Emhlabeni Wonke: I-Colorado Beetle Isindile Kuma-Pyrethroids Njengoba Ukufa Kwehla Kuya Ku-0–55% Ngesilinganiso Sensimu
Ukuthatha okhiye
- 69 beetle populations tested in Czechia from 2017 to 2022
- 0–55.2% mortality with lambda-cyhalothrin at field rate
- 3,132 was the top acetamiprid resistance ratio recorded
- 1 chemistry class per generation, 1 in 4 generations max
Kungani kubalulekile
- Kwabalimi
- Bhala uhlelo lokufafaza ngeqembu le-IRAC ngesizukulwane ngasinye sebhungane futhi ungasebenzisi ikilasi elilodwa ngokumelene nezizukulwane ezingaphezu kwesisodwa kwezine
- Okwamaphrosesa
- Cela abalimi bezinkontileka ukuthi bakunike uhlelo lwabo lokushintshanisa amabhungane, njengoba ukufutha okwehlulekayo kusho ukuthi amahlumela aphuma futhi izimila ezincane ziphuma.
- Kwabahlinzeki
- Check local resistance data before recommending pyrethroids or neonicotinoids for beetle control and offer a rotation partner for diamides
60-isekhondi isifinyezo
Many Colorado potato beetle populations no longer die from the doses farmers apply, so the choice of insecticide group now decides whether a spray pays. A Czech team followed 69 populations for six years. With the pyrethroid lambda-cyhalothrin, kill rates stayed between zero and about 55%, and chlorpyrifos did little better. Acetamiprid worked well on some farms and failed on others, with a resistance ratio of up to 3,132. Chlorantraniliprole still killed at least 86.7% of beetles. Cornell extension advice turns this into a rule: one chemical class per generation, and each class against no more than one generation in four. Several neonicotinoid brands share IRAC Class 4, so swapping labels does not count as rotating. The limitation is geography: the tests covered Czech populations only, and resistance differs between regions, so local testing is the safest guide before a spray programme is fixed.
Colorado potato beetle populations can survive standard insecticide doses, a six-year study from Czechia shows. Researchers tested 69 beetle populations between 2017 and 2022. The results were published in the journal PLOS ONE on 6 May 2024.
The pyrethroid lambda-cyhalothrin gave very low mortality at the recommended field rate. Mortality ranged from 0% to 55.2% between populations. No population sensitive to this active ingredient was found. The organophosphate chlorpyrifos gave 0% to 64.3% mortality in tests from 2017 to 2020. Again, the authors recorded no sensitive population.
Neonicotinoids gave mixed results. Mortality with acetamiprid ranged from 3.3% to 100%. The resistance ratio between populations reached 3,132. For thiamethoxam, mortality ranged from 79.3% to 100%, with resistance ratios from 2.3 to 28.6. The diamide chlorantraniliprole remained effective. Mortality was 86.7% to 100% in tests from 2020 to 2022, and the authors saw no loss of sensitivity.
Izinsuku zeviki. Zikhiphe ohlwini ngokuchofoza okukodwa.
Rotation by beetle generation
Extension guidance from Cornell University in the United States gives a simple rule. Only one class of chemistry should be used against a single beetle generation. Each class should be used against only one generation out of every four on a farm.
The guidance notes that about two dozen products are available for beetle control. They span more than eleven classes of chemistry. So a real rotation is possible on most farms.
Cornell also warns about one group in particular. Many neonicotinoid products belong to the same IRAC Class 4. Switching between brand names within this class is not a rotation. The guidance adds that one imidacloprid product had been used on some farms every year since 1995.
Kungani kubalulekile
The beetle adapts fast when the same mode of action is used year after year. The Czech data show that older pyrethroids and organophosphates may no longer control many populations. Growers who still rely on them may pay for sprays that do little.
A written rotation plan by IRAC group is the practical answer. Farms should record which group was used against each generation. Local resistance tests, like those in the Czech study, show which groups still work in a given region. The diamide result is good news, but it also shows which group needs the most protection now.
Ukuvimbela nokulawula · Inothi lokuhlela
Colorado potato beetle (Leptinotarsa decemlineata): what growers can do
- Prevention: Rotate fields away from last year’s potatoes and control volunteer amazambane.
- Ukuqapha: Scout for egg masses; treat small larvae at the local threshold.
- Ukuvikelwa kwamakhemikhali: Chlorantraniliprole (IRAC 28), spinosad (IRAC 5), pyrethroids (IRAC 3A), neonicotinoids (IRAC 4A; not approved for field use in the EU and UK). Check the national register of your country.
- Ukuphathwa kokumelana: Use each IRAC group against only one beetle generation per season. Do not repeat group 4A after a seed-tuber treatment.
Leli nothi linikezwa yithimba labahleli be-potatoes.news ukuze lithole ulwazi kuphela. Akuyona incomo yanoma iyiphi inkampani futhi akuyona impoqo. Sebenzisa kuphela imikhiqizo yokuvikela izitshalo egunyaziwe ezweni lakini bese ulandela ilebula. Amagama omkhiqizo nokubhaliswa kwawo kuyahluka phakathi kwamazwe; xhumana nochwepheshe wezolimo wendawo.
Photo: Colorado potato beetle on a potato plant (illustrative). Hélène Rival / Wikimedia Commons, CC BY-SA 4.0
Isifinyezo Samazambane Omhlaba Wonke
Izindaba ezinhlanu eziphezulu, amanani, izexwayiso zezifo kanye nemicimbi. Ekuseni phakathi nesonto, akukho ukukhangisa.
Imithombo
- PLOS ONE — Six-year monitoring of pesticide resistance in the Colorado potato beetle during a neonicotinoid restriction period (Kocourek et al., 6 May 2024) — https://pmc.ncbi.nlm.nih.gov/articles/PMC11073731/
- Cornell University, B. Nault — Control of Colorado Potato Beetle & Insecticide Resistance Management — https://rvpadmin.cce.cornell.edu/pdf/submission/pdf54_pdf.pdf
Kuxhunywe kulokhu okuqukethwe
- Izwe
- Umhlaba
- Izinkampani
- Cornell University; PLOS ONE
Izindaba ezihlobene
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ICameroon: Umkhiqizo Wamazambane Ukhuphuke Ngokuphindwe Kayi-18 Kusukela Ngo-1961 Waya Kumathani Angu-370,206, Kodwa Isivuno Sihlala Siseduze Nama-t/ha angu-10.6
