Monitoring aphid numbers in Mid-Canterbury
The status of aphid monitoring using suction trap data
This season FAR has discontinued the monitoring of aphid flights in Mid Canterbury using data from the Plant & Food Research suction trap in Lincoln. Aphid numbers collected at the Rokeby trap have been consistent with those reported in the Lincoln trap in previous years.
Direct-monitoring in paddocks provides a good alternative
The number of aphids caught in suction traps are an indication of flights, but do not represent secondary spread of BYDV within a crop and rely on the amount of cereals grown in the area near the trap. Directly searching your crop will provide the best information about the incidence of cereal aphids in your crop. Searching is best done on sunny afternoons, looking at the underside of leaves. Relatively high numbers of aphids can be anticipated until the end of May, with spring flights occurring late September or October. Click here for more information on integrated pest management (IPM).
Direct-monitoring data is available from paddocks in Mid-Canterbury
As part of FAR’s SFF project, Managing BYDV in cereals sustainably, we are directly monitoring for aphids and beneficial insects e.g. lacewings, hoverflies, parasitic wasps and ladybirds in two autumn sown wheat crops at Methven and Somerton in Mid Canterbury using sticky traps and sweep nets. The 2019 fortnightly average number of cereal aphids (green line) and beneficial insects (yellow line) in direct searches this season are shown in the graphs below, with 0 aphids and 4 beneficial insects found from 26th July to 8th August at Methven and 3 aphids and 2 beneficial insects found at Somerton during the same period.
Figure 1. Aphids and beneficial insects found by direct searching in autumn-sown wheat at Methven, 2018-19.
Figure 2. Aphids and beneficial insects found by direct searching in autumn sown wheat at Somerton 2018-19.