Apple fruit moth forecast
The apple fruit moth can be a serious pest in apples, but only in years when there are not enough egg-laying sites in rowan berries. The apple fruit moth hatches from overwintering pupae in the spring, and to assess the risk of an attack, one must know both how many rowan berries there were the previous year and how many rowan berries there are relative to the apple fruit moth this year.
The forecast for attacks is calculated for more than 50 weather stations distributed across all fruit districts (see map). The apple fruit moth forecast is a collaboration between local advisors in the fruit districts and NIBIO.
Because the development of the apple fruit moth depends on temperature, the development rate and timing of measures can vary between different districts. To assess the timing, you must have noted when the rowan was in full bloom and calculate the heat sum after that.
You can read more about the apple fruit moth in Plantevernleksikonet and more about the warning model here, or in the information letter VIPS Rognebærmøll.
General messages about forecasts, development, and measures can be found here.
Messages
Rogna blømer godt i år, og meir enn i fjor. På dei stasjonane der det er nok informasjon til å laga eit varsel, er det ikkje fare for angrep.
Det var eit kraftig angrep av rognebærmøll i fjor. Særleg var angrepet stort på Vestlandet. I år blømer rogna godt og det er truleg nok eggleggingsstader i rogn for rognebærmøllen som er på vingene i år. For fleire av stasjonane har me ikkje nok informasjon til å laga eit sikkert varsel, men ved alle desse stasjonane er det meir rogn i år enn i fjor. Då det i tillegg ikkje er varsla angrep i andre fruktdistrikt er det truleg ikkje fare for angrep ved desse stasjonane heller. Det er likevel viktig at de brukar erfaringar frå eigen hage når de vurderar trongen for tiltak.
- High risk of infection
- Medium risk of infection
- No risk of infection
- Forecast not ready
Heat sum for apple fruit moth
The development of the apple fruit moth depends on temperature, so the development rate and timing of measures will vary between districts. To assess the timing, you must have noted when the rowan was in full bloom (50% of the cluster is covered with open flowers) and calculated the heat sum after that.
Select weather data
Foto: Sverre Kobro og E. Fløistad, NIBIO