Below is a summary of the numbers of aphids collected and identified. The unidentified aphids recovered in the Stephen trap (No I.D. Species 1 and No I.D. Species 2) are not thought to be PVY vectors, but were present in sufficient numbers to indicate aphid movement in the area. All other aphids mentioned in the count are potential aphid vectors of PVY. Diversity of species catch seemed increased over last week in most trap locations, no soybean aphids were recovered at any location but green peach aphids were recovered from 2 locations (Cando, ND and Gully MN). No potato psyllids were recovered in suction traps from any location but very low numbers of potato psyllids have been recovered over the past 3 weeks in MN and ND from sticky traps monitored by R.D. Offut Co. in a cooperative effort with the Zebra Chip Specialty Crops research Initiative (http://zebrachipscri.tamu.edu).
To scout 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. However, the use of feeding suppressing insecticides, such as Fulfill (Syngenta Crop Protection) or Beleaf (FMC Corp.) 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. In table stock potatoes, a treatment threshold of 30 aphids /100 leaves should deter yield loss due to aphid feeding.
MN/ND Aphid Suction Trap Summary
Aphid Species Captured
|
|||||||||
Cando
ND
|
Forest
River ND
|
Linton
ND
|
Lake
of the Woods MN
|
Gully
MN
|
Stephen
MN
|
Sabin
MN
|
Perham
MN
|
Staples
MN
|
|
Green peach aphid (Myzus persicae)
|
2
|
1
|
|||||||
Soybean aphid
(Aphid glycines)
|
|||||||||
OTHER PVY VECTORS
|
|||||||||
Bird cherry oat aphid (Rhopalosiphum padi)
|
2
|
2
|
1
|
||||||
Corn leaf aphid (Rhopalosiphum maidis)
|
1
|
3
|
1
|
7
|
1
|
||||
English grain aphid (Sitobion avenae)
|
2
|
1
|
2
|
7
|
29
|
6
|
10
|
||
Green bug (Schizaphis graminum)
|
1
|
||||||||
Potato aphid (Macrosiphum euphorbiae)
|
1
|
2
|
1
|
||||||
Sunflower aphid (Aphis helianthi)
|
25
|
||||||||
Thistle aphid (Lipaphis erysimi) |
1
|
||||||||
Turnip aphid (Brevicoryne brassicae)
|
|||||||||
Cotton/melon aphid (Aphis gossypii)
|
4
|
67
|
38
|
5
|
|||||
Pea aphid (Acyrthosiphon pisum)
|
|||||||||
Cowpea aphid (Aphis craccivora)
|
2
|
6
|
1
|
1
|
1
|
2
|
|||
black bean aphid (Aphis fabae)
|
8
|
||||||||
Buckthorn aphid (Aphis nasturii)
|
3
|
||||||||
Identified
non-vector species
|
13
|
9
|
11
|
||||||
Unidentified
|
6
|
||||||||
Total # captured
|
22
|
6
|
83
|
28
|
56
|
23
|
46
|
14
|
|
