While Harlequin bugs are bright and beautiful in color (often seen in red or orange and deep blue or black), do not be mistaken. These hard-shelled bugs can cause damage to crops of vegetables such as cabbage, cauliflower, beets, and fruit trees, just to name a few.
Harlequin bugs (Murgantia histrionica) are destroyers of crops in the southeastern portion of the United States by, literally, sucking the fluids from plant tissue. Unfortunately, the bug has been seen recently as far north as New England and as far west as California.
Having an intentional plan to control or get rid of them from your vegetable garden is the only way to prevent the loss of crops due to damages.
How to Get Rid of Harlequin Bugs Naturally
The following are natural ways to prevent and/or remove Harlequin bugs from their favorite crops such as broccoli, mustard greens, collard greens, kale, cabbage, and cauliflower. Keep in mind that these bugs have three life stages: Egg, Nymph (no wings), and Adult (similar to Stink Bugs).
The home remedies and natural solutions may kill only one, two, or all life stages. Therefore, be mindful that your plan may need to include a few options below to rid or prevent an infestation.
1. Pick Them Off
As the weather warms up, be ready to inspect and pick off leaves or stems as needed. Harlequin beetle eggs are barrel-shaped pods that are white with black bands.
Therefore, immediately remove the leaves on which you see them attached and inspect the rest of the plant. For nymphs and adult bugs, simply look for a bright display of insects that travel on stems and leaves.
Place the eggs, nymphs, or bugs in soapy water to suffocate and kill them.
2. Remove Weeds
The adult Harlequin bug can survive winter/colder seasons by burrowing in thick growth areas such as weeds or unwanted plants.
Therefore, inspect all areas and remove eggs and bugs as you find them. Additionally, remove any wilting leaves and get rid of weeds from your garden.
3. Trap Crops
One strategy to isolate the population of the critters is to plant their favorite crop(s) in one area, either around the edge of the garden or in a completely different area.
Or, you can plant a separate area first before other crops in order to focus the bugs in one area. Traps crops include such as kale, broccoli, or mustard.
4. Guinea Fowls
These bugs are a delicious snack for guinea fowls. So having a few around your yard is an easy and effective harlequin bug organic control method. And, fortunately, guineas do not scratch and destroy the earth (or garden) as chickens do.
5. Row Covers
Hanging garden screen barrier netting is a good alternative to keeping bugs off plants.
Simply hang such netting from a hanging PVC pipe, clothesline, or other types of wire to create a shield around plants without sacrificing sunlight. Alternatively, purchase ready-made row covers from local gardening centers.
Utilizing traps to attract then kill these bugs can be another component to control harlequin bugs. Testing has been done that has determined these bugs’ favorite colors are green, black, and red.
These studies also showed that a trap set out for 7 weeks and placed off the ground a bit can catch hundreds of harlequin beetles.
One way to trap them is by filling a green bucket with soapy water and allowing them to plunge into the water and die.
Another harlequin bug trap is the Dead Inn Stink Bug trap. Place it outdoors to lure and catch the pests.
7. Harlequin Bug Predators
Unfortunately, due to the stinky nature of this bug, it rarely has insect predators (beneficial insects).
Therefore, no ladybugs or other common helpful insects placed in your garden can rid the population of these bugs. However, other natural predators such as birds and toads will eat harlequin bugs.
8. Diatomaceous Earth
Using this powdery substance is an effective way to control harlequin bugs organically. These critters have a very hard and protective exoskeleton. However, by removing this exoskeleton, the bug will die.
This method destroys its exoskeleton which will cause the bug to dehydrate and die. Diatomaceous earth will kill the pests at both the nymph and adult stages.
9. Neem Oil
An effective solution to deter harlequin bugs, neem oil is a safe and natural pest repellent.
However, be sure to spray the entire plant, including the areas bunched up where the bugs could be seeking shelter from the cold.
10. Companion Plants
Good news! These bugs despise the smell of some plants like garlic, mint, tansy, and catnip. Therefore, sporadically planting these plants that repel harlequin bugs throughout the garden will help prevent an infestation.
11. Kaolin Clay
By creating a barrier on the plant, you can repel the bugs with this natural mineral because it causes confusion and irritation. Kaolin clay is an effective crop protectant that you can dilute in water and spray directly on plants.
12. Insecticidal Soap
Another solution that works at all life stages is insecticidal soap. Insecticidal soap spray kills harlequin bugs.
13. Crop Rotation
Rotating crops is a good way to get rid of bugs and pests. By completely uprooting, removing, and destroying the previous crop, any infestation or damage can be thrown away.
In addition, by preparing new soil and tending the ground for a new crop, any bugs that have been trying to stay warm during the winter temperatures will be exposed.
However, be sure to discard all material. Do not put them into a compost pile or recycle them in any way.
Harlequin bugs are strong pests in the world of crops. The females can live up to 82 days and they reproduce rapidly. One season of crops can easily see hundreds of these pests.
By knowing what they are attracted to or by what prevents them from living, crop owners can formulate a multi-tiered plan to either prevent an infestation or rid crops of this destructive bug.