About

Scott Salom is a Professor and Graduate Program Director in the Department of Entomology at Virginia Tech. His research focuses on integrated pest management of forest insect and weed pests, with particular emphasis on non-native invaders. His work involves the development, implementation, and assessment of classical and augmentative biological control programs. Salom's principal projects include studying, rearing, releasing, and evaluating impacts of imported predators of the hemlock woolly adelgid (HWA), which causes large-scale decline and mortality of eastern and Carolina hemlocks. He also evaluates biological control agents for the tree of heaven, an invasive weed that displaces native vegetation and serves as a host for spotted lanternfly. His research includes the use of native fungi as bioherbicides and the restoration of sites following removal of invasive species. Salom has contributed to the understanding and management of forest pests through his work on biological studies, field releases, and impact assessments of various predator species, as well as bioherbicide development. He has been involved in multiple funded projects supported by agencies such as the USDA Forest Service and the Virginia Department of Forestry. Salom is a member of several professional organizations, including the Entomological Society of America and the International Organization of Biological Control.

Research topics

• Biology
• Ecology
• Botany
• Horticulture
• Biotechnology
• Demography

Selected publications

• Active Revegetation of Ailanthus altissima Stands Treated with the Bioherbicide Verticillium nonalfalfae is Met with Limited Success

  Natural Areas Journal · 2026-04-22

  article
  PublisherDOI

• Potential feeding deterrents of Adelges tsugae found in biological control flies

  Die Naturwissenschaften · 2025-06-01

  articleOpen accessSenior author

  The invasive hemlock woolly adelgid, Adelges tsugae (HWA, Hemiptera: Adelgidae), is a detrimental pest to native eastern and Carolina hemlocks. In the last 2 decades, biological control utilizing two species of Laricobius beetles (Coleoptera: Derodontidae) has been of focus in the widespread effort to control HWA. Recently, two species of silver flies, native to the Pacific Northwest, Leucotaraxis argenticollis Zetterstedt and Leucotaraxis piniperda Malloch (Diptera: Chamaemyiidae), are being investigated as additional biological control agents. Releasing these two silver fly species in the eastern United States has yet to result in the establishment of these predators. During laboratory studies, Leucotaraxis larvae excreted a black substance in response to being disturbed, which contained anthraquinones previously detected in HWA. Previous research on Laricobius spp. found that the beetles likely sequestered these compounds from HWA. These compounds are feeding deterrents in other insect species. Leucotaraxis argenticollis life stages, their excrement, and honeydew produced by HWA were collected and analyzed by gas chromatography-mass spectrometry. Results showed that these anthraquinones were detected in various life stages of Le. argenticollis immatures and adults that fed on HWA. They were not detected in Le. argenticollis adults that were only fed artificial diet and water, indicating that Le. argenticollis sequesters the anthraquinones from HWA and may transmit the compounds to their eggs.

  PublisherOA PDFDOI

• Twenty-Two-Year Study of the Spread and Impact of Hemlock Woody Adelgid and Elongate Hemlock Scale in Southwest Virginia

  Journal of Forestry · 2025-01-01 · 4 citations

  articleOpen accessSenior author

  Abstract This 22-year study examined the impact and dispersal of the hemlock woolly adelgid (HWA) and the elongate hemlock scale at 67 sites in southwest Virginia. A hemlock stand health index was based on percent foliage density, live crown ratio, live branches, live tips, new foliage, and live trees at each site. At the beginning of the study, hemlock health at all sites was good. After 22 years hemlock health had declined to a poor condition and mortality averaged 30%. Differences in health decline were found among the three physiographic mountain regions. Analysis of the variables measured indicated that hemlock stand health decline was positively correlated with the percentage of branches infested with HWA, hemlock diameter at breast height (dbh), and total tree basal area per hectare and negatively correlated with latitude. Crown density, the inverse of Forest Inventory and Analysis (FIA) canopy foliage transparency could be used as a standalone hemlock health measurement.

  PublisherOA PDFDOI

• Range Expansion of a <i>Verticillium nonalfalfae</i> Isolate Suppresses <scp><i>Ailanthus altissima</i></scp> With Variable Results Along Environmental Gradients

  Forest Pathology · 2025-03-10 · 1 citations

  articleOpen accessSenior author

  ABSTRACT Verticillium nonalfalfae has been studied for &gt; 20 years as a potential fungal bioherbicide for Ailanthus altissima . A specific isolate from Pennsylvania, VnAa140, has desirable virulence properties and demonstrated host specificity. However, it has yet to be tested outside Pennsylvania, and the potential for regional variation in the host–pathogen interaction and possible environmental limitations are unknown. The range of VnAa140 was expanded for the first time by inoculating A. altissima across 10 sites in Virginia that spanned three physiographic provinces and four USDA hardiness zones with the intent of quantifying disease progression in inoculated trees and the spread of the pathogen throughout A. altissima stands. However, initial inoculations resulted in very little disease development. Reinoculations the following year induced much higher levels of disease and mortality, including 52.3% ± 4.2% increase in disease levels of inoculated trees and a 27.2% ± 10.2% increase in symptom development among uninoculated trees, a marker of pathogen spread. However, results ranged widely along macro and microclimatic gradients, with higher site average temperatures and warmer microsite conditions correlating negatively with disease levels. While VnAa140 remains a strong bioherbicide candidate for the control of A. altissima , it appears that variability by culture and attenuation of virulence traits also contributed to the different levels of host disease development we observed in the field, suggesting that procedures to prevent and screen for these issues will be required as the fungus is propagated for bioherbicide formulation on a commercial scale.

  PublisherOA PDFDOI

• Feeding and oviposition studies of <i>Leucotaraxis</i> spp. (Diptera: Chamaemyiidae), predators of hemlock woolly adelgid (Hemiptera: Adelgidae), in relation to increasing prey densities

  Environmental Entomology · 2025-11-30

  articleSenior author

  Two species of Leucotaraxis Gaimari & Havill (Diptera: Chamaemyiidae), predators of hemlock woolly adelgid, Adelges tsugae Annand (HWA, Hemiptera: Adelgidae) on western hemlock, Tsuga heterophylla (Raf.) Sarg. (Pinales: Pinaceae), in western North America, are currently being investigated as potential biological control agents for HWA in eastern North America. To evaluate their potential for biological control of HWA on eastern hemlock, Tsuga canadensis (L.) Carrière (Pinales: Pinaceae), we conducted laboratory studies to assess their feeding and oviposition responses to different HWA densities. Leucotaraxis argenticollis Zetterstedt was only assessed on the first of 2 generations of HWA, while Leucotaraxis piniperda Malloch was assessed on both generations of HWA, as their phenology in the eastern United States is unknown. Increasing prey densities of HWA ovisacs were used to assess the oviposition of both species of silver flies. Leucotaraxis argenticollis significantly increased their oviposition in response to an increase in HWA densities on the sistens ovisacs containing progrediens eggs, while Le. piniperda showed no significant response for either generation of HWA. Overall, there was no difference in oviposition rates between species; however, Le. argenticollis laid their eggs more frequently on or under the ovisac than Le. piniperda. Increasing prey densities of HWA ovisacs were utilized to assess the feeding response of Le. argenticollis larval feeding. Leucotaraxis argenticollis significantly increased their feeding in response to increased prey densities. These laboratory studies suggest Le. argenticollis has potential as a biological control agent, and both species warrant further investigation.

  PublisherDOI

• Observation of key phenological stages of hemlock woolly adelgid (Hemiptera: Adelgidae): using citizen science as a tool to inform research and management

  Journal of Economic Entomology · 2024-03-28 · 2 citations

  article

  Increasing efficiency of data gathering at the landscape scale on the growing number of pests and pathogens threatening forests worldwide has potential to improve management outcomes. Citizen science is expanding, with growing support and utility in environmental and conservation fields. We present a case study showing how citizen science observations can be used to inform research and management of a devastating forest pest. Hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), was introduced to eastern North America, leading to decline and mortality of eastern [Tsuga canadensis (L.) Carrière] (Pinales: Pinaceae) and Carolina hemlock (Tsuga caroliniana Engelmann) trees. Management activities, most notably biological control, rely on observations of A. tsugae phenology to inform the timing of releases and monitoring surveys of their highly synchronized specialist predators. In this article, we outline a citizen science program and report phenological observations on A. tsugae. Additionally, we report data comparing A. tsugae estivation break in Virginia (VA) and New York (NY) State, revealing that estivation break is synchronized between NY and VA. This observation is supported by 6 years of citizen scientist observations, showing similar patterns throughout NY, with egg laying shown to be much more variable than estivation break.

  PublisherDOI

• The impact of imidacloprid on the subterranean survivorship of <i>Laricobius</i> (Coleoptera: Derodontidae), a biological control agent of <i>Adelges tsugae</i> (Hemiptera: Adelgidae)

  Agricultural and Forest Entomology · 2024-08-21 · 1 citations

  articleOpen accessSenior author

  Abstract 1. The invasive hemlock woolly adelgid (HWA), Adelges tsugae (Annand) (Hemiptera: Adelgidae), has spread throughout most of the range of eastern hemlock, Tsuga canandensis (L.), and the entire range of Carolina hemlock, Tsuga caroliniana (Engelman), in the United States. 2. Integrated pest management (IPM) of HWA combines chemical applications with the release of biological control agents on untreated trees within the same stand. Laricobius spp., Rosenhauer (Coleoptera: Derodontidae), have been used as biological control agents of HWA since 2003 and have subterranean and arboreal life phases that are synchronous with HWA's lifecycle. When utilizing IPM tactics, there is potential for Laricobius spp. to settle below an insecticide‐treated tree for its subterranean phase. 3. Field investigations assessed the impact of historical (five years post treatment in 2017) and recent imidacloprid soil treatments (via soil injection, soil drench, and tablet in November 2020) on the subterranean survivorship of Laricobius spp. by quantifying concentrations of imidacloprid and its metabolites to determine its potential impact on percent adult emergence from the soil. 4. We observed a significant treatment effect on mean soil concentration among application methods at the recent treatment site, but not the historical treatment site. Additionally, at the more recently treated site, significantly lower mean percent emergence was observed from soil drench and tablet imidacloprid applications after one year (2021), but by the following year (2022), that effect was no longer present. 5. This study supports recent recommendations to delay releases of Laricobius spp. for one‐year post‐treatment with imidacloprid. Furthermore, these data suggest when applying imidacloprid to a stand established with Laricobius spp., soil injection techniques pose the least risk to their subterranean survivorship.

  PublisherOA PDFDOI

• A review of potential biological controls for <i>Ailanthus altissima</i>

  Annals of the Entomological Society of America · 2024-11-18 · 3 citations

  reviewOpen access

  Abstract Ailanthus altissima (Mill.) Swingle (Sapindales: Simaroubaceae) (tree-of-heaven) is an invasive tree species first introduced to the United States in 1784. With high rates of sexual reproduction, rapid growth, and prolific vegetative sprouting, A. altissima is an aggressive competitor that reduces native plant diversity and is difficult to manage beyond small-scale infestations. In the United States, the issues associated with Ailanthus management were compounded by the 2014 arrival of Lycorma delicatula (spotted lanternfly). Lycorma delicatula coevolved with A. altissima, its primary host, in eastern Asia. Suppression of A. altissima is recommended as an important strategy to slow the spread of L. delicatula. Due to the inadequacy of traditional control methods to manage A. altissima, biological controls are desired. Several potential biological control agents have been proposed for A. altissima. This review discusses current research on several promising candidates, specifically a native fungus, Verticillium nonalfalfae Inderb. et al. (Hypocreales: Plectosphaerellaceae); a trunk-boring beetle, Eucryptorrhynchus brandti (Harold) (Coleoptera: Curculionidae: Cryptorrhynchinae); and an eriophyid mite, Aculops ailanthi (Lin-Fuping, Jin-Changle &amp; Kuang-Haiya) (Arachnida: Eriphyidae). A list of other possible biological control agents is also provided. We discuss unanswered questions for each species, the limits of biological controls in this system, and call for further research on integrated pest management practices for managing A. altissima.

  PublisherOA PDFDOI

• Laboratory assessment of predation and fecundity of <i>Laricobius</i> species (Coleoptera: Derodontidae), predators of hemlock woolly adelgid

  Biocontrol Science and Technology · 2024-10-01 · 1 citations

  articleSenior author
  PublisherDOI

• The bioherbicide <i>Verticillium nonalfalfae</i> effectively removes tree-of-heaven (<i>Ailanthus altissima</i>) but leaves many other non-native plants

  Invasive Plant Science and Management · 2024-10-29 · 3 citations

  articleOpen accessSenior author

  Abstract Tree-of-heaven [ Ailanthus altissima (Mill.) Swingle] readily exploits disturbances, grows quickly into dense monocultures, and suppresses native plant species. The vascular wilt pathogen, Verticillium nonalfalfae , native to the eastern United States, has been proposed as a biocontrol agent for the invasive A. altissima. Studies consistently demonstrate the safety and efficacy of the bioherbicide, but they also note that the selective nature of the fungus does not preclude other invasive plants that commonly co-occur with A. altissima from occupying the site. We quantified the standing plant community and seedbank at several sites across Virginia 5 yr after inoculation with V. nonalfalfae to understand which species are present or being naturally recruited . Ailanthus altissima remained dominant in untreated areas but was nearly eradicated from the treatment plots. Other non-native species made up a large portion of the plant community and seedbank across all study areas, with no differences in their respective cover and count between treatments. While variability in plant community composition is high and site-specific context is important for establishing effective management strategies, planting native species and mitigating other invasives will be crucial to ensuring native species successfully establish in bioherbicide-treated areas.

  PublisherOA PDFDOI

Frequent coauthors

• Loke T. Kok

  Virginia Tech

  49 shared

• T. L. Payne

  32 shared

• C. Wayne Berisford

  University of Georgia

  30 shared

• Thomas J. McAvoy

  Virginia Tech

  29 shared

• Jeffrey G. Fidgen

  22 shared

• Nathan P. Havill

  Northern Research Station

  19 shared

• David E. Legg

  18 shared

• A. Ascoli‐Christensen

  University of Arizona

  17 shared

Labs

• Scott Salom LabPI

Awards & honors

• Recipient, President’s Prize Award for outstanding student p…
• Sigma Xi Grant-in-Aid Research Award (1993)
• VT Grad Res. Assoc. Res. Grant (1994)
• James Grayson Scholarship for Outstanding Ph.D. student in D…
• James Grayson Scholarship for Outstanding Ph.D. Student in D…