Here are the trap catches from the sites we received. Note that sites are on different schedules to send in trap catches (spreading out our identification workload). As more sites come in, we'll identify their trap catch and update the site on the fly.
A lone green peach aphid, the most efficient PVY vector, was collected from Hoople and Buckthorn aphid showed up at several sites. Overall though, aphid numbers remain low with no aphids collected at several sites.
By next week we hope to have all sites up and running in order to represent aphid populations across the entire seed potato growing regions of Minnesota and North Dakota.
We wish everyone a happy and safe Fourth!
Until next week…
Scouting for aphids in potatoes:
- Select leaves from the lower to mid canopy. Lower, older leaves will have more established colonies and aphids prefer the balance of nutrients found here; aphids are rarely found on leaves in the upper canopy.
- Avoid leaves on the ground or in contact with the soil.
- In seed potatoes there is only a threshold for PLRV (10 aphids/100 leaves), reactive application of insecticides an effective control for PVY.
- The use of feeding suppressing insecticides, such as pymetrozine (Fulfill®) or flonicamid (Beleaf®) and refined crop oils, such as Aphoil and JMS Stylet Oil, at or prior to field colonization by aphids may reduce the transmission of PVY within fields. Some other insecticides, such as clothianidin (Belay®), imidacloprid (Admire Pro® or Provado®), and spirotetramat (Movento®), have also been demonstrated to reduce the transmission of PVY.
- In table stock potatoes, a treatment threshold of 30 aphids /100 leaves should deter yield loss due to aphid feeding.