Trap Catches Identified to Aug 08.
Here are the trap catches we received up to Aug 08.
It looks like aphids are now moving into potatoes in earnest! We had large increases in almost all trap locations over last week. If you have not started aphid management, it's time to start! Nate reports that over all
trap sites we collected 232 vectors this week compared to 51 last week.
Aphid populations were high across the region and many locations recorded their highest vector numbers of the season. Only
our Linton and Langdon sites saw fewer aphids this week. Bird cherry
oat aphids continue to be our most caught species followed by green bug,
english grain, and corn leaf aphids.
So far, no green peach or soybean aphid (despite soybean aphids being present in soybean fields in low numbers). If the weather starts to favor soybean aphid reproduction, we may yet see this species moving into seed potato fields!
So Keep Scouting!!
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.
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
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.