Asian earthworm invasion

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In recent years, there has been a rising concern over the invasion of Asian pheretimoid earthworms in North America, particularly of the genera Amynthas and Metaphire, in North America.[1] These earthworms have a variety of nicknames due to their characteristic thrashing behavior, and are commonly referred to as "jumping worms," "Alabama jumpers," "crazy snake worms," and "Asian worms." The effects of invasive Asian earthworm species are much less documented than that of European lumbricid earthworms, but there greater concern over the potential effects of jumping worms on soil structure and chemistry, nutrient cycling, forest regeneration and animal and plant communities.[1] Evidence shows that Asian earthworms grow more rapidly,[2] reproduce more quickly, and have greater flexibility in their diet than European species,[3] potentially making them superior competitors to the pre-existing European earthworms. These characteristics, along with their observed ability to exist at higher densities, means that jumping worms can consume organic matter more rapidly, stripping the forest floor of the organic matter and temporarily flooding the system with nutrients. Northeastern forests evolved under the slow decomposition and release of nutrients, and it is still unclear how forests are and will respond to the rapid break down of organic material.

Prevention[edit]

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At this point there is no known way to remove the earthworms from the soil, so proposals have focused on ways to slow their spread. One simple measure is to reduce the number of worms released during fishing practices. Even in regions that already have worms, releasing more increases the number of available mates for the worms, assisting their proliferation and migration efforts. The Minnesota Department of Natural Resources, in cooperation with local groups, has launched a public education campaign using posters in bait shops and other outreach efforts.

The movement of dirt from one location to the other could also be regulated so that dirt from areas where earthworms are common is not moved into forests without the invasive species. ##To prevent the spread of invasive earthworms, it is recommended that people should only purchase compost or mulch that has been heated to appropriate temperatures and duration following protocols that reduce pathogens and kill the earthworm cocoons, or eggs.[4]

In areas that have already been colonized, the number of worms can be reduced by removal of introduced shrubs such as common buckthorn (Rhamnus cathartica) and honeysuckle (e.g., Lonicera x bella), which produce leaf litter favored by worms. This may help mitigate negative impacts on the ecosystem.

#Mustard pours can be used to survey for invasive worms at a site. A mustard pour can be created by mixing a gallon of water with one third cup of ground yellow mustard seed. Pouring the solution slowly over the soil will drive worms to the soil's surface without harming the plants.[5] People with invasive worms on their property are advised not to move plants or soil from their property.

  1. ^ a b Chang, Chih-Han; Snyder, Bruce A.; Szlavecz, Katalin (2016-10-31). "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): 495–529. ISSN 1175-5334. PMID 27811684.
  2. ^ Greiner, Holly G.; Kashian, Donna R.; Tiegs, Scott D. (2012-10-01). "Impacts of invasive Asian (Amynthas hilgendorfi) and European (Lumbricus rubellus) earthworms in a North American temperate deciduous forest". Biological Invasions. 14 (10): 2017–2027. doi:10.1007/s10530-012-0208-y. ISSN 1387-3547.
  3. ^ Zhang, Weixin; Hendrix, Paul F.; Snyder, Bruce A.; Molina, Marirosa; Li, Jianxiong; Rao, Xingquan; Siemann, Evan; Fu, Shenglei (2010-07-01). "Dietary flexibility aids Asian earthworm invasion in North American forests". Ecology. 91 (7): 2070–2079. doi:10.1890/09-0979.1. ISSN 1939-9170.
  4. ^ F., Hendrix, Paul; J., Bohlen, Patrick (2002-09-01). "Exotic Earthworm Invasions in North America: Ecological and Policy ImplicationsExpanding global commerce may be increasing the likelihood of exotic earthworm invasions, which could have negative implications for soil processes, other animal and plant species, and importation of certain pathogens". BioScience. 52 (9). doi:10.1641/0006-3568(2002)052[0801:EEIINA]2.0.CO;2. ISSN 0006-3568.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  5. ^ "Great Lakes Worm Watch :: Methods". nrri.d.umn.edu. Retrieved 2017-10-31.