Location: Alaska
Description: Slugs are a growing problem particularly in coastal communities where temperate rainforests or wet conditions provide an ideal environment for some invasive species.The purpose of this project is to document observations of slugs to better understand their range and impact and to share information about safe and effective control measures. This project is a contributing data source to the Cooperative Agriculture Pest Survey Program (CAPS).
Land Slugs: Land slugs are shell-less mollusks in the class 'gastropods'. They like wet environments and are vulnerable to drying so they protect themselves by secreting a protective mucus slime.This mucus has many benefits - it helps them climb, the slime trail can be used to find a mate, or by the carnivorous varieties, to track down prey. It also provides protection from predators as it sticky and can have a bad taste. Slugs are hermaphrodites having both female and male reproductive organs. These lay their eggs in moist places underground.They feed on a wide variety of materials including leaves from living plants, lichens, mushrooms and other slugs and snails, or earthworms.
Invasives Slugs: There are several species of slugs that are either exotic and invading Alaska or native and expanding their range into new areas. Most of these have been identified in Southeast and Southcentral Alaska, but they may also have spread to other areas. Most are considered pests and a particular concern for agriculture. Others are emerging as a concern because they have significant impacts on natural environment and native species.
Slugs and Human Health: The impacts of slugs as garden pests are well known.They can interfere with the production of healthy foods, and the control methods (such as pesticides) carry their own health risks. But slugs can also carry diseases that affect people. Consumers of unwashed garden vegetables have likely experienced the distasteful surprise of a slug. Washing garden vegetables is important as some slugs carry diseases that can have serious health effects for people. One example not found in Alaska, but expanding in other areas of the country is called 'Rat Lungworm" Slugs are an intermediate host for a parasitic worm that causes rat lungworm disease, an illness that causes brain disease in humans. The worm, Angiostrongylus cantonensis, is endemic in the United States. People are infected by eating the carrier slugs or their slime. Rat Lungworm is spreading and has been identified in Florida and California among other southern states. In Hawaii, health officials are warning people not to handle backyard slugs or snails with bare hands. The species of slug that carries rat lungworm, Parmarion martensi has NOT been identified in Alaska.
European Black Slug (Ader Rufus Vulgaris Complex) These are exotic invasive species which can either appear as black or brownish. They have been identified in Alaska as early as early as 2005 in Cordova, Soldotna and Fairbanks. The have been documented now in (CAPS) program in Ketchikan, Wrangell, Sitka, Gustavus, Cordova. News reports place the slugs in Whittier in 2016.
European Red Slug (Arion rufus)
Giant Garden Slug (Limax maximus) These are an exotic invasive species that have been documented by CAPS in Wrangell.
Banana Slug (Ariolimax spp.) - These are native slugs in two different varieties which have been documented by CAPS in Sitka Ketchikan, Wrangell, Juneau and Sitka. Apparently they are edible, and by some accounts (if prepared properly) quite tasty, although with a flavor not to be compared with bananas.. See: Feral Foods article: How to Eat Slugs. There are many other recipes on the internet, but cooking thoroughly would be advised to prevent any risk from parasites.
Taildropper Slug (Prophysaon sp.) These are a native species which have been recorded by CAPS in Haines, Skagway, Juneau, Ketchikan and Wrangell.
Grey Garden Slug (Deroceras reticulatum) These are an exotic from Europe that have been documented by CAPS in Ketchikan, Sitka and Wrangell.LEO Network has document these in Sand Point since 2013.
Brown-banded Arion (Arion circumscriptus) This is an exotic species that heen documented by CAPS in Sitka.
Dusky Slug (Arion subfuscus) This is an exotic species that has been documented by CAPS in Kodiak, Haines, Juneau, Ketchikan, Sitka, Wrangell, Valdez and Girdwood.
Observing Guidance: Please collect information on the time and location of the observation, and insights on impacts or changes in slug populations, time when slugs were first observed in your area (if known) and detail photos of the slugs and vegetation they are consuming.Jacqueline Schade writes: "If people would be willing to collect slug or snail specimens, I can add them to the CAPS survey. This would at least give us an idea if they are nationally invasive slugs and snails. I can provide specimen collection supplies and instructions on how to collect and ship the specimens for those that are interested."
Sample Collection:
To preserve/submit slug and snail samples:
Put the slug or snail in a vial, fill the vial with water (preferably distilled, but tap water will do just fine), get out as many air bubbles as possible and put the lid on. Leave the slug/snail in the vial until drowned (12-24 hours). The slug/snail will just float around in the jar once it has died.
Once dead, preserve the slug in a vial with 70% ethyl alcohol. If you do not have access to ethyl alcohol, one option would be to send the slug to me in water. For this, you would need to place the slug in the mail ASAP after collecting the sample.
One slug or snail per vial.
To submit the sample for this survey, mail sample to: 1800 Glenn Hwy, Ste 12 / Palmer, AK 99645
Cooperative Agricultural Pest Survey (CAPS) Program in Alaska (.pdf) - Jacquelyn Schade, SSC - Alaska Department of Natural Resources
Source Data: LEO Network observations.
Outputs: What kinds of information outputs should contributors expect from the project? Example: addition to regional map, addition to timeline trend. Development or inclusion as contributor to published report or paper.
Project Updates:
July 29, 2017 - Jacquelyn Schade writes: The Cooperative Agriculture Pest Survey Program (CAPS) is performing a mollusk survey this year and next year. A colleague and I will be surveying the Fairbanks, Anchorage, and Mat-Su areas this year and will survey the Kenai Peninsula and Kodiak areas next year. Currently there are no management efforts in place to control the black slugs in Cordova. However, the Forest Service is currently in the process of creating an Invasive Slug Action Plan for the Chugach National Forest. The Invasive Slug Action Plan was begun in response to the black slugs invading the Cordova and surrounding areas. Currently there are no management efforts in place to control the black slugs in Cordova. However, the Forest Service is currently in the process of creating an Invasive Slug Action Plan for the Chugach National Forest. The Invasive Slug Action Plan was begun in response to the black slugs invading the Cordova and surrounding areas.
July 31, 2017 - Ivy Patton writes: " I have seen black slugs on the islands throughout Prince William Sound, including the villages of Chenega Bay and Tatitlek. I’m constantly surprised to see how far their territory has expanded, you could see them high on Mt. Eyak and Crater Lake trails. It is my understanding that a few arrived in the 80’s in boxes of produce and about 5 years ago had a population explosion. My research has shown that these critters are hard to kill. They stay alive on tires after they have been run over and that’s how they get out the road. I grew up in Cordova until 1989 and do not remember them from my childhood. I moved back in 2010 and noticed them immediately! "
Resources:
Cooperative Agricultural Pest Survey (CAPS) – What is CAPS? To confirm the presence or absence of plant pests, provide a distribution profile of plant pests in the U.S., and early detection & rapid response to exotic pest infestations. Source: Alaska Department of natural Resources
See presentation by State Plant Health Director Ann Ferguson - Cooperative Agricultural Pest Survey
(CAPS) PROGRAM IN ALASKA. This is a product of the Animal & Plant Health Inspection Service (APHIS)
Alaska Department of Fish & Game (ADF&G) – Invasive slugs are documented in the Non-Native and Invasive Animals of Alaska Report by the ADF&G as being a non-native species.
ADF&G has provided guidelines for invasive species control and prevention. These include inspecting everything that could be a "carrier of insects, plant seeds or fragments, whole or pieces of animals that can reproduce asexually, and even pathogens. Inspect and thoroughly clean whatever has come into contact with the infected landscape or waterway: shoes, clothing, pet fur, fishing boots and gear, and vessels or vehicles of any kind. For example, be sure to thoroughly clean the tires and undercarriage of cars, trucks, all-terrain vehicles, and cargo vehicles, as well as boat hulls, holding tanks, ballast tanks, anchors, and lines." Source: Alaska Department of Fish and Game, Invasive Species Prevention.
USDA Publication: Climate Change Vulnerability Assessment for the Chugach National Forest and the Kenai Peninsula
Observations From Members