Aphid Alert 1999, No. 2b, June 22

Summer 1999: Aphid trapping data

Results reported in this issue of Aphid Alert are total captures of winged aphids and species identifications for the following locations and sampling interval end-dates. Additional sampling locations will be reported in next week's issue of this newsletter.

Growers should be aware that green peach aphids were captured last week at Linton, ND. Fortunately, these potential vectors tested negative for potato leafroll when tested by immunocapture-PCR. This first capture of green peach aphid occurred much earlier than our first capture of green peach aphid in 1998. Potato aphids have also been captured at many sites. These two aphids are both potato colonizers and both are capable of transmitting both potato leafroll and potato virus Y (mosaic). Green peach aphid is considered the most important vector of potato viruses.

Also, potato leafhoppers are extremely abundant in 1999. Potato leafhoppers do not transmit potato pathogens, but feeding by this insect can severely damage potatoes. Choose insecticide chemistries and rates with caution to avoid flaring aphids.

With the early arrival of green peach aphid, the high amount of virus inoculum in some seed lots planted this spring, and the wet weather which has necessitated an early initiation of spraying to control late blight, this has the potential to be a very difficult year.