Controlling Colorado Potato Beetle — How To Prevent Potato Beetles
Getting Rid Of Potato Beetles: How To Kill Colorado Potato Beetle
- 1 Getting Rid Of Potato Beetles: How To Kill Colorado Potato Beetle
- 2 Potato Beetle Signs
- 3 Getting Rid of Potato Beetles
- 4 How to Prevent Potato Beetles
- 5 Colorado potato beetles
- 6 Quick facts
- 7 How to identify Colorado potato beetles
- 8 Damage caused by Colorado potato beetles
- 9 How to protect your plants from Colorado potato beetles
- 10 How to get rid of the Colorado potato beetle with mustard and vinegar
- 11 Colorado potato beetle: pest description
- 12 What is harmful Colorado potato beetle
- 13 How to get rid of the Colorado potato beetle, cooking mixture
- 14 How to apply the mixture
- 15 How to Prevent and Deal With Lawn Grubs
- 16 Wreaking Havoc on the Lawn
- 17 How to Know If Your Lawn Has Grubs
- 18 Tips for Dealing With Grubs
- 19 Is There an Organic Product That Can Kill Grubs?
- 20 How to Repair Grub Damage
- 21 Basic insect control
- 22 Potato Pests
Potato beetles are pests of plants in the nightshade family. Potatoes are one plant they devour, but the beetles also eat tomatoes, eggplants and peppers. Both the adults and the larvae eat the leaves of these plants. Getting rid of potato beetles is a priority for the vegetable gardener due to the range of plants the pest can infest. It’s important to know how to look for potato beetle signs so you can be ready to eradicate the insects.
Potato Beetle Signs
Both adult beetles and the larvae feed on the leaves of nightshade plants. The adult beetles are small yellow and black striped beetles. The young are hard bodied red insects with a row of ridges across their humped backs. The young also have a line of black dots along each side of their bodies.
The eggs of potato beetles are bright orange and laid on the underside of leaves. Foliage damage starts out as small holes and becomes larger ragged patches. The damage to the leaves can reduce the vigor of the plant and reduce yield. Controlling Colorado potato beetle will increase your crops and help prevent egg laying and the return of the insect the next season.
Getting Rid of Potato Beetles
Controlling Colorado potato beetle begins with an assessment of the damage. In most cases, the foliar damage isn’t enough to kill a plant but if infestation occurs early in the growing season you should kill Colorado potato beetle. Insecticides should only be used when damage is severe and there is more than one insect per plant. Hand picking can remove many of the pests. A natural bacteria, Bacillus thuringiensis, is useful as a non-toxic control.
Several sprays exist to kill Colorado potato beetle. Timing is an important consideration, in order to get the maximum number of insects. Small larvae are easier to control than adults and mature larvae, therefore, spray when the larvae have just hatched in spring. Use a chemical with pyrethroid or spinosad, which offer control on each species of nightshade.
How to Prevent Potato Beetles
Adult beetles overwinter in the soil and then crawl out to begin feeding and laying eggs. Check the backsides of leaves for the orange eggs and crush them to prevent a future generation of the pests.
Another way how to prevent potato beetles is to keep beds free of debris that gives the adults hiding places. Remove old plants each season and till the vegetable bed. Do not plant nightshade plants in the same location each year but rotate to prevent putting them where the insects already live.
Colorado potato beetles
The Colorado potato beetle (Leptinotarsa decemlineata) is a major potato pest throughout North America.
- Adults become active in spring, about the same time potato plants emerge from the ground.
- Larvae and adults feed on leaves and can completely defoliate plants.
- Many pesticides are ineffective because of pesticide resistance of the Colorado potato beetle.
- A combination of pest management tactics can reduce Colorado potato beetle numbers.
How to identify Colorado potato beetles
Oval in shape and 3/8 inch long.
Biology of Colorado potato beetles
Plants they attack
Colorado potato beetles feed primarily on potatoes. They can also attack other plants in the night shade family (Solanaceae), including:
Colorado potato beetle adults spend the winter 5-10 inches underground in potato fields, field margins, windbreaks and gardens.
In southern and central Minnesota there is generally a second generation. By midsummer, all stages of Colorado potato beetles, eggs, larvae and adults can be present in a potato field.
Damage caused by Colorado potato beetles
How to protect your plants from Colorado potato beetles
Treatment of Colorado potato beetles in home gardens can be challenging. Use a combination of different pest management tactics to reduce Colorado potato beetle numbers.
Keep your garden clean
When Colorado potato beetles first emerge in the spring, they will look for other hosts in the absence of potato plants.
Clean up weeds like nightshade and ground cherry near your garden, as these weeds can act as a possible food source.
Plant early maturing varieties
Plant an early maturing variety to escape much of the damage caused by adults emerging in midsummer.
- Check seed catalogs for varieties that mature in less than 80 days.
- Yields on early maturing varieties are not as large, and often these varieties do not store as well as the popular Russet Burbank potato.
Growing potatoes only every other year may help reduce beetle populations if:
- No potatoes are being grown within a radius of ¼ to ½ mile away, and
- Temperatures are not excessively warm.
Pick beetles off plants
Handpicking in small gardens can be effective.
- Drop adults and larvae in a pail filled with soapy water.
- Remove or crush the yellowish orange eggs on the underside of leaves.
- New adult beetles can fly into gardens so be sure to check your potatoes regularly.
- Handpicking may be less practical in larger gardens.
Natural enemies of Colorado potato beetles
There are a few natural enemies of Colorado potato beetles
- Stink bugs and lady beetles will prey upon Colorado potato beetle eggs.
- The fungus Beauveria bassiana will kill both larvae and adults.
- Unfortunately, natural enemies have little impact on overall Colorado potato beetle numbers.
Colorado potato beetles are resistant to essentially all synthetic pesticides like carbaryl, cypermethrin, deltamethrin, lambda cyhalothrin, imidacloprid, permethrin, and pyrethrins. These products are unlikely to be effective and their use is not suggested.
Anytime you use a pesticide and it does not seem to kill Colorado potato beetles, switch to a different active ingredient.
Colorado potato beetles are not resistant to azadirachtin or spinosad. These products are also “soft” on natural enemies.
- Azadirachtin (Neem) – is derived from the Neem tree of Asia and Africa. It is effective for a couple of days and repeat applications are probably necessary. Azadirachtin provides poorer management of large larvae and adults
- Spinosad – is made from the soil bacterium, Saccharopolyspora spinosa. It is effective for about 10 — 14 days.
CAUTION: Mention of a pesticide or use of a pesticide label is for educational purposes only. Always follow the pesticide label directions attached to the pesticide container you are using. Remember, the label is the law.
Be sure that the vegetable you wish to treat is listed on the label of the pesticide you intend to use. Also be sure to observe the number of days between pesticide application and when you can harvest your crop.
Jeffrey Hahn, Extension entomologist and Suzanne Burkness, College of Food, Agricultural & Natural Resource Sciences
How to get rid of the Colorado potato beetle with mustard and vinegar
The Colorado potato beetle is a species of insects from the family of leaf beetles, a subfamily of true leaf beetles.
Discovered in 1824 by the entomologist Thomas Sayem, one of the most dangerous pests of solanaceous crops.
Currently, not only chemical insecticides to fight the beetle, but also folk remedies for the Colorado potato beetle have gained wide popularity.
Did you know? Despite the fact that the insect got its name after the devastation of potato fields in the state of Colorado in 1859, its homeland is the Sonoran province in northeastern Mexico.
Colorado potato beetle: pest description
The body of the Colorado potato beetle is oval in shape, 7–12 mm long, on top is convex, yellow, the head and prothorax are covered with spots. On each wing there are five longitudinal black stripes.
Differs in exceptional fecundity — for the life of the female, on average, they lay up to 800 eggs, arranged in small groups of 30-40 pieces each. After 10-15 days, fleshy larvae appear in eggs, their life lasts 25 days.
At the larva stage, four ages are distinguished, which are separated by molts. At the first and at the second age, the larvae have a dark brown color; at the third age, the larva acquires an orange, pink or yellow-orange shade. Their head, legs and two rows of warts on the sides of the body are black.
In the first and second instar, the larvae remain in groups on the tops of the shoots; in the third and fourth, they transfer to neighboring plants. During the pupation period, most of the larvae burrow into the soil to a depth of 10 cm at a distance of 10–20 cm from the bush, which they ate.
The pupa is formed in 10-20 days. In the fall, beetles burrow 70 m into the soil and freeze until spring, getting to the surface only after the temperature rises to 15 ° C.
In calm weather, the speed of flight of beetles — 4-8 km per hour. Getting into the water, the beetles do not sink, the current of the river carries them away, giving the opportunity to crawl out to the shore.
Did you know? The intense orange color of the larvae is a sign of the presence of carotene coloring matter in their bodies.
What is harmful Colorado potato beetle
Each year, the owners of the dachas raises the question of how to get rid of the Colorado potato beetle. The Colorado potato beetle has insatiable gluttony; it destroys potatoes, stems, leaves (in spring), flowers (in summer), tubers (in early autumn). As soon as the temperature decreases, the pests burrow into the soil.
The gradual movement of the plant means imminent damage, because the number of beetles increases with time, which puts even more fruit at risk. The beetle, besides potatoes, eats eggplants, tomatoes, sweet peppers with pleasure.
Important! The beetle is a long-lived record holder who overcomes his hungry years, falling into a 2-3-year pause, after which he is able to give healthy offspring.
How to get rid of the Colorado potato beetle, cooking mixture
Mustard will quickly and safely get rid of the Colorado potato beetle.
Summer residents planted mustard to scare away insects so that it does not allow weeds to grow and improve the structure of the land.
Thanks to its ability to grow rapidly, cleansing the land from phytophthora and scab, not leaching the soil, it helps to fight wireworm, pinworm, slugs.
It has a positive impact in the fight against the Colorado potato beetle. It is best to plant the mustard between the rows of potatoes and eggplants, pick during the flowering period and spread out between plants that can become victims of the Colorado potato beetle.
Vinegar is also useful against the Colorado potato beetle. In vinegar is acetic acid, complex alcohols, esters and aldehydes, and acetic essence of 80% of the concentration can destroy the insect when it penetrates inside.
But the best effect will be a mixture of mustard and vinegar. For her cooking 100 g of mustard powder and 100 ml of 9% vinegar should be diluted in one bucket of water.
Exists another version of the mustard-vinegar mixture: 200 g of mustard powder diluted in 10 liters of water and insist 12 hours, then add 150 ml of vinegar. Also, turpentine, an infusion of onion peel, garlic or wormwood can be added to the remedy for the Colorado potato beetle, which will enhance the effectiveness of a folk remedy.
How to apply the mixture
In order for mustard and vinegar against the Colorado potato beetle to work, you should follow the rules in the manufacture and use of the solution. It is necessary to process potato tops at the beginning of growth and when the number of beetles increases during flowering.
It is better to make spraying in the evening, when the heat of the day subsides, in warm and calm weather.
For processing, a large amount of the solution will be required, spraying should be done regularly, but treatment should be stopped 20 days before the estimated harvest. A solution of pure vinegar should not be watered. When processing tops, try to prevent the mixture from dripping. Mustard and can be watered and sprayed leaves.
You also can not forget that the use of the solution over 3 hours does not make sense, it must be made immediately before use. Mustard in the fight against the Colorado potato beetle will be powerless if carried out spraying under the influence of direct sunlight: it will lose its qualities, and the entry of rain drops can simply wash away the solution.
It is undesirable to use the mixture after rain, after abundant dew, in foggy weather, during strong winds. The best time to process is pre-sunset evening.
Important! The main harm to the plants is not brought by adults, but by the larvae at the third and fourth age of development, therefore the fight with the beetle cannot be postponed.
The use of folk remedies has the main advantage over chemical preparations — they are absolutely safe for people, animals, plants and the environment due to the fact that they are non-toxic.
How to Prevent and Deal With Lawn Grubs
Wreaking Havoc on the Lawn
Greg Schechter / Flickr
Typical lawn grubs, often called white grubs, are white, C-shaped beetle larvae about a half-inch in length. A grub may be the larvae of the masked chafer, European chafer (pictured), Japanese beetle or other beetle species. Lawn grubs have soft bodies with legs near the head. They feed on grassroots (and organic matter in the soil), causing sections of grass in the lawn to die. Grubs eventually turn into adult beetles and emerge from soil to mate and lay eggs, which hatch into more grubs.
How to Know If Your Lawn Has Grubs
If you can pull sod away from the ground, the root system may have been eaten by grubs. Cut into the soil and look for their presence. More than 10 grubs per square foot is a red flag.
The presence of grubs may be an indication that beetles are laying eggs in your lawn. Tan-colored chafer beetles are active just after sundown; Japanese beetles can be seen flying during the day, feeding on ornamentals.
Grub damage can appear in two ways. First, small irregular patches of a lawn will appear brown, dry and wilted. Damage also occurs when raccoons and crows tear up the lawn to feed on grubs. Both types of damage can be extensive during a severe outbreak.
Tips for Dealing With Grubs
An active IPM program is the best plan for dealing with any lawn pests. Periodic scouting is the best defense, especially in late in the summer when grub damage is greatest.
If you have cut into the soil and determined that an outbreak has occurred (indicated by more than 10 grubs per square foot), an insecticide such as Dylox could be used. (Insecticides such as Merit help prevent grubs while in the egg stage.)
Insecticides are dangerous and best handled by a licensed pesticide applicator.
Is There an Organic Product That Can Kill Grubs?
The best organic grub control is prevention. Beetles lay their eggs in moist, irrigated soil. A natural alternative is to avoid watering during mid-summer dry spells. The lawn may turn brown and go dormant, but a grub problem is less likely.
Healthy soil and Integrated Pest Management give you the upper hand in grub defense.
Milky spore is a naturally occurring bacterium that can help control grub populations in USDA weather zones 7 through 10. When the soil is inoculated with milky spore, the grubs inadvertently eat the spores while feeding and die, releasing millions of more spores. It can be a lengthy process, but it is organic.
Some nematodes are natural enemies of white grubs. There are many different types of nematodes, some beneficial and others not. Hb nematodes are watered into the soil to introduce a natural grub predator.
How to Repair Grub Damage
Because the grubs feed on the roots, grass will need to be started from scratch. Just treat the area like any other bare patch repair and be certain to keep the seed moist while germinating.
Basic insect control
Although insects are known to target weak plants, even the best gardener has to deal with some insect infestations. Being able to recognize and treat these attacks early is vital to keeping the whole garden healthy.
Integrated Pest Management (IPM): IPM is a way of minimizing the damage caused by insects while at the same time using the least toxic remedies. Key to treatment is correct identification of the insect that is damaging your plant. When you know the insect you can learn about the life cycle and treat it at the best stage of growth. For a many insects the best stage is to treat or remove the eggs which are generally found under the leaf. Removal of the whole leaf forestalls any further damage to a plant. Sometimes it is worth allowing a little bit of damage if you know that the life cycle of the insect is limited to just a week or two.
It is also important to watch for problems in the garden. Many infestations can be avoided if you walk around the garden frequently and treat the problem before it gets out of control.
Treatment Options: Whether you have children or not, it is environmentally healthier to use the least toxic insect treatment. For tiny eggs and very small whiteflies, this can be as simple as a strong stream of water from a hosepipe. More sticky insects which cover themselves with a hard shell need an oily soap which covers the shell and kills the insect inside. Common dish soap in solution works well for many of these insects.
Common Insect Types:
Worms: There are numerous worm-like insect that can affect the garden, some of which are specific to a host plant, and others enjoy a variety of plants. In general the worms eat the soft tissue of the leave and smaller ones burrow into the leaf itself to feed on the interior fluids. Green Cabbage Loppers, pale Canna Leaf Miners, and Army Cutworms are just some of the wormlike creatures. Removal of the egg stage is the best remedy but as we rarely see the eggs it is necessary to treat the insect. Cutworms, which affect newly planted seedlings, can be avoided by putting a ÔcollarÕ round the plants to protect them.
Beetles: Beetles have hard coats and can be seen marching across the leaf, chomping as it goes along. Colorado Potato Beetle, Japanese Beetle and the Cucumber Beetle are all common in garden across the continent. It is best to be vigilant with your garden and treat the egg/grub stage before you have problems. Beetles are usually large enough that they can be physically removed and thrown into a bucket of soapy water. Covering the crops before the beetles arrive also prevents damage.
Crawlers/Flyers : These are the smaller creatures, many of which are microscopic. The damage from just one of these creatures is not large, but they usually arrive en masse and cause anything from disfigurement to leaf damage. Aphids, Mealy Bugs and Spider Mites like a variety of hosts and are common particularly in summer. Many of these creatures need a horticultural soap to wash them off.
Most gardens will be affected by a few insects, but finding them early, identifying them correctly and treating the problem early will keep the garden healthy without excessive chemical use.
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ENTFACT-304: Potato Pests | Download PDF
by Ric Bessin, Extension Specialist
University of Kentucky College of Agriculture
The local market for potatoes from Kentucky has resulted in increased interest in the crop by potential growers. Growing a new crop often means dealing with a different pest complex. This publication was prepared to provide information on the biology, identification and control of potato pests. More on specific information on insecticides is available from ID-36, «Commercial Vegetable Crop Recommendations».
Soil insects, primarily wireworms and white grubs, can severely damage seed pieces and tubers. These insects feed on grass roots and should be considered as a serious threat when potatoes are to be grown in ground immediately following sod.
Figure 1. Wireworm damage leaves holes in tubers.
In these situations, a pre-plant broadcast application of a soil insecticide should be considered. For best results, treat after soil temperature at the six inch depth has reached 50°F. By this time soil insects should be active and nearer the surface.
Figure 2. White grubs produce large holes in tubers.
The threat of damage by soil insects is lessened with time out of sod. Because some wireworms and grubs spend two or more years in the soil a problem may still occur. A planting-time soil treatment should be sufficient in these cases.
Colorado Potato Beetle
The common black and yellow-striped «potato bug», a very familiar insect, is the most serious pest of potatoes. Both the adult, or beetle, and the black-spotted, red larva feed on potato leaves. Their damage can greatly reduce yield and even kill plants.
Figure 3. Colorado potato beetle has alternating black and white stripes on its wing covers.
In addition to potato, Colorado potato beetle can be a serious pest of tomato, eggplant, and pepper. Colorado potato beetle overwinters in the soil as adults. The Colorado potato beetle is a yellow insect with alternating black and white strips down its back. They become active again in the spring and feed on weeds and volunteer on early-planted potatoes. They will even enter the soil to attack emerging foliage. Female beetles lay batches of about two dozen orange-yellow eggs on the underside of the leaves. Each female can lay 500 or more eggs over a four to five week period. The eggs hatch in four to nine days and the larvae begin to feed on potato foliage. The larvae are humpbacked with two rows of black spots. The larvae usually feed in groups and damage can be severe. The larval stage lasts two to three weeks.
Full grown larvae move to the ground and change into an inactive or pupal stage. In five to 10 days the new adult beetles emerge. This insect can go from egg to adult in as little as 21 days. They feed for a few days, before egg laying begins. There are two full and occasionally a partial third generation each year. If foliar sprays are used, an effort should be made to treat after most eggs have hatched but before serious plant damage occurs.
This insect is notorious for development of resistance to insecticides over short periods of time. A rotation among different classes of insecticides is recommended to discourage resistance. There is a new commercially available strain of Bacillius thuringiensis (var tenebrionis ) that are effective against small larvae (less than 1/4 inch) and should be applied at egg hatch or when larvae are first seen. A premature treatment may lose much of its effectiveness before the eggs hatch. An insect growth regulator, called Align, has also been released for control of this insect. It is an extract of the neem seed that prevent the insect from developing normally.
The Colorado potato beetle, Leptinotarsa decemlineata , can be easily confused with its close cousin the false potato beetle, Leptinotarsa juncta . While these two insects look nearly identical, only the Colorado potato beetle is a serious pest. While the adult false potato beetle has alternating black and white strips on its back as well, one of the white strips in the center of each wing cover is missing and replaced by a light brown strip. The eggs are slightly larger and fewer found in a cluster. The humpbacked larva is similar, but with only one row of dark spots on each side. False potato beetles are frequently found feeding on some solanaceous weeds, such as horsenettle, but do no growth and reproduction occurs when feeding on potato.
Figure 4. In some years aphids can be problematic.
Winged aphids may move into potato fields in significant numbers. These migrants settle on the leaves and begin to remove plant sap. During this period they are also capable of producing large numbers of wingless aphids that in turn place an even greater stress on plants.
Distorted leaves and «sticky» leaf surfaces are signs of aphid infestation. Natural enemies and diseases can often keep aphid populations under control. Limiting the use of broad-spectrum insecticides will conserve predators and parasites that help keep aphid populations under control.
Potato leafhoppers are wedge-shaped, 1/8-inch long, green, active insects. They use their piercing-sucking mouthparts to remove sap from the potato leaf. These small insects fly readily. Because of their small size and habit of feeding on the underside of the leaf, they are easily overlooked.
Figure 5. Potato leafhopper migrates from southern overwintering areas each summer.
The symptom of leafhopper activity is more apparent — a triangular brown spot at the tip of the leaf. Similar triangles may appear at the end of each lateral veinlet or the entire margin may roll upward as though scorched. These symptoms are known as «hopperburn». Other conditions may produce similar symptoms. Check the underside of leaves for the tiny leafhoppers to confirm that they are the cause of the problem.
Potato leafhoppers do not overwinter in Kentucky. Winds carry them into the state each year from the Gulf Coast. They generally appear between May 25 and June 5. Within a few days after mating, females lay their eggs in the stems and larger leaf veins of succulent plants. The eggs hatch in about 10 days into the immature or nymphal stage. The light green, wedge-shaped nymphs are smaller than the adults and do not have wings. Both stages are very active. Adults jump or fly readily when disturbed while the nymphs run sideways across the leaf and over the edge.
Development from egg to adult takes about three weeks in warm weather. Very large leafhopper populations can build up in a short time during the summer.
A variety of other insects may be numerous at times. Control decisions should be based on the extent of the infestation in the field and the severity of damage.
Figure 6. Blister beetles can attack a variety of vegetables.
Blister beetles are narrow, elongate insects. They may be found feeding in clusters on potato leaves. Infestations are usually localized within fields and treatment of an entire field is seldom necessary. Rarely do blister beetles do enough damage damage to cause any yield loss.
Hornworms are easily identified and will feed on potato foliage. These worms can consume large amounts of foliage but severe infestations are not likely to occur. Hormworms can easily be controlled using any of the insecticides containing Bacillus thuringiensis var kurstaki. Rarely do hormworms cause losses to potato yields.
Figure 7. Flea beetles leave characteristic small round holes in leaves.
Flea beetles cause the small shot-hole damage to leaves. These tiny beetles overwinter as adults and may appear in fields very early in the season and cause serious damage to young plants. Sevin provides very good control of flea beetles when they are numerous on small plants.
Planting time use of systemic insecticides allows protection against moderate levels of soil insects plus activity against leaf-feeding pests such as aphids, leafhoppers and flea beetles. Insecticidal effects are generally greatest during the early part of the growing season. Read the label thoroughly and observe pre-harvest intervals carefully.
A variety of insecticides may be used on potatoes to control insect pests. Repeated sprays may be needed in some years, especially against late season pests. See ID-36, «Commercial Vegetable Crop Recommendations» for recommendations.
Colorado Potato Beetle Resistance Management
The Colorado potato beetle is notorious for its ability to rapidly develop resistance to insecticides that are used repeatedly to control it. This has been a serious problem on the east coast for some time, and is becoming more of a problem in Kentucky. With a more limited number of available insecticides, some homeowners feel they have exhausted their control options.
Resistance develops more rapidly to an insecticide when that insecticide is used repeatedly as the only control measure. Often over use of one insecticide may favor the development of resistance to other insecticides in the same chemical class. Insecticides in the same chemical class usually have the same mode of action , i.e. the same method of killing the insect. Consequently, to delay or prevent resistance it is important to avoid repeated usage of one particular insecticide by rotating the insecticides used. Rotation needs to be among different classes of insecticides.
Other control measures such as hand picking of adult beetles and immature stages will also aid to delay the development of resistance. Resistance by Colorado potato beetles should be managed on a field-to-field basis. While they may be resistance to one insecticide in a particular field, those in other fields within the same county may not have developed resistance to that insecticide.
CAUTION! Pesticide recommendations in this publication are registered for use in Kentucky, USA ONLY! The use of some products may not be legal in your state or country. Please check with your local county agent or regulatory official before using any pesticide mentioned in this publication.
Of course, ALWAYS READ AND FOLLOW LABEL DIRECTIONS FOR SAFE USE OF ANY PESTICIDE!