Because potatoes are grown for their edible tubers, they must receive greater protection from soil-inhabiting pests. Wireworms, tuberworms, white grubs, and vegetable weevils are pests that growers should monitor stringently.
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.
Wireworms (the larvae of several species of click beetles) and white grubs (the larvae of May/June beetles) occasionally feed on potato tubers. Wireworm feeding results in small, round holes in tubers. White grub damage appears as shallow, irregular gouges in tubers.
Powder the potato plants with food-grade diatomaceous earth. The bag of diatomaceous earth comes with a tool to blow it on the leaves. It's recommended to do this after a dewy morning or rain so it sticks to the leaves. The potato bugs do not like crawling on this powder.
The first-choice products are the synthetic pyrethroids such as permethrin, cyfluthrin and esfenvalerate. Look for products labeled for use on potatoes in the home garden and apply according to label directions, including spray early, spray often.
Keeping marigolds in your organic garden is one of the best ways to prevent pests naturally. Marigolds' scent is naturally repellent to many common pests, including Colorado potato beetles.
Insects include lacewings (Neuroptera: Chrysopidae), predatory stink bugs (Hemiptera: Pentatomidae, subfamily Asopinae), parasitic flies (Diptera: Tachinidae), predatory beetles (Coleoptera: Coccinelidae, Cicinilidae, Staphylinidae and Carabidae) and parasitic and predatory Hymenoptera.
The number of potato bugs can be controlled by predatory insects such as ladybugs and parasitic wasps. Bacillus thuringiensis (Bt) and other biological insecticides target and kill pests without harming beneficial insects or the environment.
Cause: The cause of the problem are the larvae of either the “click' beetle or the tuber flea beetle. While the damage due to these beetles is very similar, the prevention is somewhat different.
To combat these pests, go for insecticidal soap or neem oil, which suffocate and break down their defenses. Regular leaf inspections are non-negotiable.
Sevin Dust protects carrots, onions, celery, cabbage, peppers, potatoes, spinach, cherries, strawberries and many more listed fruits and vegetables from pests and diseases like thrips, mites, red spiders, powdery mildew, leaf spot, black spot, and many more. Do not dust on open blooms to protect pollinating insects.
While slicing my potatoes, I noticed a brownish ring in the flesh all around the outside of the potatoes. This condition, called vascular discoloration, is similar to net necrosis. Dry growing conditions cause the vascular ring, which extends around the entire tuber. This condition is not harmful.
Each year, Late blight reduces the yields of potatoes and tomatoes in the field and can cause major losses in potato tubers in storage. Late blight is found in most potato and vegetable growing regions of Canada and North America.
Potato leaves commonly darken at the edges with white mould occurring at the paler edges of the dark patches followed by destruction of the entire leaf. Tubers can become infected and rot in the ground (or later in storage) unless foliage is removed promptly when blight has been spotted.
The adult stages of white grubs are scarab beetles. Common names for some of the species include June beetles, chafers, and dung beetles. Only a few species of white grubs' damage turfgrass, and most feed on decaying plant material and animal manure, proving a necessary role in recycling nutrients of these materials.
Adult wireworms are slender, reddish brown to black click beetles that are 0.25 to 0.5 inch long. The larvae are wirelike, having hard bodies that are slender, cylindrical, yellowish to brown in color, and about 0.75 inch long when full grown. Common wireworm species require 3 to 4 years to complete their life cycle.
Over-watering leads to yellow leaves, soggy soil, and root rot. Adjust watering with growth stages and soil moisture for healthy potatoes.
Just cut off the holey bits and the rest will be fine to eat.
Pyrethroids and organic pyrethrins (Groups 3 and 3A) are contact insecticides (e.g., Asana and PyGanic [Valent], Mustang [FMC], Warrior [Syngenta]. Some other contact insecticides used on potatoes are Aza-Direct and Imidan [Gowan], Lannate [Corteva], Rimon [UPL], Torac [Nichino America].
Stink bugs and lady beetles will prey upon Colorado potato beetle eggs. The fungus Beauveria bassiana will kill both larvae and adults.
Acidity of the vinegar is potent enough to kill many pests. Vinegar is often used as a contact type insecticide, which means that you need to spray it directly onto the spotted bug to make it effective. Vinegar is basically an aqueous solution composed of water and acetic acid.
Diatomaceous earth contains no toxic poisons and works on contact. Dust lightly and evenly over vegetable crops wherever these potato bugs are found.
Grow plants that repel Colorado potato beetles, like eucalyptus, catnip, marigold, nasturtium, coriander, onion, and tansy.
Are Potato Bugs Venomous? Jerusalem cricks are not poisonous but their bite can be painful.