You’ll figure out if you have a chewing insects problem by being observant in your garden. Look high, look low, and leave no leaf unturned. Most insects don’t hide in plain sight. You might even have to look for them at night to catch them. Today we’re honing in on the signs and solutions for some common chewing insects.
Some of the main chewing insects we deal with in gardens are: caterpillars, cutworms/hornworms, slugs/snails, sow bugs (pill bugs), and flea beetles.
You usually can tell, just by looking, that chewing insects might be causing a problem. However, the damage can appear in many forms.
- Leaves can look ragged with holes in the center or around the edge.
- Foliage could be stripped and flowers may disappear.
- Leaves look “skeletonized”, or in the case of “borer” insects (like leaf miners) there are tunnel patterns on leaves.
- Plants may be “cut off” at the base of the plant, as though someone took an axe to it overnight.
Caterpillars, cutworms, and hornworms are chewing insects that love to chomp on the tender new growth of plants. Caterpillars can quickly ravage your food crops overnight, so at the first sign of caterpillars, take quick action. When I plant veggies, I check on them everyday. I go into battle mode when I see silken webbing on the underside of veggie leaves, tiny, pearlescent-eggs under the leaves, or the culprits trying their best to camouflage themselves against the leaves (they are good at it too). Look for caterpillar frass (black specks of poop) on the leaves of your plants too!
(Tomato Hornmworm, see how easily they blend in?)
- Manually remove and toss to the birds or into a bucket of soapy water.
- Spray with insecticidal soap. Must spray directly on caterpillars to be effective (this means spraying at night sometimes).
- Spray with BT (Bacillus thuringiensis), or Captain Jack’s Spinosad.
- Be sure to check under the leaves where they like to hide out.
(FYI: This blog is about unwanted chewing insects. If you’re worried about killing off a butterfly caterpillar (and this should concern all of us), you should learn what type of caterpillars you have in your garden. Click here to see some common caterpillars in Texas and what they’ll be at maturity. We always advise to start with the least toxic method of pest control first.)
Tender new growth on plants and rain tend to bring out snails and slugs like crazy. Expect these slimeballs to be chomping all night long, although you will also find them grazing during the day when the weather is drizzly and overcast.
- Baits: Products like Sluggo Plus, Bonide Bug & Slug Killer, contain granular baits that you can sprinkle around your plants. The baits attract snail and slugs and they are killed when they ingest them.
- Traps: Beer traps are a fairly cheap way to get rid of these insects. Pour a beer, fresh or stale, halfway up a 6-8 oz. plastic cup and place it on the ground by your plants. The little drunkards will climb in and not be able to get out. Change cups when they’ve been overloaded to keep the lure fresh.
- Diatomaceous Earth can also be used as an organic method for ridding yourself of the slithering duo. The product slices open the exoskeleton of insects when they crawl over it and causes them to dry out.
Sow Bug/ Pill Bug
Instead of an insect, Pill Bugs are actually classified as chewing crustaceans. Sounds like a horrible B-movie title doesn’t it? Coming soon to a garden near you….Attack of the Chewing Crustaceans! When theses insects attack your plants, like vegetables, it is usually because the leaves are directly on the soil. Mulching your plants could help to keep sow and pill bugs at bay.
- Sprinkle Sluggo Plus, Bonide Bug & Slug Killer around the base of your plants.
- Diatomaceous Earth can be applied around base of plants. Remember to reapply after rains.
The shiny, blue-black, or brown-black flea beetles are only the size of a pinhead. But you can be on the look out for small, round, irregular spots or holes on your leaves, in the pattern of a shotgun blast. Damage from flea beetles will cause your plants to take on a skeletonized, bleached out appearance before they wilt and die. Young, tender plants are most susceptible and they love to attack your veggies!
(Flea beetles come in many different species. Color variations apply.)
- Spray with Pyrethrin, Captain Jack’s Spinosad, or Neem oil.
- Garlic spray can be used as long as it is when you’ve caught the problem early, and it also must be applied frequently.
- Larger transplants when planting vegetables can also help to avoid the attack of Flea Beetles.
Always read labels of insecticides to provide correct application and to know if a follow up application is necessary.
With everyday observation, you will be able to protect your garden from the damage done by chewing insects. Early detection means less of a battle! Good luck!
~The Happy Gardener, Lisa Mulroy