Q1: I have read about the spread of vermiculture worms sold for composting into natural areas in the US as a result of being released (with disastrous results). Are these the same species?
A1: I’ve personally never heard of jumping worms being used for vermiculture, so my suspicion is that these would be different species. Most vermicomposting is done with non-native “red wigglers” (Eisenia fetida/Eisenia Andrei), which tend to do poorly in natural areas in Canada.

 

Q2: How familiar are nurseries with these worms? Given we are coming into spring are nurseries doing anything to prevent bringing more into Ontario?”
A2: This is an important question because of the key role that nurseries (unintentionally) play in dispersing jumping worms. Given that this is a recent arrival, I would guess that most are unaware, though they may have heard about the situation in the US. I’m not as familiar with
the regulatory/policy angle, but so far as I know, there are no real restrictions that would effectively screen out jumping worms or their cocoons.

 

Q3: What are the ecological impacts (of the jumping worm)? You indicate it is dramatic but it would be helpful to know the specific impacts.
A3: Most of the large ecological impacts of jumping worms come from their ability to rapidly break down organic matter that would otherwise accumulate at the soil surface. This transforms the upper horizons of the soil profile, reducing or removing the physical protective layer of leaf litter to expose the soil below. This reduces the habitat available to many soil organisms, can leave seeds and seedlings more vulnerable to desiccation and herbivory, and can contribute to soil erosion. In addition, jumping worms accelerate the cycling of nutrients from decomposing organic matter (which can facilitate plant invasion or lead to a loss of nutrients from the soil) and may reduce the ability of the soils to store carbon. Many of these impacts are similar to those of non-native European earthworms, but they tend to be faster and greater due to the high biomass and density of jumping worm populations.

 

Q4: There is no way to stop the movement of plants from infected areas, thanks again to the landscaping industry! Many, many of the plants in nurseries in Eastern Ontario come from the infested areas! Is anything being done to try and address this?”
A4: There are currently frustratingly few policy restrictions that would effectively limit the spread of jumping worms or their cocoons. I suspect that this is due to a perceived absence of direct, immediate economic impacts (though it is important to note that the complex ecosystem engineering impacts of non-native earthworms almost certainly have and will continue to have economic impacts in gardens, forests, etc., resulting from loss of biodiversity and ecological function). At this point, I would suggest being vocal about this and other invasive species issues with local government representatives and stakeholders within the horticultural industry to raise concerns about this issue.

 

Q5: Have you considered trying to educate the growers in Western, Ontario, as well the plant nurseries? Would it make sense to remove all the soil from those potted plants and sterilize it?
A5: We’ve just started trying to get the word out about this now that we know they are here. Anyone who is able to help spread the word can be of assistance in this. While we do want to reduce the extent and rate of spread where possible, it is also important to accept that there is a certain inevitability to this. Like with non-native European earthworms, we can’t completely stop the influx of jumping worms, nor can we remove all that are already here. Therefore, I would not advocate any form of extreme sterilization approach. Instead, I think we should adopt best practices to minimize the spread such as proper heat treatment of soils and composts, visual screening for jumping worm activity, etc., where possible.

 

Q6: Should we worry about using professional Pro Mix?
A6: I haven’t yet heard any reports about jumping worms nor their cocoons being found in Pro- Mix, but it can’t hurt to keep your eyes open!

 

Q7: How cold tolerant are the cocoons? Are the northern climates protected by the sub- zero winter temperatures?
A7: Jumping worm cocoons can dehydrate to tolerate sub-zero temperatures as low as -24 °C. However, they also require a sufficiently long warm growing period over 5-10 °C to hatch, mature, and reproduce. Therefore, northern climates do offer some control against jumping worm invasion, though this protection will likely continue to wane with ongoing climate change.

Q8. “Has there been any invasive worm control methods that have been attempted in North America and have failed (pesticide, predator introduction, etc.) on a large-scale? And have there been any successful control methods on a “small-scale”?
A8: To the best of my knowledge, there have been no large-scale attempts at control. Many smaller-scale experiments have been conducted using vermicides, controlled burns, etc., but none have been sufficiently effective, target-specific, nor cost-effective to be practical.

Q9: Are there any ‘bastions’ where native worms are present and dominant across Ontario or Canada?
A9: Because glaciation was responsible for the loss of most of our native North American earthworms, the few remaining species tend to primarily be found in refugia that were less affected by glaciation. The highest concentration of these species can be found in British Columbia, though even there, native earthworms have quite limited distributions.

Q10: Is there any chance that wildlife can move jumping worms, ex: birds?
A10: My guess is yes. I’m not sure how much research has been done on this, but birds in particular may facilitate the dispersal of earthworms either by dropping a would-be meal during flight or distributing cocoons in clumps of soil.