Research and Other Products

February 2014

NOFA- Winter conference, February 17-19, University of Vermont ( Flooding Soil Quality and Cover Crops. Poster at: FloodingandResults_2014.2

Annual Meeting of the Northeast Pasture Consortium in State College, Pa, from February 4 – 6, 2014: Pasture management with keyline ploughing and tillage radish: NEERAPOSTERPPT_JC_reg (Poster Presentation)

Survival of large A. agrestis individuals into the cold season in Vermont. Mega 16(2) – A. agrestis (Journal Paper)

January 2014

Tri-State Greenhouse IPM Workshop Burlington, VT, January 9, 2014 Invasive Earthworms in the Northeastern USA and the Horticultural Trade (by J. Gorres and Margaret Skinner (, Factsheet))

Factsheet on Vermont Act 148 (recycling of organic materials in Vermont) and invasive earthworms. Amynthasagrestis_Act148 (Factsheet)

November  2013

The lab at the 2013 Annual Meeting of the Soil Science Society of America meetings in Tampa, November 4 – 7:

Earthworms increase Oxalate in Jack in the Pulpit corm (Oral Presentation by Ryan Melnichuk and Josef Gorres)

(for PowerPoint Slide Show click here): 2013am

Greenhouse Gas Emissions From Aggregates of a Mesocosm Soil Worked By Lumbricus Rubellus and Amynthas Agrestis.(Poster Presentation by Hüseyin Barış Tecimen, Ryan Melnichuk and Josef Gorres)

(For Poster click here)×44-Template-V7 

Flood Effects On Soil Fertility Along a Microtopographical Gradient (Poster Presentation by Lindsey Ruhl and Josef Gorres)

Abstract: Flooding can cause a variety of soil quality concerns including changes in fertility, increased compaction, and fluctuations in soil biota populations.  Trends of extreme flooding events are increasing with the progression of climate change.  The scope of this preliminary study focuses on soil fertility changes on a micro-topographical scale with an elevation difference of 45 cm.  30 two-inch soil cores were taken from an active agricultural field at three sampling dates and analyzed for OM by LOI, bulk density, moisture, and micro and micro nutrients.  Data shows strong relationships of phosphorus, iron, and potassium with elevation shortly after the flood receded. This relationship did not hold after harvest.   Further study is needed on a larger scale in order to correlate fertility changes along slope with variable rate amendments.

Earthworm Invasion in Northern Forests: Impact On Distribution of Soil Carbon Within Aggregate Fractions (pOSTER pRESENTATION BY mEGHAN kNOWLES, dON rOSS AND jOSEF gORRES)

Abstract: Earthworm invasion into northern forests is a continuous and well documented trend expected to increase substantially over the next few decades.   Most findings document short term carbon losses after an invasion event, primarily through the indirect impact earthworms have on the decomposition rates of these soils.  Other research suggests that earthworm created stable aggregates may mitigate these losses through the long term physical protection of carbon, specifically within microaggregate (2mm), as well as the microaggregate structures occluded within them (<250 µm).   These findings will provide a better understanding of the interactions between earthworms, soil carbon dynamics, and the potential of forest soils to ­sequester carbon.

May 2013:

Blog by Savaş Gönen:

Here are some useful resources for those who want to read:

Classification and Identification of Pheretimoids

Blakemore, R.J., 2012. Japanese earthworms revisited a decade on: (Oligochaeta: Megadrilacea). Zoology in the Middle East, 58(sup4), pp.15-22.


CHANG, C.H., SNYDER, B.A. and SZLAVECZ, K., 2016. Asian pheretimoid earthworms in North America north of Mexico: An illustrated key to the genera Amynthas, Metaphire, Pithemera, and Polypheretima (Clitellata: Megascolecidae). Zootaxa, 4179(3), pp.495-529.


Gates, E.G. and J.W. Reynolds. 2017. Preliminary Key to North American Megadriles (annelida, Oligochaeta), based on external charcteristcs, insofar as possible. Megadrilogica 22.



Distribution of Pheretimoids in the USA


Callaham Jr, M.A., Hendrix, P.F. and Phillips, R.J., 2003. Occurrence of an exotic earthworm (Amynthas agrestis) in undisturbed soils of the southern Appalachian Mountains, USA: The 7th international symposium on earthworm ecology· Cardiff· Wales· 2002. Pedobiologia, 47(5-6), pp.466-470.


Chang, C.H., Johnston, M.R., Görres, J.H., Dávalos, A., McHugh, D. and Szlavecz, K., 2017. Co-invasion of three Asian earthworms, Metaphire hilgendorfi, Amynthas agrestis and Amynthas tokioensis in the USA. Biological Invasions, pp.1-6.


Hendrix, P.F., Callaham Jr, M.A., Drake, J.M., Huang, C.Y., James, S.W., Snyder, B.A. and Zhang, W., 2008. Pandora’s box contained bait: the global problem of introduced earthworms. Annual Review of Ecology, Evolution, and Systematics, 39, pp.593-613.


Keller, R.P., Cox, A.N., Van Loon, C., Lodge, D.M., Herborg, L.M. and Rothlisberger, J., 2007. From bait shops to the forest floor: earthworm use and disposal by anglers. The American Midland Naturalist, 158(2), pp.321-328.


Moore, J.D., Görres, J. and Reynolds, J.W., 2017. Exotic Asian pheretimoid earthworms (Amynthas spp., Metaphire spp.): Potential for colonisation of south-eastern Canada and effects on forest ecosystems. Environmental Reviews.


Reynolds, J.W., Görres, J.H. and Knowles, M.E., 2015. A checklist by counties of earthworms (Oligochaeta: Acanthodrilidae, Lumbricidae and Megascolecidae) in the states of Maine, New Hampshire and Vermont, USA. Megadrilogica, 17(9), pp.125-140.

Ecology of Pheretimoids

Bellitürk, K., Görres, J.H., Kunkle, J. and Melnichuk, R.D.S., 2015. Can commercial mulches be reservoirs of invasive earthworms? Promotion of ligninolytic enzyme activity and survival of Amynthas agrestis (Goto and Hatai, 1899). Applied Soil Ecology, 87, pp.27-31.


Burtelow, A.E., Bohlen, P.J. and Groffman, P.M., 1998. Influence of exotic earthworm invasion on soil organic matter, microbial biomass and denitrification potential in forest soils of the northeastern United States. Applied Soil Ecology, 9(1-3), pp.197-202.


Chang, C.H., Szlavecz, K. and Buyer, J.S., 2017. Amynthas agrestis invasion increases microbial biomass in Mid-Atlantic deciduous forests. Soil Biology and Biochemistry, 114, pp.189-199.


Gates, G.E., 1956. Reproductive organ polymorphism in earthworms of the oriental Megascolecine genus Pheretima Kinberg 1867. Evolution, 10(2), pp.213-227.


Görres, J.H. and Melnichuk, R.D., 2012. Asian invasive earthworms of the genus Amynthas Kinberg in Vermont. Northeastern Naturalist, 19(2), pp.313-322.


Görres, J.H., Connolly, S.T., Chang, C.H., Carpenter, N.R., Keller, E.L., Nouri-Aiin, M. and Schall, J.J., Winter hatching in New England populations of invasive pheretimoid earthworms Amynthas agrestis and Amynthas tokioensis: a limit on population growth, or aid in peripheral expansion?. Biological Invasions, pp.1-5.


Greiner, H.G., Kashian, D.R. and Tiegs, S.D., 2012. Impacts of invasive Asian (Amynthas hilgendorfi) and European (Lumbricus rubellus) earthworms in a North American temperate deciduous forest. Biological Invasions, 14(10), pp.2017-2027.


Hiller, B.J. and Barclay, J.S., 2011. Concentrations of heavy metals in American Woodcock harvested in Connecticut. Archives of environmental contamination and toxicology, 60(1), pp.156-164. Not directly related to Amynthas, but compare with Richardson et al., 2015.


Loss, S.R. and Blair, R.B., 2011. Reduced Density and Nest Survival of Ground‐Nesting Songbirds Relative to Earthworm Invasions in Northern Hardwood Forests. Conservation Biology, 25(5), pp.983-992. This is not a pheretimoid paper but these wildlife effects are likely to occur with Amynthas too.


Qiu, J. and Turner, M.G., 2017. Effects of non-native Asian earthworm invasion on temperate forest and prairie soils in the Midwestern US. Biological Invasions, 19(1), pp.73-88.


Reynolds, J.W., 1974. Are oligochaetes really hermaphroditic amphimictic organisms. Biologist, 56(2), pp.90-99.


Richardson, D.R., Snyder, B.A. and Hendrix, P.F., 2009. Soil moisture and temperature: tolerances and optima for a non-native earthworm species, Amynthas agrestis (Oligochaeta: Opisthopora: Megascolecidae). Southeastern Naturalist, 8(2), pp.325-334.


Richardson, J.B., Görres, J.H., Jackson, B.P. and Friedland, A.J., 2015. Trace metals and metalloids in forest soils and exotic earthworms in northern New England, USA. Soil Biology and Biochemistry, 85, pp.190-198.


Snyder, B.A., Boots, B. and Hendrix, P.F., 2009. Competition between invasive earthworms (Amynthas corticis, Megascolecidae) and native North American millipedes (Pseudopolydesmus erasus, Polydesmidae): effects on carbon cycling and soil structure. Soil Biology and Biochemistry, 41(7), pp.1442-1449.


Snyder, B.A., Callaham Jr, M.A., Lowe, C.N. and Hendrix, P.F., 2013. Earthworm invasion in North America: food resource competition affects native millipede survival and invasive earthworm reproduction. Soil Biology and Biochemistry, 57, pp.212-216.;sequence=1


Snyder, B.A., Callaham, M.A. and Hendrix, P.F., 2011. Spatial variability of an invasive earthworm (Amynthas agrestis) population and potential impacts on soil characteristics and millipedes in the Great Smoky Mountains National Park, USA. Biological Invasions, 13(2), pp.349-358.


Zhang, W., Hendrix, P.F., Snyder, B.A., Molina, M., Li, J., Rao, X., Siemann, E. and Fu, S., 2010. Dietary flexibility aids Asian earthworm invasion in North American forests. Ecology, 91(7), pp.2070-2079.


Ziemba, J.L., Hickerson, C.A.M. and Anthony, C.D., 2016. Invasive Asian Earthworms Negatively Impact Keystone Terrestrial Salamanders. PloS one, 11(5), p.e0151591.


Molecular Ecology

Chang, C.H., Rougerie, R. and Chen, J.H., 2009. Identifying earthworms through DNA barcodes: Pitfalls and promise. Pedobiologia, 52(3), pp.171-180.


Keller, E., J. Schall, J. Görres. 2017. Genetic Structure of Two Invasive Earthworms, Amynthas agrestis and Amynthas tokioensis (Oligochaeta, Megascolecidae) and a molecular method for species identification. Megadrilogica 22: 140-149

Schult, N., Pittenger, K., Davalos, S. and McHugh, D., 2016. Phylogeographic analysis of invasive Asian earthworms (Amynthas) in the northeast United States. Invertebrate Biology, 135(4), pp.314-327.


Pheretimoid Control

Ikeda, H., Callaham Jr, M.A., O’Brien, J.J., Hornsby, B.S. and Wenk, E.S., 2015. Can the invasive earthworm, Amynthas agrestis, be controlled with prescribed fire?. Soil Biology and Biochemistry, 82, pp.21-27.


Colleagues in Wisconsin and my lab are working on this.





European Invasive Earthworm Resources

Adverse effects of Lumbricus terrestris in agriculture

Domínguez, J., Bohlen, P.J. and Parmelee, R.W., 2004. Earthworms increase nitrogen leaching to greater soil depths in row crop agroecosystems. Ecosystems, 7(6), pp.672-685.


Joschko M, Söchtig W and Larink O. 1992. Functional relationship between earthworm burrows and soil water movement in column experiments Soil Biology and Biochemistry 24: 1545-1547.

Shipitalo MJ, Nuutinen V and Butt KR. 2004. Interaction of earthworm burrows and cracks in a clayey, subsurface-drained, soil Applied Soil Ecology 26: 209-217.

Shipitalo, M.J. and Gibbs, F., 2000. Potential of earthworm burrows to transmit injected animal wastes to tile drains. Soil Science Society of America Journal, 64(6), pp.2103-2109.


Shuster, W.D., Shipitalo, M.J., Subler, S., Aref, S. and McCoy, E.L., 2003. Earthworm additions affect leachate production and nitrogen losses in typical midwestern agroecosystems. Journal of environmental quality, 32(6), pp.2132-2139.




Lumbricidae in Forest Ecosystems

Bohlen PJ, Scheu S, Hale CM, et al. 2004. Non-native invasive earthworms as agents of change in northern temperate forests Frontiers in Ecology and the Environment 2: 427-435.


Hale, C., L. Frelich, P. Reich and J. Pastor, 2008: Exotic earthworm effects on hardwood forest floor, nutrient availability and native plants: a mesocosm study. Oecologia 155, 509-518.

Hale, C. M., L. E. Frelich and P. B. Reich, 2005: Exotic European Earthworm Invasion Dynamics in Northern Hardwood Forests of Minnesota, USA. Ecological Applications 15, 848-860.

Holdsworth AR, Frelich LE and Reich PB. 2007. Effects of earthworm invasion on plant species richness in northern hardwood forests.  Conservation Biology 21: 997-1008.

Greenhouse Gases

Speratti, A. B. and J. K. Whalen, 2008: Carbon dioxide and nitrous oxide fluxes from soil as influenced by anecic and endogeic earthworms. Applied Soil Ecology 38, 27-33.”





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16 thoughts on “Research and Other Products

  1. I have reviewed your article to the end. I have difficulty understanding some of the points. I can’t help but say it’s a great article

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