Flea beetles can be very destructive to a wide variety of plants, so be sure to take preventative measures.
Learn How to Prevent These Garden Pests!
How to Identify Flea Beetles on Plants
Given that there are so many species of flea beetles, they vary in appearance quite a bit. Colors range from black to tan, with other, brighter colors mixed in, and the beetles may have a solid, striped, or spotted pattern, depending on the species.
To identify flea beetles, it鈥檚 easier to look for signs of their damage (described below) than for the beetles themselves. At only 1/16 of an inch in length, flea beetles are very tiny and will quickly spring away鈥攍ike fleas鈥攊f they see you approach!
When Do Flea Beetles Appear?
Adult flea beetles overwinter in brush and wooded areas. Adult bugs pose the biggest threat early in the planting season as they are emerging, typically when outdoor temperatures reach 50潞F (10掳C). At this time, seedlings are being planted, too, and they are most susceptible to beetle damage.
Eggs are laid at the base of plant stems in early summer after the spring feeding period, and larvae feed at the roots.
What Flea Beetle Damage Looks Like
Adult beetles feed on foliage, producing 鈥渟hotholes鈥 in the leaves. Look out for these holes, especially on young seedlings, where damage is most rapid and will cause the most harm. The holes they make will be round and can quickly ruin leafy greens. New leaves are usually damaged first and will have a lacy appearance.
Flea beetles usually don鈥檛 cause fatal damage to established plants because the leaves are already large enough to survive a few holes. The real danger is that the beetles can spread bacterial diseases, such as wilt and blight, from plant to plant. Additionally, in leafy crops like lettuce or spinach, the holes can bring down the quality of the leaves. Therefore, they are still important to consider as pests.
Catherine Boeckmann
ADVERTISEMENT
hi, We have some mustard grown here, unfortunately, flea beetle left so many holes on them. After that, I found that the hole edge get purple, so it looks like there are so many purple holes on mustard. It's different from holes flea beetle left on other vegetables. Do you know the reason for this?
Flea Beetles are destroying my black eye Susan鈥檚, echinacea, and daises. They are eating the petals before they emerge. I tried the spray recommended on this web site but not great. Any other suggestions?
I've heard that dusting the plants in talcum powder will help, but my in-laws recommend spraying a mixture of water, vinegar and dish soap on the leaves and stems to repel all insects
Some varieties of mustard naturally have a purplish tinge to the leaves, so our guess would be that the tissue immediately surrounding the holes in the leaves starts to die and lose its green chlorophyll, leaving the dark color around the holes. On the other hand, a fungal disease called alternaria leaf spot may cause purplish-black lesions in leaves. Search google for an image of alternaria leaf spot and see if it matches what you’re seeing. If alternaria leaf spot is the culprit, remove heavily affected leaves and avoid planting mustard in the same spot next year.
I am just wondering whether the dead beetles sprayed with this mixture pose any danger to songbirds foraging in the garden?
Hi Kathleen,
The amount on the insects should be small enough that there will be no adverse effects to birds.
Can I make a spray with 100% alcohol? Maybe only 1shot to 5cups water?? Or would coffee grounds be better on the ground with flour sprinkled on the plants?
How often should you use the spray?
Hi, Meredith. You can apply as often as once a week. Good luck!
Do you have any suggestions for eradicating flea beetle indoors? I am a florist who uses locally grown flowers and these bugs seem to have setup camp in the drop ceiling of my studio. Not sure what they are surviving on.
