Trap Catches Identified Week of Aug01-05

Greetings!

Aphid vector numbers still remain low in most areas as does the associated PVY Vector Risk Index values.  The annual Soybean aphid summer dispersal flight hasn't yet started, although numbers of soybean aphid are variable throughout MN and ND, most soybean fields are in reproductive stages, meaning we'll see more winged aphids developing from those fields.

While aphid numbers remain low, there have been reports of potato psyllids in western and south central ND.  These insects are the vectors of the Liberibacter bacterium that causes Zebra Chip.  We don't yet know if the psyllids recovered this year are infectious with ZC  but tests are underway.  Even psyllids not carrying the Liberibacter bacterium can injure potatoes via toxins in their saliva injected into the plant when they feed.  This can cause "Psyllid Yellows", characterized by yellow or purple leaves, reduced tuber number and size, malformed tubers, and chaining of tubers.  Scouting and management options are outlined in a Psyllid Management publication which will be posted on the NDSU Potato Extension Webpage (https://www.ag.ndsu.edu/potatoextension), 

Meanwhile. we're still not out of the woods for aphids...

 

Table of Trap Catches Identified Aug 01-05

 

Graph of Seasonal Trap Catches to Aug 01