Joshua Campbell

Dr. Joshua Campbell

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Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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8 February 2007 in Journal of Insect Conservation
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Journal Article
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JCJoshua Campbell
Joshua Campbell
JHJ. L. Hanula
J. L. Hanula

1 January 2007 in Biological Conservation
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Journal Article
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JCJoshua Campbell
Joshua Campbell
JHJ.L. Hanula
J.L. Hanula
TWT.A. Waldrop
T.A. Waldrop

1 March 2006 in Quaternary Research
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Journal Article
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LSLora R. Stevens
Lora R. Stevens
JSJeffery R. Stone
Jeffery R. Stone
JCJoshua Campbell
Joshua Campbell
SFSherilyn C. Fritz
Sherilyn C. Fritz
A 2200-yr long, high-resolution (∼5 yr) record of drought variability in northwest Montana is inferred from diatoms and δ18O values of bio-induced carbonate preserved in a varved lacustrine core from Foy Lake. A previously developed model of the diatom response to lake-level fluctuations is used to constrain estimates of paleolake levels derived from the diatom data. High-frequency (decadal) fluctuations in the de-trended δ18O record mirror variations in wet/dry cycles inferred from Banff tree-rings, demonstrating the sensitivity of the oxygen-isotope values to changes in regional moisture balance. Low frequency (multi-centennial) isotopic changes may be associated with shifts in the seasonal distribution of precipitation. From 200 B.C. to A.D. 800, both diatom and isotope records indicate that climate was dry and lake level low, with poor diatom preservation and high organic carbon: nitrogen ratios. Subsequently, lake level rose slightly, although the climate was drier and more stable than modern conditions. At A.D. 1200, lake level increased to approximately 6 m below present elevation, after which the lake fluctuated between this elevation and full stage, with particularly cool and/or wetter conditions after 1700. The hydrologic balance of the lake shifted abruptly at 1894 because of the establishment of a lumber mill at the lake's outlet. Spectral analysis of the δ18O data indicates that severe droughts occurred with multi-decadal (50 to 70 yr) frequency.

1 January 2011 in Invertebrate Systematics
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JLJoel Ledford
Joel Ledford
PPPierre Paquin
Pierre Paquin
JCJames Cokendolpher
James Cokendolpher
JCJoshua Campbell
Joshua Campbell
CGCharles Griswold
Charles Griswold
A phylogenetic analysis of the spider genus Neoleptoneta Brignoli, 1972 is presented based on molecular sequence variation from three genes (mitochondrial cytochrome c oxidase subunit I, nuclear histone H3 and nuclear 28S rDNA) and including exemplars for all North American leptonetid genera except the ecribellate archoleptonetine Darkoneta. Analysis of concatenated data and independent genes using Bayesian, maximum likelihood and parsimony methods failed to recover Neoleptoneta as monophyletic. The genera Archoleptoneta, Appaleptoneta and Calileptoneta are monophyletic and a sister group relationship is supported between Appaleptoneta and Calileptoneta. Morphological data based on a survey of leptonetid genera using scanning electron and compound light microscopy are discussed and traced on the molecular phylogeny. Images for each North American leptonetine genus are provided, including comparison with Asian and European outgroups. Images of the incertae sedis species Leptoneta brunnea Gertsch, 1974 and Leptoneta sandra Gertsch, 1974 are provided and their generic placement is re-evaluated. Ancestral state reconstruction is used to assess patterns of cave evolution and shows that most species are descended from troglophilic ancestors and that troglobites have evolved at least nine times independently within the North American Leptonetidae. Neoleptoneta is relimited to include seven species restricted to central Mexico including N. bonita (Gertsch, 1974), N. capilla (Gertsch, 1971), N. delicata (Gertsch, 1971), N. limpida (Gertsch, 1974), N. rainesi (Gertsch, 1971) and N. reclusa (Gertsch, 1971) and to include Leptoneta brunnea, giving the new combination N. brunnea (Gertsch, 1974). The remaining species described in Neoleptoneta are placed in three new genera: (1) Chisoneta, gen. nov. from south-western Texas and Nuevo Leon, Mexico, including the four species C. chisosea (Gertsch, 1974), C. isolata (Gertsch, 1971), C. modica (Gertsch, 1974) and C. pecki (Gertsch, 1971), new combinations; (2) Ozarkia, gen. nov. from Arizona and New Mexico north-east to Arkansas, Alabama and Georgia, including the nine species O. alabama (Gertsch, 1974), O. apachea (Gertsch, 1974), O. archeri (Gertsch, 1974), O. arkansa (Gertsch, 1974), O. blanda (Gertsch, 1974), O. georgia (Gertsch, 1974), O. ivei (Gertsch, 1974), O. novaegalleciae (Brignoli, 1979) and O. serena (Gertsch, 1974), new combinations; and (3) Tayshaneta, gen. nov. from Texas south to Coahuila, Mexico, with the eleven species T. anopica (Gertsch, 1974), T. bullis (Cokendolpher, 2004), T. coeca (Chamberlin & Ivie, 1942), T. concinna (Gertsch, 1974), T. devia (Gertsch, 1974), T. furtiva (Gertsch, 1974), T. microps (Gertsch, 1974), T. myopica (Gertsch, 1974), T. paraconcinna (Cokendolpher & Reddell, 2001), T. uvaldea (Gertsch, 1974) and T. valverdae (Gertsch, 1974), new combinations. Leptoneta sandra Gertsch, 1974 cannot be placed in any North American, European or Asian genus and is thus transferred to the new genus Montanineta, gen. nov., giving the new combination Montanineta sandra (Gertsch, 1974).

24 August 2016 in Journal of Economic Entomology
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JCJoshua Campbell
Joshua Campbell
ACAna R. Cabrera
Ana R. Cabrera
CSCory Stanley-Stahr
Cory Stanley-Stahr
Jamie EllisJamie Ellis
Jamie Ellis
Flupyradifurone (Sivanto) is a novel systemic insecticide from the butenolide class developed by Bayer. Based on available data (USEPA [2014][1]), this insecticide appears to have a favorable safety profile for honey bee colonies. As a result, the label permits the product to be applied during prebloom and bloom in various crops, including citrus, except when mixed with azole fungicides during the blooming period. We placed 24 honey bee ( Apis mellifera L.) colonies adjacent to eight flowering buckwheat ( Fagopyrum esculentum Moench) fields that either had been sprayed with the maximum label rate of flupyradifurone or with water only (control fields), with three colonies placed adjacent to each field. We conducted colony strength assessments during which the number of adult bees, eggs, uncapped brood cells, capped brood cells, food storage cells, and weights of honey supers and brood chambers were determined prior to, during, and after the flowering period. We also analyzed bee-collected pollen and nectar for flupyradifurone residues. Overall, there were no differences in any colony strength parameter for colonies placed at control and flupyradifurone-treated buckwheat fields. Residue analyses showed that pollen ( x = 565.8 ppb) and nectar ( x = 259.4 ppb) gathered by bees on fields treated with flupyradifurone contained significantly higher flupyradifurone residues than did bee bread and unprocessed nectar collected by bees from control fields (75% of samples <LOD). Within the conditions set forth by our experimental design, our collective data suggest no adverse effects of flupyradifurone on honey bee colonies when following label directions. [1]: #ref-29

21 April 2018 in Forest Science
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JCJoshua Campbell
Joshua Campbell
PVPatrick A Vigueira
Patrick A Vigueira
CVCynthia C Viguiera
Cynthia C Viguiera
CGCathryn H Greenberg
Cathryn H Greenberg
We investigated the effects of repeated prescribed fire, mechanical thinning, and combinations of fire and mechanical thinning on pollinators and flower visitors within the herbaceous understory and midstory of a temperate forest in North Carolina. Using colored pan traps, we sampled flower visitors during the plant growing season between 2014 and 2016. We captured 5,520 flower visitors that were dominated by halictid bees and vespid wasps. Twenty genera of bees representing at least 30 species were captured within our experimental plots. Within the forest understory, we found higher abundances and diversities of bees and other flower visitors within plots that had been treated with prescribed fire or a combination of mechanical thinning and prescribed fire compared to control plots. Within our midstory samples, we found that forest management practices did not affect the abundance of any common flower visitor species/family. However, Augochlora pura and Vespula spp. were more abundant in the midstory compared to the forest understory. Overall, our study demonstrates that repeated applications of prescribed fire maintained elevated abundances and diversity of bees and other flower-visiting insects compared to untreated plots, likely due to increased herbaceous plant diversity and enhanced quality of nesting habitat within the understory. Our results also indicate that many flower visitors utilize the midstory of a temperate forest potentially for foraging habitat.