Controlling Earwigs, Sowbug, Snails, and Slugs

Do you wake up to holes chewed out of leaves and edges of leaves nibbled on? Maybe entire seedlings disappear in the night. There are pests that under the cover of darkness target your garden and then seek cool, dark places during the warm days to hide. Their damage is often blamed on caterpillars.   These sneaky garden pests come from diverse families including mollusks, crustaceans, as well as insects. They include earwigs, sow bugs (pill bugs), slugs, and snails. 

Earwigs

These are for me, the creepiest of insects.  They are easily recognized by their formidable rear pincers.   The pincers are used to hold prey, ward off attacking ants, and to reproduce. Although physically harmless to humans their appearance can  be haunting.

Recognizing Earwig Damage

Earwigs feed on the foliage, flowers, and fruits of plants in the garden, orchard, and berry patch making them a nuisance to gardeners. They also feed on decaying plant matter.  On a positive note, they will feed on aphids and mites, but not enough to be recognized as a beneficial insect.  Leaves attacked by earwigs will have ragged holes in the leaves and the margins of the leaves will be chewed.  Earwigs bore into maturing fruit and eat the flesh.  Earwig damage is similar to catipillar damage so you must look for them at night.

Plants Earwigs Attack

Although they will feed on a host of leaves, flowers, and fruits, some of their favorites are artichokes, bean seedlings, corn silk, lettuce, potatoes, roses, and stone fruits (apricots and peaches) strawberries and zinnias.

Live Biological Controls

Assassin bugs, praying mantis, and tachinid flies all prey on earwigs.  

Cultural Controls

•  Keep the garden free of debris
• Trap earwigs in pie pans or tuna cans set into the soil so the rim is even with the soil surface and bait with tuna juice mixed with water and a couple drops of dish soap.  Check the traps and dispose of the earwigs frequently. 
• Sections of hose, hollow bamboo, corrugated cardboard, or rolled up newspaper will serve as hiding places and can be laid in the garden beds and emptied in the morning

Organic controls

• First choice is iron phosphate products which are sprinkled in the garden beds.  Common names include Sluggo Plus and Slug Bait.  Iron phosphate is a mineral common in soils and safely used in organic gardening. 
• Diatamacous earth may deter earwigs outside in garden paths. 

Sow Bug, Pill Bugs, or Rollipollies

My grandchildren love these fascinating crustaceans with jointed armor that roll into a ball when picked up.  Grandma, on the other hand,  is tried of them munching on my strawberries.

Recognizing Sowbug Damage

Because they are related to crayfish, sowbugs need moist cool environment. Established plants are safe from pillbug   Seedlings such as beans, can be severely damaged.  Strawberries are a favorite.  The picture above shows the damage.

Cultural Controls

Sprinkle Diatomaceous earth around house foundation or around garden beds.  Since it must be reapplied when wet I don't use it in the beds. 

Organic Controls 

• Place a potatoes cut in half with the cut side down inside  around the beds.  In the morning brush the pillbugs off the potatoes into the garbage.
• Yellow or blue sticky traps placed on the ground 
• The best solution is to use iron phosphate products which are sprinkled in the garden beds.  Common names include Sluggo Plus and Slug Bait.  Iron phosphate is a mineral common in soils and safely used in organic gardening.

Slugs and Snails

Slugs and snails, members of the mollusk family, have been enjoying gardens world wide.  Both are similar, but slugs lack a shell.  They excrete a slimy coating to prevent their bodies from drying out and to make travel easier.  Sometimes you can see a slime trail left behind.

Both slugs and snails are hermaphroditic which means each snail and slug has both male and female reproductive organs.  They lay hundreds of eggs a year.  In winter or dry spells, they go dormant.

Recognizing Slug & Snail Damage

• Slugs and snail can devour entire seedlings overnight.  
• They leave irregular holes in leaves and along the margin of leaves.  

Plants Slugs & Snails Feed On

• Young seedlings
• Mature annuals and perennials
• Tender vegetables like lettuce, strawberries, tomatoes, and peppers

Biological Controls

• Ducks, geese, moles, and garter snakes will eat slugs and snails; however, ducks, geese, and moles will do significant damage to your garden.  And snakes may not be a welcome guest.
• Frogs, toads, and salamanders are very fond of slugs and snails and can be encouraged to make your garden their home.

Cultural Controls

• Clear your garden of debris which serves as a hiding place and decaying plant matter serves as food.
• Water in the morning so foliage is dry in the night
• Place saucers of beer in the garden
• Hand pick and place in soapy water

Organic Controls

• Protect seedling by laying small flat circles of window screen around their base.  The rough surfaces are disliked by these pests
• Copper strips placed around plants.  Their slime reacts with the cooper.
• Iron phosphate sprinkled around garden beds and in planters

Info on Organic Products

Diatomaceous Earth:  this product is made from the crushed exoskeletons of microscopic sea creatures.  It is a fine powder that is irritating if inhaled.  It works by lacerating the bodies of pests causing them to dry out.  It controls slugs, snails, earwigs, ticks, fleas, and some ants.  It can be applies on the plant leaves or around  the base, but needs to reapplied when wet.  

Iron Phosphate: Iron Phosphate is a safer alternative to older slug and snail products that contain metaldehyde or methiocarb.  It is a mineral found in the soil.  Baits or granules can be used in garden beds.  The pests consume the bait and die within a few days.  It is effective on cutworms, earwigs, silverfish, pillbugs, slugs and snails.