I don’t suppose it would help much to describe these gross little pests :-). Here it is anyway…..slugs are long snakelike mollusks that have a slimy coating.Â
Slug-General Exterminators Inc. (left), Slug-Maine Pest Management Lab (right)
They come in many different sizes and colours, black, brown, tan, greenish, spotted and creamy. They range in size depending on where they are found. The pacific northwest see slugs that are enormous…..especially ones found in the forest. There are thousands of species!
slug-University of Nebraska (left), Eggs- Ohio State University (right)
Habitat and Lifecycle
They occur in most in most parts of the world and are more abundant in cooler, damper climates. (I never thought I’d see one in Texas but lo and behold they are here). Females & males lay up to 80 roundish pearly white eggs in the soil. (one species that exchanges semen) Adults take only a year to mature and they can lay eggs several times a year. Coastal areas have slug damage year round whereas hotter climates or where winters are cold they hibernate in the soil. Slugs are mostly nocturnal and do most of their damage at night. Their size is between 3 and 13cm when full grown.
Slugs mating……censor your children!-copyrights 1997 Dr. Zeus
Diet and Damage
They feed on everything and can also be seen in the compost eating decaying matter. They will eat irregular holes in leaves and flowers. Evidence that slugs are present is the slimy trail they leave behind. Here is a list of plants that slugs do not usually bother but remember if they are hungry…..they’ll eat this too.
Plants that Resist Slug Damage
Ageratum, Allysum, Begonia, Cosmos, Geranium, Lobelia, Nasturtium, Nemesia, Portulaca, Painted daisy (Pyrethrum), Verbena, Zinnia
1) Hand Pick
At dusk slugs emerge to do their damage. Track them with a flashlight and drop them in hot soapy water. Salt will also kill them but be careful with this as it is not always good for the soil. Try to use salt only on your deck or sidewalks.
There are several traps you can use:
Soggy newspaper laid on the ground in the evenings. In the morning you can burn this or drop them in soapy water.
Beer in small cups, slugs are attracted by the yeast but I’m not sure if it attracts them or just kills them because they are there. You may want to add extra yeast to the traps. Clean them out daily.
Copper barrier tape applied to pieces of wood or other material will stop them from crossing to susceptible plants like lettuce. Apparently it creates a small shock. I saved my little green strawberry baskets and tipped them upside down on my tender lettuce seedlings and I had no slugs cross through.
Decollate Snail-University of California, Jack Kelly Clark
3) Natural Predators
Snakes, toads, frogs, birds, some beetles, and decollate snails (shown above)
4) Diatomous Earth, Coarse Sand or Ashes
You can sprinkle DE around susceptible plants and they will not cross it as it cuts up their tender bodies. Be careful with this as it will also kill your worms. Ashes as long as it is from untreated wood and has no additives. If you use sand be sure it has been well washed so that you do not add any unwanted chemicals or salt residue to your soil.
5) Egg Shells or Oyster Shells
Crushed egg shells or oyster shells sprinkled around your garden is a preventative measure. Slugs will not cross anything that is sharp.
Try to avoid watering after 1pm as slugs like the moist soil conditions. If you must water in the evenings then be sure to patrol the areas and hand pick.