Quick action is essential when addressing the potato beetle, given its swift rate of reproduction and the voracious appetite of its larvae.
Unfortunately, the potato is just one of many plants in the solanaceae family that make up a perfect food source for the alluring but ravenous beetle (Leptinotarsa decemlineata).
Other plants in this family that the beetle targets include tomato and bell pepper.
The adult form of this insect is typically about 10-12 mm long and has a yellow body with a black-spotted head and corset.
The elytra of the insect are marked with five straight black lines. The larva of the insect is orange-red in color and has two rows of black dots along the sides.
Originally from the United States, this insect arrives in Europe in the 20s, quickly causing significant damage to crops in the areas it has invaded.
The resulting famines were so severe that in France and England specific laws were passed to impose the fight against and limit the trade of the affected goods.
Despite these efforts, the control methods available at the time were insufficient, and the insect quickly spread throughout the continent, a problem only exacerbated by the subsequent world war.
The first indications of potatoes infested with beetles
The Colorado beetle emerges during the warmer months, usually around May, after spending the winter underground as an adult.
After taking flight, it seeks out host plants to deposit its eggs. The leaves of these chosen plants will swiftly be devoured by the hungry larvae emerging from the 700 to 2,000 eggs deposited by the beetle.
In just 20-25 days, a new generation of adult beetles is produced, which can continue to lay eggs and start the life cycle again.
This cycle is repeated between June and September, resulting in 2-3 generations per year that can cause significant damage, even to late crops.
Identifying the Colorado beetle is a simple task. Both adults and larvae can be found in sizable colonies that have the ability to consume significant portions of the plant’s foliage, eventually leading to the skeletonization of the plant.
Larvae are the main culprits of this damage, relentlessly consuming leaves, flowers and fruits of the plant.
Protecting potatoes from beetles
The main method of prevention of Colorado potato beetle is the implementation of a comprehensive crop rotation strategy.
Unfortunately, on a small scale such as a family garden, this approach may not produce significant results. The adult beetle can easily reach the potatoes if they move even just a few meters.
One possible approach to protecting potatoes from beetles is through the use of “bait plants”. This tactic involves growing some potato plants in a miniature greenhouse, which are then transplanted in early May.
These plants act as a magnet for wintering adult pests, allowing them to be easily captured and disposed of before they have a chance to infest the crops we intend to protect.
One method of preventing the arrival of the Colorado beetle is to eradicate weeds from the area. This is because many weeds act as hosts for the pest.
Some of the most commonly preferred weeds for the insect include Datura stramonium, Atropa belladonna, Solanum dulcamara, Hyoscyamus niger, as well as ornamental plants such as Aspidistra lanceolata and tulips.
By removing these plants from the garden and its surroundings, the chances of subsequent Colorado potato beetle infestations are greatly reduced.
The use of insecticides approved for organic farming
When it comes to infestations, the use of insecticides is necessary. However, it is important to avoid the use of broad-spectrum products as they not only eliminate the Colorado beetle, but also its natural predators.
The optimal time to intervene is when the first larvae appear, as they are more destructive than adults and are the basis for future generations. There are several options available when considering this course of action.
Organic farming allows the use of Bacillus-based insecticides that clog the digestive tract of insects.
To ensure optimal effectiveness of these products, it is important to wet the area thoroughly and reapply after rain.
It should be noted that these products are approved for use in organic farming practices.
Neem oil containing azadirachtin has several benefits. It has the ability to influence plants through both ingestion and contact, and can permeate through plant tissues and show moderate systemic effects when applied to the roots.
In addition, it acts as a repellent and discourages feeding and can control aphids in case of infestation. In addition, this solution is allowed for use in organic farming.
Due to its high system, acetamiprid is evenly distributed over the entire plant after application.
As a result, it is able to protect the plant from the effects of rain, ensuring that the treatment remains in place for several weeks. Acetamiprid acts by ingestion, fighting larvae and regulating the presence of aphids.
