The Colorado potato beetle is an enemy well known to potato growers. It has already caused massive damage in some fields this season.
- Colorado potato beetle larvae feed intensively on many plantations.
- Damage caused by the beetle may, in extreme cases, lead to an almost complete reduction in yield.
Colorado potato beetle larvae have been feeding intensively for several days
Typically, mass occurrences of the beetle, the larvae of the first generation, are recorded from around mid-June. Of course, this is not a rule, because the pest’s development cycle also depends on meteorological conditions. This year, at the end of May/beginning of June, the local scale of damage caused by the beetle to potato plantations was considerable.
Weather conditions – high temperatures and lack of rainfall – favored the development of the pest. It is true that they are slightly worse at the moment, but not enough to significantly slow down the development dynamics of the Colorado potato beetle.
The pest signaling platform already recommends treatments in several locations. However, remember that it is a reference point. Severe damage caused by the feeding of beetle larvae is observed in many regions. In Lower Silesia, on some plantations, the treatment should be performed “yesterday”.
How large are the yield losses due to the presence of the Colorado potato beetle?
With heavy feeding, yield losses of up to approximately 80 percent may occur – if protection is not applied at the right time. In turn, if there is no chemical protection, there is a risk of almost complete destruction of the plantation. While damage to the leaf blade leads to a reduction in the assimilation surface of the plant, mass feeding even results in complete damage to the shoots. When the Colorado potato beetle infestation is high, barren spots will appear on the plantation.
After consuming the leaves, the Colorado potato beetle looks for other food sources – then it moves to the side shoots and the stem. If these are also eaten, the beetle will spread to the tubers.
Losses due to beetle feeding are increasing exponentially. It is estimated that damage to 15-20 percent of the leaf mass may result in a yield loss of 25-35 percent. The greatest damage is noted in the marginal areas of the plantation, where the most beetles usually appear and the larvae feed with the greatest intensity.
As in other crops, in potatoes we do not have much room for maneuver when it comes to protection against pests. To combat the Colorado potato beetle, several active substances are registered on the Polish market, including acetamiprid, chlorantraniliprole, cypermethrin, cyanotraniliprole, azadirachtin, deltamethrin, lambda – cyhalothrin, tau fluvalinate, spinosad.
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