Aphid Trap Data

  • The number of cereal aphids caught in Rokeby suction trap (blue line) between the 6th and 12th of September 2018 (Sept Week 2) was 4 and is displayed in the graph below, along with:

- Other aphid numbers for 2018 (Orange line)

- Average weekly temperatures for 2018 (Purple line), Calculated from the mean daily temperature from NIWA CliFlo data for Ashburton (station no. 26170) and 

-The 8 year average of weekly temperatures between 2010 and 2017 ((red line)

- 3 year average of cereal aphid numbers for Rokeby (Green line)

  • Cereal aphid numbers caught in suction traps are an indication of flights and do not replace the need for direct searching16thand monitoring in your crop.
  • Relatively high numbers of aphids are expected till the end of May, with spring flights occurring late September or October
  • Generally the warmer the temperature, the faster an aphid will develop into an adult. However other factors, such as amount of rain, can affect aphid development and survival.                         
  • The number of aphids caught in the suction trap tend to fluctuate relative to the amount of strong wind days and low temperatures.  Low aphid counts do not necessarily indicate the true number of aphids present on the ground.  Installation of weather monitoring equipment at the Rokeby site is being investigated.

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