Colorado potato beetles are a major pest of potato plants. These voracious insects can completely defoliate plants, leading to reduced yields. Organic methods can be very effective for controlling Colorado potato beetles without the use of synthetic pesticides. Here are the most effective organic methods for getting rid of Colorado potato beetles in your potato patch.
Identify Colorado Potato Beetles
The first step is learning how to identify Colorado potato beetles. This will allow you to detect an infestation early, before major damage occurs.
Colorado potato beetles are about 1/4 to 1/2 inch long with a rounded shell that can be cream to yellowish-orange in color. They have distinct black stripes along the margins of their wing covers. Their larvae are reddish-pink and soft-bodied, growing to about 1/3 inch long.
You may find the adult beetles as well as larvae on the undersides of potato leaves. The larvae are the most damaging stage, as they can quickly skeletonize leaves. Be sure to inspect the undersides of leaves to look for eggs, larvae, and adult beetles.
Handpick Beetles
One of the simplest organic control methods for Colorado potato beetles is handpicking. Check plants daily and handpick any beetles or larvae you find. Drop them into a container of soapy water to kill them.
Handpicking works best when an infestation first begins, before beetle populations build up. It’s most practical for small plantings. But even in larger plots, handpicking can control small infestations and slow down damage.
Use Row Covers
Row covers made from lightweight fabric can exclude adult Colorado potato beetles, preventing them from reaching plants to feed and lay eggs.
Install fabric row covers over plants immediately after seed potatoes are planted or transplants are set out. Bury the edges well or use weights to seal the row covers tightly to the ground. Be sure to leave them in place until plants start flowering, then remove to allow pollination.
This technique is especially useful for early season control. But removing covers for flowering allows some beetles to reach plants later in the season.
Apply Neem Oil
Pure neem oil extracted from the neem tree (Azadirachta indica) can deter feeding by Colorado potato beetles when applied to potato plants. Neem oil also reduces beetle reproduction and survival.
Use neem oil labeled for organic use, following label instructions. Lightly spray or drench leaves, stems, and the undersides of leaves where beetles are active.
For best effectiveness, start applying neem oil as soon as beetles appear. Repeat applications every 7 to 10 days for continuing pest deterrence. Neem oil is safe for pollinators and natural enemies when used as directed.
Use Kaolin Clay
Kaolin clay is a fine white mineral powder that can deter Colorado potato beetle feeding and egg laying when dusted on plants. The clay particles irritate the insects’ bodies and disrupt their feeding.
Apply kaolin clay labeled for organic use according to label directions. Use a dust applicator to lightly and evenly coat leaf surfaces, especially the undersides of leaves where beetles feed and lay eggs. Reapply after rain or overhead irrigation.
Target newly hatched larvae early in the season for best control. Kaolin clay is non-toxic to bees and beneficial insects.
Plant Trap Crops
Some plants attract egg-laying by Colorado potato beetles but do not allow larvae to complete development. Intercropping these trap crops near potatoes can pull beetles away and reduce damage.
Eggplant, black nightshade, buffalobur, and hairy galinsoga are effective trap crops for Colorado potato beetles. Plant a perimeter around potatoes or intersperse trap crop plants through the potato rows.
Once they detect the trap crops, beetles will preferentially lay eggs on these plants instead of potatoes. Remove and destroy any trap crop plants with beetle eggs regularly to prevent subsequent generations.
Use Beneficial Nematodes
Beneficial entomopathogenic nematodes can provide biological control of Colorado potato beetle larvae. Heterorhabditis bacteriophora and Steinernema feltiae are two effective species.
The microscopic nematodes are applied to soil where they locate and infect beetle larvae, causing death within 48 hours. Once larvae have been eliminated, apply nematodes again in 2-4 weeks to control any later-hatching larvae. Follow label instructions for timing and rates.
Nematodes require moist soil and are sensitive to ultraviolet light. Apply them in evening or cloudy conditions and irrigate gently afterward. Avoid applying in hot, dry, sunny weather.
Remove Solanaceous Weeds
Colorado potato beetles overwinter as adults in protected places near potato fields. Weeds in the solanaceous plant family like horsenettle, ground cherry, and nightshade provide favored overwintering sites for the beetles.
Removing these weeds from around potato plantings in fall can reduce places for beetles to overwinter, lowering spring populations. Also pull early emerging solanaceous weeds in spring before planting potatoes.
Controlling solanaceous weeds on neighboring properties within 1/4 mile of plantings can also help reduce overwintering sites and spring colonization sources.
Use Spinosad Bait
Spinosad is an organic-approved bacterial insecticide that can be used to make bait for controlling Colorado potato beetle adults. Mix spinosad concentrate with water and a feeding attractant like molasses.
Spot-spray the bait mixture onto areas of plants with active beetles. When beetles ingest the bait, it sickens and kills them within 1-2 days. Make fresh bait for each application, applying when beetles are first seen.
Spinosad has very low toxicity to mammals and is safe for bees. Avoid applying it directly to flowers or when bees are active. Spray it selectively onto affected plant parts only.
Apply Beauveria bassiana
Beauveria bassiana is a beneficial fungus that acts as a natural insecticide. Spores of B. bassiana adhere to Colorado potato beetles and germinate, growing into the insects and killing them within 3-10 days.
Apply B. bassiana fungal spores labeled for organic use according to label directions. Thoroughly spray foliage concentrating on the undersides of leaves where beetles are active.
For optimal effectiveness, apply B. bassiana when larvae first emerge and again 7-10 days later. The fungus persists to infect later generations. It is safe for pollinators and beneficial insects.
Use Diatomaceous Earth
Diatomaceous earth is made from crushed fossils of diatoms, tiny aquatic organisms. The sharp edges of its particles can abrade the waxy cuticle of Colorado potato beetles, causing dehydration and death.
Apply food-grade diatomaceous earth to leaves, especially the undersides where beetles are found. Dust it on early in the morning when foliage is damp for it to adhere. Reapply after rain or overhead irrigation.
Diatomaceous earth provides moderate control and is most effective against young larvae. Avoid breathing the dust yourself when applying. Diatomaceous earth does not harm bees.
Encourage Natural Predators
Numerous generalist predators like lady beetles, lacewings, and ground beetles will feed on Colorado potato beetle eggs and larvae when available. Planting attractive flowering plants provides nectar and pollen to draw in more predators.
Allowing some weeds like dandelions, clover, and dill to grow around potatoes can shelter predators. Providing bird perches or bat houses also brings insect predators to the garden.
With abundant natural enemies, fewer Colorado potato beetle larvae may survive to damage plants. Avoid broad-spectrum insecticides that kill predators. Handpick large beetle infestations that predators can’t contain.
Use a Combination of Methods
Relying on just one tactic likely won’t provide full season control. The best organic Colorado potato beetle management integrates multiple cultural practices, physical controls, and low-risk insecticidal products.
For example, combine row covers for early protection with trap cropping, handpicking, regular applications of neem oil or diatomaceous earth, and encouraging natural predators. This integrated pest management strategy can keep beetle damage minimal without harmful pesticides.
Frequently Asked Questions
What is the best organic way to get rid of potato beetles?
There is no single best method. An integrated approach using row covers, handpicking, neem oil, beneficial nematodes, and other non-toxic products is most effective. Avoiding broad-spectrum insecticides preserves natural biocontrol.
How do I get rid of potato bugs without killing them?
Handpicking beetles and dropping them into soapy water kills them without spraying. Row covers exclude adult beetles so they can’t reach plants. Trap cropping redirects egg laying. These and other methods control potato beetles without broad chemical effects.
What home remedy kills potato bugs?
Some effective home remedies include spraying affected plants with neem oil, dusting with diatomaceous earth, handpicking, and applying beneficial nematodes. Maintaining natural predator numbers also helps control potato beetle larvae. Avoid using home remedies not approved for organic use.
What insecticide can I use on potatoes?
For organic potato production, recommended insecticides include neem oil, spinosad bait, Beauveria bassiana fungus, diatomaceous earth, and Bacillus thuringiensisvar. tenebrionis products. Apply according to label directions to selectively target potato beetles while minimizing harm to bees, beneficial insects, and other wildlife.
Can I spray vinegar on potato plants for bugs?
Plain vinegar can burn and damage vegetable plants. However, some gardeners report spraying a 5% vinegar solution mixed with a small amount of citrus oil deterred Colorado potato beetles on potato plants. Vinegar’s effectiveness is modest and short-lived, so repeated applications would be required. Further research is still needed.
Conclusion
Controlling Colorado potato beetles is critical for growing healthy, productive potato plants. With vigilance and disciplined use of multiple organic methods, potatoes can thrive beetle-free without synthetic pesticides. Prioritize cultural controls like crop rotation, weed removal, and planting trap crops. Supplement these with selective organic insecticides, handpicking, and encouraging natural biocontrol. An integrated approach is key to effective organic Colorado potato beetle management.