Japanese Beetles, Squash Bugs, and More
Become a better gardener! Discover our new Almanac Garden Planner features for 2024. It’s easy, fun, and free to try!
When gardeners aren’t talking about the weather they are talking about bugs. This year in my garden there seems not to be so much damage from slugs and cutworms as there is from beetles.
This should not come as a surprise since beetles are the most common insect in my neck of the woods.
Most beetles are good bugs; they eat other insects and are an important link in the food chain for snakes, lizards, birds, and small mammals. Don’t kill every beetle! The average backyard is home to thousands of insects and only a fraction of them are destructive, most are either harmless or beneficial. Learn more about the many beneficial insects in the garden.
Read Next
Keeping Beetles at Bay
The most common methods of bug control for organic gardeners are barriers, traps, repellents, and handpicking. Knocking the beetles into a pail of soapy water works well. A friend of mine devised a handy bug collector made from 2 plastic milk jugs. He taped the two together at the necks and cut the bottom out of one to make it into a giant funnel. Add a little soapy water in the bottom jug and head out to the garden.
Japanese Beetles
This milk jug method works especially well for Japanese beetles since they tend to fall straight down when disturbed. Go out in the morning when the bugs are still sleepy. Place the funnel underneath the clusters of beetles and brush them in. See more about Japanese Beetle control.
Lily-Leaf Beetles
Beetlemania started early this year with the lily-leaf beetles. We now know to look for them as soon as the Oriental and Asiatic lilies (thankfully they don’t bother daylilies) start to emerge. These bugs require constant vigilience on our part or they quickly get ahead of us and decimate the lilies. Bright red with black legs, at least they are easy to spot. They lay eggs on the undersides of the leaves and their larvae do as much damage as the adults, eating huge amounts of foliage each day. The larvae have the disgusting habit of covering themselves with their excrement to avoid detection so it is important to squish the poop piles as well as the beetles to stay ahead of future generations.
Striped Cucumber Beetle
The striped cucumber beetle attacked the squash plants first but soon found the cucumbers and established a colony there as well. They are pollen eaters so they are attracted to the bright yellow squash blossoms and cucumber flowers. I have used yellow sticky cards to trap them in the past but found that I was catching beneficial insects too, so I had to stop.
Young plants can be covered with well-anchored row covers in the spring which helps to thwart the beetles early on, but the covers need to be removed when the plants begin to blossom to allow other insects in to pollinate them. It is important to get rid of as many cucumber beetles as possible because they not only eat pollen, flowers, and leaves but also infect the plants with a bacterial wilt that can stunt or kill the whole plant. Their larvae feed below ground on the roots and underground stems and they can spread wilt also. Once a plant has wilt there is no cure. It is best to pull it out and remove it from your yard. Watermelons and some winter squashes such as acorn, blue hubbard, and butternut are resistant to this wilt.
See more about Cucumber Beetle control.
Squash Bugs Kill Plants
Squash bugs suck sap from the leaves and stems of squash and pumpkins and will damage the fruit if given the chance. They also transmit a toxin in their salvia that can kill young plants. Around the time the vines begin to lengthen, squash bugs start laying shiny, golden brown eggs on the undersides of the leaves.
The adults and immature squash bugs (called nymphs) hide under mulch near the base of the plants. One way to trap them is to place boards near the squash plants. At night, many of the bugs will congregate underneath them and in the morning you can give the boards a good stomp to crush them. Another remedy I have not tried is to make a tea from cedar chips soaked in warm water. Spray it on the plants foliage and on any squash bugs you see. It is supposed to kill them.
See more about Squash Bug control.
What’s Bugging You?
The list of beetles goes on and on. Colorado potato beetles, Mexican bean beetles, Japanese beetles, rose chafers, etc. Let us know if you have any home remedies for keeping beetlemania at bay in your garden. See our full garden pest and disease library.
Robin Sweetser
ADVERTISEMENT
Anyone have real time experience? I hear it's really effective.
I usually collect Japanes beetles in a wide-mouth jam jar, but the larger milk bottle sounds better.
I rarely have an adult squash bug in the garden because I check the leaves once a week (it takes a few days longer than that for them to hatch) and cut the little piece where the eggs are out of the leaf and throw it in the trash.
As for cucumber beetles, I have a wonderful new way to catch them. I happen to have a jar of Tanglefoot, which is sticky but otherwise inert, and I dip the big end of a flat wooden toothpick in it, reach into a squash or cucumber blossom, pick up the beetle (or couple), and drop it, stick and all, into a jar of soapy water.
Chopping bugs and larvae in half with small scissors sounds good, especially for bigger bugs that might be able to escape the Tanglefoot.
Is there some kind of master chart that has photos or drawings of all life stages for every kind of bug, both detrimental and beneficial? Or a good book that covers most of them?
I am familiar with some of the adults, but at a loss as to what eggs and larva go with what adult.
I, too, have the beetle/weevil problem. This year I have seen a larger population of Sri-Lanka Weevils--they seem to attack anything--Lime trees, Avocados, Okra, Eggplant. Fortunately, they have the same habit of falling straight down when disturbed--I use a peanut butter jar with ~ 1/2" of soapy water--easier to get in amongst the foliage. This works for stink bugs too--but they tend to fly away if you disturb them too much--I've been using a small pair of scissors to chop them in half--the scissors are small enough that they don't seem to see it coming(like a big hand with fingers)
Here in semi-arid climate, we have grasshopers, wasps and earwigs. They eat and make holes in everything. Especially the grasshoppers. No one seems to have a solution. Any organic ideas??
A petition is going around to the government to do something, but what can they do but spray all of us, our land and gardens with a chemical that could be bad for the dogs and cattle etc.
Grasshoppers are voracious eaters. There are several organic methods which might help to make a dent in your population.
Foster predators such as snakes, toads, cats, skunks, birds, chickens, ducks, Guinea hens, and praying mantids. They all are known to eat adult and juvenile grasshoppers.
Use barriers such as row covers or cones made from aluminum screening.
Try interplanting your crops with repellent plants. Grasshoppers don't like cilantro, horehound, or calendula.
Use repellent sprays made from garlic oil, hot peppers, strong coffee, or neem oil.
Make a grasshopper trap from 10 parts water to 1 part molasses in a half-buried jar. They will be attracted to the sweet molasses smell and drown in the water.
Dust plants with diatomaceous earth which has microscopic sharp edges that will slice and dice your grasshoppers.
Try the natural fungus Nosema locustae sold as Nolo bait or Semaspore. It weakens and eventually kills grasshopers that eat it and will eventually take a toll on the population.
Good Luck!
I have red beetles and something that looks like a tiny black slug in one section of my garden wall that attack everything I try to grow there. They really like my Asiatic lilies. They weaken and destroy everything I try to grow there. What massive effort can I use to get rid of them in that section. Love the smell of the lilies under the bedroom window and can't enjoy a single one.
That's the lily leaf beetle and the slug-like thing is its larvae. We grow several beds of Asiatic and Oriental lilies to sell to florists so they have to be pristine. We start patrolling for the beetles as soon as the lilies emerge from the soil in the spring and Tom checks them daily for new beetles and larvae, squishing as he goes. If you can't stomach the squish then drop them into soapy water. It might be too late for this year's flowers but start early next year to stay ahead of the infestation.
Any recommendations for keeping praying manthis at bay? Over-loaded with them. They destroy everything. They eat the good bugs and they are killing my garden.
I agree with Rose. I wish I had them too! Praying mantises are predatory and only eat other insects - good and bad they don't discriminate. I have never heard of them destroying plants.
