker condition (lipid content and wing wear), we placed 60 mini-colonies of Bombus impatiens in six conventional and six organic spring wheat fields near Big Sandy, Montana, USA over two growing seasons. Consistent with our expectations, we found that flower density and forb richness were positively associated with colony relative growth rate and fecundity. Similarly, flower density, forb richness, and the relative growth rate and fecundity of B. impatiens colonies were greater in organic fields when compared to conventional fields. Workers from organic fields had lower mean wing wear and marginally greater average body lipid content. However, there were no differences in the number of reproductives (queens, workers, and males) between two systems. Lastly, though the overall composition of colony-collected pollen was not different across the farming systems, colony-collected pollen species richness was greater in organic fields in one of the two sampled growing seasons. We conclude that by increasing B. impatiens colony success and individual worker condition, the greater floral resources observed in organic systems can contribute to better biodiversity-based indirect ecosystem services in the highly simplified agricultural landscapes that dominates the Northern Great Plains.
Subodh Adhikari; Laura A. Burkle; Kevin M. O’Neill; David K. Weaver; Fabian D. Menalled. Dryland organic farming increases floral resources and bee colony success in highly simplified agricultural landscapes. Agriculture, Ecosystems & Environment 2018, 270-271, 9 -18.
AMA StyleSubodh Adhikari, Laura A. Burkle, Kevin M. O’Neill, David K. Weaver, Fabian D. Menalled. Dryland organic farming increases floral resources and bee colony success in highly simplified agricultural landscapes. Agriculture, Ecosystems & Environment. 2018; 270-271 ():9-18.
Chicago/Turabian StyleSubodh Adhikari; Laura A. Burkle; Kevin M. O’Neill; David K. Weaver; Fabian D. Menalled. 2018. "Dryland organic farming increases floral resources and bee colony success in highly simplified agricultural landscapes." Agriculture, Ecosystems & Environment 270-271, no. : 9-18.
Farming systems act as ecological filters impacting cropland associated biodiversity; however, the extent of these effects is largely unknown in the drylands of the Northern Great Plains (NGP), a key conventional and organic crop production region. In this 3-year (2013–2015) on-farm study, we addressed this knowledge gap by assessing the effects of conventional and organic farming systems on weed and ground beetle (carabidae) communities. We observed 25 weed species in conventional and 44 in organic fields. Weed species richness and weed species evenness were 237% and 137% greater in organic fields than in conventional fields. We collected a total of 1520 beetle specimens, representing 28 species in conventional and 37 in organic fields. Beetle activity-density and species richness were 220% and 156% greater in organic fields than in conventional fields. Both weed and ground beetle communities differed between conventional and organic fields, indicating that farming systems act as distinct ecological filters. We conclude that, in the drylands of the NGP, adoption of organic farming enhances weed abundance which could have potential management challenges, but provide floral resources to the pollinators and parasitoids. Similarly, greater diversity of ground beetles could enhance conservation biological control of crop pests, ultimately supporting for sustainable agriculture.
Subodh Adhikari; Fabian D. Menalled. Impacts of Dryland Farm Management Systems on Weeds and Ground Beetles (Carabidae) in the Northern Great Plains. Sustainability 2018, 10, 2146 .
AMA StyleSubodh Adhikari, Fabian D. Menalled. Impacts of Dryland Farm Management Systems on Weeds and Ground Beetles (Carabidae) in the Northern Great Plains. Sustainability. 2018; 10 (7):2146.
Chicago/Turabian StyleSubodh Adhikari; Fabian D. Menalled. 2018. "Impacts of Dryland Farm Management Systems on Weeds and Ground Beetles (Carabidae) in the Northern Great Plains." Sustainability 10, no. 7: 2146.
BACKGROUND Cephus cinctus infestation causes $350 million in annual losses in the Northern Great Plains. We compared infestation and parasitism of C. cinctus in spring (including Kamut; Triticum turgidum ssp. turanicum) and winter wheat cultivars grown in organic and conventional fields in Montana, USA. In the greenhouse, we compared C. cinctus preference and survival in Kamut, Gunnison, and Reeder spring wheat cultivars. RESULTS Stems cut by C. cinctus varied by farming system and the seasonality of the wheat crop. No stems of Kamut in organic fields were cut by C. cinctus, but 1.5% [±0.35% standard error (SE)] of stems in conventional spring wheat, 5% (±0.70% SE) of stems in organic winter wheat, and 20% (±0.93% SE) of stems in conventional winter wheat fields were cut by C. cinctus. More larvae of C. cinctus were parasitized in organic (27 ± 0.03% SE) compared with conventional (5 ± 0.01% SE) winter wheat fields. Cephus cinctus oviposition, survival, and the number of stems cut were lowest in Kamut compared with Gunnison and Reeder. CONCLUSION Cephus cinctus infestation was more common in winter wheat than in spring wheat. Organic fields with fewer cut stems also supported more parasitoids. Kamut is a genetic resource for developing C. cinctus‐resistant cultivars. © 2018 Society of Chemical Industry
Subodh Adhikari; Tim Seipel; Fabian D Menalled; David K Weaver. Farming system and wheat cultivar affect infestation of, and parasitism on, Cephus cinctus in the Northern Great Plains. Pest Management Science 2018, 74, 2480 -2487.
AMA StyleSubodh Adhikari, Tim Seipel, Fabian D Menalled, David K Weaver. Farming system and wheat cultivar affect infestation of, and parasitism on, Cephus cinctus in the Northern Great Plains. Pest Management Science. 2018; 74 (11):2480-2487.
Chicago/Turabian StyleSubodh Adhikari; Tim Seipel; Fabian D Menalled; David K Weaver. 2018. "Farming system and wheat cultivar affect infestation of, and parasitism on, Cephus cinctus in the Northern Great Plains." Pest Management Science 74, no. 11: 2480-2487.
Geographical variation in the interacting traits of plant–pollinator mutualism can lead to local adaptive differentiation. We tested Darwin's hypothesis of reciprocal selection as a key driving force for the evolution of floral traits of an alpine ginger (Roscoea purpurea) and proboscis length of a tabanid fly (Philoliche longirostris).We documented the pattern of trait variation in R. purpurea and P. longirostris across five populations. At each site, we quantified pollinator-mediated selection on floral display area, inflorescence height and corolla length of R. purpurea by comparing selection gradients for flowers exposed to natural pollination and to supplemental hand pollination. Reciprocal selection between plant and fly was examined at two sites via the relationship between proboscis length and nectar consumption (fly benefit) and corolla length and pollen deposition (plant benefit).Local corolla tube length was correlated with local fly proboscis length among the five sites. We found strong linear selection imposed by pollinators on corolla tube length at all sites, but there was no consistent relationship of fitness to inflorescence height or floral display area. Selection between corolla length and proboscis length was reciprocal at the two experimental sites examined.The geographical pattern of trait variation and the evidence of selection is consistent with a mosaic of local, species-specific reciprocal selection acting as the major driving force for the evolution of corolla length of R. purpurea and proboscis length of P. longirostris.
Babu Ram Paudel; Mani Shrestha; Martin Burd; Subodh Adhikari; Yong-Shuai Sun; Qing-Jun Li. Coevolutionary elaboration of pollination‐related traits in an alpine ginger ( Roscoea purpurea ) and a tabanid fly in the Nepalese Himalayas. New Phytologist 2016, 211, 1402 -1411.
AMA StyleBabu Ram Paudel, Mani Shrestha, Martin Burd, Subodh Adhikari, Yong-Shuai Sun, Qing-Jun Li. Coevolutionary elaboration of pollination‐related traits in an alpine ginger ( Roscoea purpurea ) and a tabanid fly in the Nepalese Himalayas. New Phytologist. 2016; 211 (4):1402-1411.
Chicago/Turabian StyleBabu Ram Paudel; Mani Shrestha; Martin Burd; Subodh Adhikari; Yong-Shuai Sun; Qing-Jun Li. 2016. "Coevolutionary elaboration of pollination‐related traits in an alpine ginger ( Roscoea purpurea ) and a tabanid fly in the Nepalese Himalayas." New Phytologist 211, no. 4: 1402-1411.
• Premise of the study: Interactions that limit lifetime seed production have the potential to limit plant population sizes and drive adaptation through natural selection. Effects of insect herbivory to apical meristems (apical meristem mining) on lifetime seed production rarely have been quantified experimentally. We studied Cirsium altissimum (tall thistle), whose meristems are mined by Platyptilia carduidactyla (artichoke plume moth), to determine how apical damage affects plant maternal fitness and evaluate both direct and indirect mechanisms underlying these effects.
Subodh Adhikari; F. Leland Russell. Effects of apical meristem mining on plant fitness, architecture, and flowering phenology in Cirsium altissimum (Asteraceae). American Journal of Botany 2014, 101, 2079 -2087.
AMA StyleSubodh Adhikari, F. Leland Russell. Effects of apical meristem mining on plant fitness, architecture, and flowering phenology in Cirsium altissimum (Asteraceae). American Journal of Botany. 2014; 101 (12):2079-2087.
Chicago/Turabian StyleSubodh Adhikari; F. Leland Russell. 2014. "Effects of apical meristem mining on plant fitness, architecture, and flowering phenology in Cirsium altissimum (Asteraceae)." American Journal of Botany 101, no. 12: 2079-2087.