J. Christopher Bergh

J. Christopher Bergh


Research Focus & Metrics

Academic Career Length

26Years (2001-Present)

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

Representative Publications

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24 March 2016 in Environmental Entomology
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Journal Article
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AAAngelita L. Acebes-Doria
Angelita L. Acebes-Doria
TLTracy C. Leskey
Tracy C. Leskey
JBJ. Christopher Bergh
J. Christopher Bergh
Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is a highly polyphagous invasive species and an important pest of orchard crops in the United States. In the Mid-Atlantic region, wild hosts of H. halys are common in woodlands that often border orchards, and H. halys movement from them into orchards poses ongoing management issues. To improve our understanding of host plant effects on H. halys populations at the orchard–woodland interface, nymphal survivorship, developmental duration, and adult fitness (size and fresh weight) on apple (Malus domestica Borkh.), peach (Prunus persica (L.) Batsch), Tree of Heaven (Ailanthus altissima (Mill.) Swingle), and northern catalpa (Catalpa speciosa (Warder)) were examined in laboratory studies. Specifically, we investigated nymphal performance on the foliage and fruiting structures of those hosts and on single- versus mixed-host diets, as well as the effects of host phenology on their suitability. Nymphal performance was poor on a diet of foliage alone, regardless of host. When fruiting structures were combined with foliage, peach was highly suitable for nymphal development and survivorship, whereas apple, Tree of Heaven, and catalpa were less so, although nymphal survival on Tree of Heaven was much greater later in the season than earlier. Mixed-host diets yielded increased nymphal survivorship and decreased developmental duration compared with diets of suboptimal single hosts. Adult size and weight were generally greater when they developed from nymphs reared on mixed diets. The implications of our results to the dispersal behavior, establishment, and management of H. halys are discussed.

1 November 2016 in Crop Protection
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Journal Article
Closed access
AAAngelita L. Acebes-Doria
Angelita L. Acebes-Doria
TLTracy C. Leskey
Tracy C. Leskey
JBJ. Christopher Bergh
J. Christopher Bergh

21 January 2017 in Entomologia Experimentalis et Applicata
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Journal Article
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JBJ. Christopher Bergh
J. Christopher Bergh
William MorrisonWilliam Morrison
William Morrison
SJShimat V. Joseph
Shimat V. Joseph
TLTracy C. Leskey
Tracy C. Leskey
To improve our understanding of adult Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) overwintering biology and to better inform models of its population dynamics, its temporal pattern of spring emergence was investigated using experimental overwintering shelters in screened cages within protective structures. In 2012, plastic shelters containing 100 adults were deployed in unheated, unlighted buildings, and adjacent woodlots in Virginia, USA. In 2013 and 2014, wooden shelters containing 300 paint‐marked adults were deployed in pairs in six woodlots across Virginia, West Virginia, and Maryland, USA; one in a closed cage and one in a cage with the top removed, enabling emerged adults to be counted or to disperse, respectively. In 2013 and 2014, pheromone‐baited and non‐baited pyramid traps encircled the shelters at each site. Regular counts of adults that emerged into the closed cage and of marked and ‘wild’ (unmarked) adults captured in traps were conducted from February or March through early July. In 2012, emergence patterns from shelters in buildings and woodlots were very similar and matched those recorded from woodlots in 2013 and 2014. In all years, a small peak of emergence occurred in about mid‐April, a larger and more prolonged peak was observed between mid‐May and early June, and emergence ended by early July. Of the 449 H. halys adults captured in traps between 2013 and 2014, only three were marked individuals from shelters in the open cage, suggesting that adults emerging from overwintering sites may require a dispersal flight before responding to pheromone‐baited traps. In 2013 and 2014, respectively, 98 and 93% of captures were in pheromone‐baited traps, but there was no correlation between the weekly number of adults that emerged from shelters in the closed cages and captures in traps.

8 May 2021 in Insects
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Journal Article
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JBJ. Christopher Bergh
J. Christopher Bergh
William MorrisonWilliam Morrison
William Morrison
JSJon W. Stallrich
Jon W. Stallrich
BSBrent D. Short
Brent D. Short
JCJohn P. Cullum
John P. Cullum
TLTracy C. Leskey
Tracy C. Leskey
The invasive Halyomorpha halys invades crop fields from various bordering habitats, and its feeding on crops has caused significant economic losses. Thus, H. halys is considered a perimeter-driven threat, and research on alternative management tactics against it has focused on intervention at crop edges. Woodlands adjacent to crop fields contain many hosts of H. halys and are therefore considered “riskiest” in terms of pest pressure and crop injury. However, tree fruit orchards in the Mid-Atlantic, USA, are often bordered on one or more sides by woodlands and other habitats, including other tree fruit blocks, and field crops. Monitoring H. halys using pheromone traps has most often focused on the crop–woodland interface, but the relative effects of woodlands and other habitats bordering orchards on pest pressure and crop injury have not been examined. A two-year study comparing seasonal captures of H. halys and fruit injury among different habitats bordering commercial apple and peach orchards in the Mid-Atlantic revealed that while woodland borders often posed the greatest risk, other border habitats also contributed significantly to captures and injury in numerous instances. The relevance of these findings to refining and optimizing perimeter-based monitoring and management approaches for H. halys is discussed.

1 October 2003 in The Canadian Entomologist
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JBJ. Christopher Bergh
J. Christopher Bergh
TLTracy C. Leskey
Tracy C. Leskey
The dogwood borer,Synanthedon scitula(Harris) (Lepidoptera: Sesiidae), has the broadest host range of the clearwing moths and is considered to be an economically important pest of many ornamental, fruit, and nut trees. Since the 1980s, dogwood borer has been recognized as an increasingly important, indirect pest of apple,Malus domesticaBorkh. (Rosaceae), in eastern North America, owing mainly to increased plantings of apple on size-controlling rootstocks that promote the formation of adventitious root initials (burr knots) on the rootstock and scion. Burr knots appear to be preferred oviposition sites for dogwood borer females, although infestations can also be initiated in wounds, pruning cuts, and crotches on the branches and trunk. Larval feeding in burr knots does not adversely affect the growth and vigor of apple trees, but their mining outward from burr knots into vascular tissue can ultimately cause tree decline and death. Chlorpyrifos is the most effective insecticide for controlling dogwood borer. A supplemental label in the United States permits post-bloom, trunk drench applications of chlorpyrifos specifically for control of borers in apple, with several restrictions that preclude control of infestations higher in the tree. The ongoing review of pesticide tolerances dictated by the 1996 Food Quality Protection Act of the United States of America makes the long-term availability of this chemical uncertain. Cultural practices, such as deeper planting or berming, can reduce the likelihood of infestation of new apple plantings by dogwood borer, although they do not preclude infestations from developing above the graft union. This review and discussion is based on our contention that research toward the development of alternative, behaviorally based management strategies for dogwood borer in apple and other economically important host plants is warranted. Our review and synthesis of the dogwood borer literature revealed important gaps in knowledge about basic aspects of its biology that pertain directly to the development of alternative control tactics based on behavioral manipulation. There is considerable confusion surrounding the sex pheromone of dogwood borer and conflicting results on the response of males to isomers and blends of isomers of its purported pheromone. Studies using sex attractants to monitor its phenology in apple and non-apple habitats have yielded discrepant results and conclusions. Differences in the effectiveness of commercially available pheromone lures for trapping dogwood borer have been reported and the ability of pheromone traps to accurately reflect emergence or population density remains in question. Regardless of pronounced differences in the duration and modality of the seasonal flight of dogwood borer among different geographical regions within its range, the conclusion of univoltinism across most of its range has been perpetuated, based on extremely limited developmental data collected exclusively from individuals that developed on dogwood.

20 April 2017 in Journal of Economic Entomology
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Journal Article
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William MorrisonWilliam Morrison
William Morrison
AAAngelita Acebes-Doria
Angelita Acebes-Doria
EOEmily Ogburn
Emily Ogburn
TKThomas P. Kuhar
Thomas P. Kuhar
JWJames Walgenbach
James Walgenbach
TLTracy C. Leskey
Tracy C. Leskey
The brown marmorated stink bug, Halyomorpha halys (Stål), is an invasive species from Asia capable of causing severe agricultural damage. It can also be a nuisance pest when it enters and exits anthropogenic overwintering sites. In recent years, pheromone lures and traps for H. halys have been developed and used to monitor populations in field studies. To date, no study has investigated the applicability of these monitoring tools for use indoors by building residents during the overwintering period. Herein, we 1) assessed when in late winter (diapause) and spring (postdiapause) H. halys begins to respond to its pheromone (10,11-epoxy-1-bisabolen-3-ol), 2) evaluated whether pheromone-based tools can be used reliably for monitoring H. halys adults in unheated and heated buildings, and 3) elucidated the potential for indoor management using pheromone-baited traps. A 2-yr trapping study suggested that H. halys began to respond reliably to pheromone-baited traps after a critical photoperiod of 13.5 h in the spring. Captures before that point were not correlated with visual counts of bugs in buildings despite robust populations, suggesting currently available pheromone-baited traps were ineffective for surveillance of diapausing H. halys. Finally, because baited traps captured only 8–20% of the adult H. halys known to be present per location, they were not an effective indoor management tool for overwintering H. halys. Our study contributes important knowledge about the capacity of H. halys to perceive its pheromone during overwintering, and the ramifications thereof for building residents with nuisance problems.