Responses of Acadian Flycatchers (Empidonax virescens) to Hemlock Woolly Adelgid (Adelges tsugae) Infestation in Appalachian Riparian Forests

The Auk ◽  
2009 ◽  
Vol 126 (3) ◽  
pp. 543-553 ◽  
Author(s):  
Michael C. Allen ◽  
James Sheehan ◽  
Terry L. Master ◽  
Robert S. Mulvihill
Keyword(s):  
Hemlock Woolly Adelgid ◽  
Adelges Tsugae ◽  
Riparian Forests ◽  
Empidonax Virescens ◽  
Acadian Flycatchers

scholarly journals Scale-Dependent Habitat use of Acadian FlyCatcher (Empidonax Virescens) in Central Ohio

The Auk ◽  
2006 ◽  
Vol 123 (2) ◽  
pp. 368-382 ◽  
Author(s):  
Marja H. Bakermans ◽  
Amanda D. Rodewald
Keyword(s):  
Habitat Use ◽  
Vegetation Structure ◽  
Spatial Scales ◽  
Riparian Forests ◽  
Matrix Composition ◽  
Multiscale Approach ◽  
Theoretic Approach ◽  
Landscape Matrix ◽  
Empidonax Virescens ◽  
Acadian Flycatchers

Abstract We used a multiscale approach to examine use of riparian forests by Acadian Flycatchers (Empidonax virescens) at three distinct scales: microsite (nest or territory), local stand (3-ha patch of forest), and landscape (1-km-radius area). We examined the extent to which understory arthropod biomass, vegetation structure, and breeding productivity affected habitat use by Acadian Flycatchers across 36 mature riparian forests along an urbanization gradient in central Ohio, 2001–2002. Using an information-theoretic approach, we found that although vegetation structure and understory arthropod biomass were associated with nest and territory location at small spatial scales, they failed to explain habitat use across stands. Instead, percentage of urban cover in the landscape best explained variation in the abundance of Acadian Flycatchers among stands. In fact, Acadian Flycatchers were >3× more abundant in the most rural (≤1% urban) riparian forests than in the more urban (≥10% urban) riparian forests. Nest survival and productivity also declined as urban development increased within the landscape. We suggest that increased nest predation in urban riparian forests, coupled with either reduced productivity or site fidelity or both, may be an underlying mechanism of landscape-scale patterns. Results suggest that explicit consideration of multiple spatial scales, and especially landscape matrix composition, is critical for understanding habitat use. Uso del Hábitat Dependiente de la Escala por parte de Empidonax virescens en el Centro de Ohio

Vegetation dynamics in declining eastern hemlock stands: 9 years of forest response to hemlock woolly adelgid infestation

2006 ◽  
Vol 36 (6) ◽  
pp. 1435-1450 ◽  
Author(s):  
Anne K Eschtruth ◽  
Natalie L Cleavitt ◽  
John J Battles ◽  
Richard A Evans ◽  
Timothy J Fahey
Keyword(s):  
Invasive Plants ◽  
Light Availability ◽  
Hemlock Woolly Adelgid ◽  
Adelges Tsugae ◽  
Eastern Hemlock ◽  
Percent Cover ◽  
Eastern United States ◽  
Transmitted Radiation ◽  
Exotic Invasive ◽  
Exotic Invasive Plants

Hemlock woolly adelgid (HWA; Adelges tsugae Annand) infestations have resulted in the continuing decline of eastern hemlock (Tsuga canadensis (L.) Carrière) throughout much of the eastern United States. In 1994 and 2003, we quantified the vegetation composition and structure of two hemlock ravines in the Delaware Water Gap National Recreation Area. This is the first study to use pre-adelgid disturbance data, annual monitoring of infestation severity, and annual records of hemlock health to assess forest response to HWA infestation. In 2003, 25% of monitored hemlock trees were either dead or in severe decline. Measures of hemlock decline (crown vigor, transparency, density, and dieback) were correlated with HWA infestation severity and changes in light availability over the study period. Average percent total transmitted radiation more than doubled at these sites from 5.0% in 1994 to 11.7% in 2003. The total percent cover of vascular plants increased from 3.1% in 1994 to 11.3% in 2003. Species richness increased significantly, and more species were gained (53) than lost (19) from both ravine floras over the 9-year study period. Though exotic invasive plants were absent from these ravines in 1994, our 2003 resurvey found invasive plants in 35% of the permanent vegetation plots.

scholarly journals The Past, Present, and Future of the Hemlock Woolly Adelgid (Adelges tsugae) and Its Ecological Interactions with Eastern Hemlock (Tsuga canadensis) Forests

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 172 ◽  
Author(s):  
Aaron Ellison ◽  
David Orwig ◽  
Matthew Fitzpatrick ◽  
Evan Preisser
Keyword(s):  
Biological Diversity ◽  
Carbon Sources ◽  
Hemlock Woolly Adelgid ◽  
Adelges Tsugae ◽  
Ecosystem Dynamics ◽  
Eastern Hemlock ◽  
Carbon Sinks ◽  
The North ◽  
Spread Dynamics ◽  
Landscape Scales

The nonnative hemlock woolly adelgid is steadily killing eastern hemlock trees in many parts of eastern North America. We summarize impacts of the adelgid on these forest foundation species; review previous models and analyses of adelgid spread dynamics; and examine how previous forecasts of adelgid spread and ecosystem dynamics compare with current conditions. The adelgid has reset successional sequences, homogenized biological diversity at landscape scales, altered hydrological dynamics, and changed forest stands from carbon sinks into carbon sources. A new model better predicts spread of the adelgid in the south and west of the range of hemlock, but still under-predicts its spread in the north and east. Whether these underpredictions result from inadequately modeling accelerating climate change or accounting for people inadvertently moving the adelgid into new locales needs further study. Ecosystem models of adelgid-driven hemlock dynamics have consistently forecast that forest carbon stocks will be little affected by the shift from hemlock to early-successional mixed hardwood stands, but these forecasts have assumed that the intermediate stages will remain carbon sinks. New forecasting models of adelgid-driven hemlock decline should account for observed abrupt changes in carbon flux and ongoing and accelerating human-driven land-use and climatic changes.

Diversity of proteobacterial endosymbionts in hemlock woolly adelgid (Adelges tsugae) (Hemiptera: Adelgidae) from its native and introduced range

2013 ◽  
Vol 15 (7) ◽  
pp. 2043-2062 ◽  
Author(s):  
Carol D. von Dohlen ◽  
Usha Spaulding ◽  
Kathleen Shields ◽  
Nathan P. Havill ◽  
Cristina Rosa ◽  
...  
Keyword(s):  
Hemlock Woolly Adelgid ◽  
Adelges Tsugae ◽  
Introduced Range

scholarly journals Impact of Imidacloprid for Control of Hemlock Woolly Adelgid on Nearby Aquatic Macroinvertebrate Assemblages

2011 ◽  
Vol 35 (1) ◽  
pp. 26-32 ◽  
Author(s):  
Melissa A. Churchel ◽  
James L. Hanula ◽  
C. Wayne Berisford ◽  
James M. Vose ◽  
Mark J. Dalusky
Keyword(s):  
North Carolina ◽  
Aquatic Invertebrates ◽  
Organic Matter Content ◽  
Adult Emergence ◽  
Hemlock Woolly Adelgid ◽  
Adelges Tsugae ◽  
Matter Content ◽  
Systemic Insecticide ◽  
Aquatic Macroinvertebrate ◽  
Southern Appalachian

Abstract Imidacloprid, a systemic insecticide that acts on the nervous system, is currently being used to control hemlock woolly adelgid (Adelges tsugae Annand), which is damaging hemlock trees. The objective of this study was to determine whether soil injection with imidacloprid for hemlock woolly adelgid control near streams adversely affects aquatic invertebrates. Eastern hemlocks (Tsuga canadensis) in the watersheds surrounding four streams in the southern Appalachian region of Georgia and North Carolina were treated with imidacloprid. Addie Branch was the only stream that exhibited a possible effect from imidacloprid treatment. However, the data followed the same pattern as the other treatment streams, but with a more pronounced decrease in taxa due to adult emergence. Only a trace amount of imidacloprid was detected in one water sample from Holcomb Tributary over a period of 2 years, and no effect was observed on the aquatic macroinvertebrates in that stream. However, caution should be used when applying these results to other areas with different soil types (e.g., low organic matter content) that may not bind imidacloprid as tightly. Our results indicate that soil injections of imidacloprid can safely be used in the southern Appalachian area to control hemlock woolly adelgid.

Combined Effects of Hemlock Woolly Adelgid (Adelges tsugae) Infestation and Treatment with Imidacloprid on Eastern Hemlock (Tsuga canadensis) Leaf Radiometry

2019 ◽  
Vol 117 (4) ◽  
pp. 340-350 ◽  
Author(s):  
Heath W Garris ◽  
Thomas H Settle ◽  
Jonathan E Crossman ◽  
Stephen J Grider ◽  
Shawnté L Michaels
Keyword(s):  
Optical Properties ◽  
Tsuga Canadensis ◽  
Hemlock Woolly Adelgid ◽  
Adelges Tsugae ◽  
Eastern Hemlock ◽  
Abiotic Stressors ◽  
Leaf Optical Properties ◽  
Photosynthetic Potential ◽  
And Control ◽  
Potential Efficiency

Abstract The neonicotinoid systemic insecticide imidacloprid has proven to be an effective treatment for the prevention and control of hemlock woolly adelgid (Adelges tsugae Annand) in southeastern populations of eastern hemlock (Tsuga canadensis L.). Recent studies have demonstrated that imidacloprid and A. tsugae both stimulate salicylic acid-dependent physiological responses in plant tissues responsible for plant defenses against pathogens, timing of developmental outcomes including flowering and leaf senescence, and resilience to abiotic stressors. We evaluated the interacting effects of A. tsugae presence/absence and treatment with imidacloprid on leaf optical properties indicative of photosynthetic potential, photosynthetic efficiency, and tissue senescence. Our results indicated that A. tsugae changes lower canopy leaf optical properties indicative of reduced photosynthetic potential/efficiency and accelerated senescence in mature leaves. Imidacloprid was associated with declines in photosynthetic potential and showed a largely similar, though less pronounced, effect on leaf spectral properties to that of A. tsugae.

Recovery ofSasajiscymnus tsugae, released against hemlock woolly adelgid,Adelges tsugae,in the southern Appalachians

2010 ◽  
Vol 20 (10) ◽  
pp. 1069-1074 ◽  
Author(s):  
Abdul Hakeem ◽  
Jerome F. Grant ◽  
Paris L. Lambdin ◽  
David Buckley ◽  
Frank A. Hale ◽  
...  
Keyword(s):  
Hemlock Woolly Adelgid ◽  
Adelges Tsugae ◽  
Southern Appalachians

scholarly journals Temporal Asynchrony of Adult Emergence Between Leucopis argenticollis and Leucopis piniperda (Diptera: Chamaemyiidae), Predators of the Hemlock Woolly Adelgid (Hemiptera: Adelgidae), with Implications for Biological Control

2020 ◽  
Vol 49 (4) ◽  
pp. 823-828
Author(s):  
Alex N Neidermeier ◽  
Darrell W Ross ◽  
Nathan P Havill ◽  
Kimberly F Wallin
Keyword(s):  
Biological Control ◽  
North America ◽  
Pacific Northwest ◽  
Adult Emergence ◽  
Hemlock Woolly Adelgid ◽  
Adelges Tsugae ◽  
Tsuga Heterophylla ◽  
Eastern North America ◽  
Biological Control Agents ◽  
The Pacific

Abstract Two species of silver fly, Leucopis argenticollis (Zetterstedt) and Leucopis piniperda (Malloch) (Diptera: Chamaemyiidae), from the Pacific Northwest region of North America have been identified as potential biological control agents of hemlock woolly adelgid (Hemiptera: Adelgidae: Adelges tsugae Annand) in eastern North America. The two predators are collectively synchronized with A. tsugae development. To determine whether adult emergence of the two species of silver fly are also synchronized with one another, we collected adult Leucopis which emerged from A. tsugae-infested western hemlock [Pinaceae: Tsuga heterophylla (Raf.) Sarg.] from four sites in the Pacific Northwest over a 29-d period. Specimens were collected twice daily in the laboratory and identified to species using DNA barcoding. The study found that more adult Leucopis were collected in the evening than the morning. Additionally, the daily emergences of adults over the 29-d sampling period exhibited sinusoidal-like fluctuations of peak abundance of each species, lending evidence to a pattern of temporal partitioning. This pattern could have logistical implications for their use as biological control agents in eastern North America, namely the need to release both species for maximum efficacy in decreasing A. tsugae populations.

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