In modern potato farming, insect pest control remains a critical challenge, especially with aphids and the Colorado potato beetle continuing to cause significant crop losses. Adding complexity is the limited number of insecticides still authorized under European regulations, as well as stricter conditions for their application—especially concerning pollinator protection.
Even one virus-carrying aphid can threaten entire seed potato crops. In the case of planting seed potatoes, where virus transmission is a major concern, preventive strategies are vital, including the use of repellent pyrethroids and frequent monitoring. Once large colonies establish, control becomes nearly impossible.
For consumption potatoes, action thresholds are higher and vary by region:
- In North Rhine-Westphalia, treatment is advised when 500 aphids per 100 compound leaves are observed.
- In Bavaria, this threshold increases to 1,000 aphids per 100 compound leaves.
Aphid infestations can lead to weakened plants and open the door to secondary pathogens like Alternaria, especially when honeydew accumulation begins.
Approved Insecticides for Aphids (as of 2025)
The following insecticides remain approved for aphid control in potatoes, with varying degrees of bee safety:
| Product | Active Ingredient | Bee Toxicity Class |
| Kaiso Sorbie | Lambda-cyhalothrin | B4 (less harmful) |
| Bulldock Top | Lambda-cyhalothrin | B4 |
| Karate Zeon | Lambda-cyhalothrin | B4 |
| Cyperkill Max | Cypermethrin | B1 (harmful) |
| Sumicidin Alpha | Esfenvalerate | B2 (moderate) |
| Teppeki / Afinto | Flonicamid | B2 |
| Para Sommer | Paraffin oil | B4 (only in seed potatoes) |
Important: Always follow local label instructions and national guidelines for application timing, dosage, and environmental precautions.
Bee Safety: Strict Compliance Required
To protect bees, farmers must follow strict application protocols:
- Inspect fields before spraying—blossoming weeds must be absent or treated beforehand.
- Do not rely on early morning inspections alone. Bees may visit recently sprayed fields later in the day.
- Avoid B1-class insecticides unless no bloom or honeydew is present and drift can be prevented with low-drift technology.
- When in doubt, opt out of using B1 products.
Colorado Potato Beetle: Timing is Key
Controlling Colorado potato beetles requires catching the first wave of larvae, ideally at the L2 to L3 stage. If they reach L4, they may pupate and create a second generation, increasing population pressure.
Farmers are advised to use the SIMLEP forecasting model to optimize treatment timing.
Currently approved products for beetle control:
| Product | Active Ingredient | Bee Toxicity Class |
| Mospilan SG | Acetamiprid | B4 |
| Danjiri | Acetamiprid | B4 |
| Carnadine | Acetamiprid | B2 |
| Benevia | Cyantraniliprole | B1 (harmful) |
| Coragen / Voliam | Chlorantraniliprole | B4 |
Rotate insecticides when repeat treatments are necessary to prevent resistance development.
Emerging Threat: Reed Leafhopper (Schilfglasflügel-Zikade)
This insect, a known vector for Stolbur/SBR, has become a growing concern among potato producers. While emergency authorizations for control products have recently been granted for sugar beet cultivation, none have yet been approved for potatoes. The industry continues to push for temporary permissions, especially in regions where the pest is spreading.
In 2025, managing aphids and Colorado potato beetles requires precision, timing, and compliance with bee protection regulations. With a shrinking toolbox of insecticides and increasing pest pressure, monitoring, integrated pest management (IPM), and responsible chemical use are more important than ever. By staying informed and using approved products correctly, farmers can protect their crops—and pollinators—for a sustainable harvest.
