scholarly journals Maximizing Oviposition Efficiency when Mass Rearing the Coccinellid,Sasajiscymnus tsugae,a Predator of the Hemlock Woolly Adelgid,Adelges tsugae

2010 ◽  
Vol 10 (152) ◽  
pp. 1-9 ◽  
Author(s):  
Hugh E. Conway ◽  
Joseph D. Culin ◽  
LayLa W. Burgess ◽  
Cora Allard
Keyword(s):  
Mass Rearing ◽  
Hemlock Woolly Adelgid ◽  
Adelges Tsugae ◽  
Sasajiscymnus Tsugae

Comparison of two different box styles for mass rearing of Sasajiscymnus tsugae (Coleoptera: Coccinellidae), a biological control agent of hemlock woolly adelgid (Hemiptera: Adelgidae)

2005 ◽  
Vol 137 (5) ◽  
pp. 622-629 ◽  
Author(s):  
Huge E. Conway ◽  
Karen B. Burton ◽  
Carolyn A. Hendrix ◽  
LayLa W. Burgess ◽  
Joseph D. Culin
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Mass Rearing ◽  
Hemlock Woolly Adelgid ◽  
Control Agent ◽  
Adelges Tsugae ◽  
Production Costs ◽  
Significant Difference ◽  
Sasajiscymnus Tsugae ◽  
Time Required

AbstractThe hemlock woolly adelgid (HWA), Adelges tsugae Annand, is the number one threat to hemlock (genus Tsuga Carr.; Pinaceae) forests in eastern North America. Sasajiscymnus tsugae (Sasaji et McClure), an introduced coccinellid from Japan, is a promising biological control agent for HWA. In mass rearing of S. tsugae, the main goals are to maximize adult beetle production, reduce the amount of human labor, and minimize production costs. Significantly higher adult S. tsugae production and survivorship from egg to adult were observed in a modified rearing box compared with a conventional rearing box. The 30 modified boxes produced 4400 more beetles than the 30 conventional boxes. Over time, egg to adult survivorship decreased because of larval cannibalism at densities above 1650 larvae per rearing box. Additionally, warmer weather conditions increased the number of insect and spider predators incidentally introduced via HWA-infested hemlock twigs. There was no significant difference in the time required to prepare modified and conventional boxes for initial introduction of eggs, but significantly less time was required to add water, honey, and HWA-infested twigs to the modified boxes. The additional cost and time required to add modifications to each box was compensated for by the increased number of adult S. tsugae produced and the time saved during the 35 days of scheduled maintenance as eggs hatched and larvae developed to adults.

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
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