We have “green spotted ladybugs” in our garden eating leaves and flowers. This is what I first thought when we lived in Marin County (north of San Francisco) and I’d see a few of these a year. But now, living along the central coast, I have hundreds of these pests invading my garden each year, starting in about June! They are not “ladybugs”! They are not beneficial insects. They are BAD BUGS known as the Western Spotted Cucumber Beetle or Diabrotica undecimpunctata. They feed on crops and flowers. They have no predators. Some say that birds eat them but chickens avoid them. They must not be tasty and delicious because my hens will normally eat most everything!
The spotted cucumber beetle is out in force this year due to the mild winter. They feed on leaves and blossoms and lay their eggs in the soil below. The larva look like tiny green worms. If the winter cold doesn’t kill them, they hatch and fly or crawl to the branches above. They can go through several of these cycles each year.
When my two granddaughters were visiting this month I put them to work in the garden. Ages 4 and 7, they like to earn money for doing chores. I offered them a penny for each cucumber beetle they killed. Within 30 minutes I was out a dollar and they had drowned a hundred of the little pests. They repeated the labor the next day and would have every day of their visit if it weren’t for child labor laws and had they not gone off to the Monterey Aquarium and the Forth of July parade in Cayucos to spend their money. Lots of fun-filled days and my cucumber beetles were much diminished!
Now I can’t tell you how to rid your garden entirely of these beetles, but I can tell you how to reduce their numbers. Put soapy water into a small bowl. Wander the garden each morning for 10-15 minutes. The beetles are slow in the morning and will be less inclined to fly away when they see a “giant” hovering over them. Put the bowl beneath him if he tries to drop into the soil below. Knock the bug into the soapy water. He won’t suffer long and you’ll have one less beetle in your garden to deal with. Good luck central coast gardeners. This pest is the price we pay to live in such a beautiful, mild, climate. For more information on decreasing the numbers of cucumber beetles in your garden, see the article in this blog that I wrote in my frustration several years ago.
They’re not just out west! I just knocked them off my montauk daisies which were pretty yesterday & decimated today. I used to think they only ate cucumbers. . .
From Barb in Ohio
Thank you! I knew they weren’t beneficial but couldn’t find ANYWHERE exactly what kind of bug and what their larvae looks like. So, that being said, can I use an organic “pesticide” called Neem in the soil of our raised beds where I have found evidence of them on my lettuce? Both the bugs as well as their larvae? or spray the diluted neem on foliage or both soil and foliage or none of the above. I will do your above recommended but wonder if I can use the Neem as well.
Oh, these are the most frustrating of insects. Even my hens don’t like them. I wouldn’t recommend using neem oil on the soil or on foliage you are going to eat. Using it on the soil may destroy the microbes that live in the soil. I’ve read that keeping the mulch under the plants stirred up, exposes the larvae and reduces the numbers but I’d be careful with any pesticide, even natural ones, around food crops.
Apply predatory nematodes to the soil and it will kill them off.
I’ve been using home made pepper spray which seems to be very effective. Blend 2 garlic heads with four or five hot pepper s with water. Strain the bits out and put in a spray bottle
I’m going to try this. I’ll let you know if it works on my Dahlias.
I noticed thread little lime green like lady bugs in my back patio. I have a lot of planted flower and succulents. Also have a large tree in the yard. I just moved here in Dec. So I noticed the tree looking kind of sick, flooding a lot of leaves. Summer is upon us so knew that’s not right. So I had my yard and home spayed for bugs. That didn’t kill them. Can they be eating my tree? I’m in Chandler, Az
I’ve not heard of the cucumber beetle causing damage to trees. It is hard to spray for them because they fly from yard to yard very easily. If I were you I’d try to find out what is wrong with the tree. It might be thrips. Take a piece of it down to your Master Gardener’s office (usually in your county’s farm advisors office) and have it looked at. They can advise you.
Spraying kills all the good bugs as well as the bad bugs and too much spraying will cause your garden to get out of balance.
Lee did the garlic red pepper spray work? I have been picking a dozen or more of these bad guys every day off of my dahlias and roses for weeks, and now the Japanese anemones are being spoiled by them. But having a garden that smells like garlic is hardly exciting. Did you use it on the soil or on the plants?
i just found them on my dahlias… little monsters they are!!!!!!
Keep after them! Knock them into a bucket of soapy water in the morning before they fly about. Each day you’ll see less and less!