Tuesday, July 17, 2012

Suction Trap Catches for The Trapping Period Ending July 13
Several traps recorded high captures, mostly of aphids associated with small grains.  As small grains mature and become less suitable hosts, winged aphids will develop in those crops and they will disperse to greener plants, including potatoes. Most of these species are potential vectors of virus in potatoes and should be cues for scouting.

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.

Here's a summary of species and numbers recovered in the suction traps...



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)









Soybean aphid
(Aphid glycines)









OTHER PVY VECTORS
Bird cherry oat aphid (Rhopalosiphum padi)
9
8
14

11

53
4

Corn leaf aphid (Rhopalosiphum maidis)
7

5

5

6
6

English grain aphid (Sitobion avenae)
1
4
3

52
9
4
13
8
Green bug (Schizaphis graminum)









Potato aphid (Macrosiphum euphorbiae)


1

5

9


Sunflower aphid (Aphis helianthi)









Thistle aphid (Lipaphis erysimi)










Turnip aphid (Brevicoryne brassicae)









Cotton/melon aphid (Aphis gossypii)








1
Pea aphid (Acyrthosiphon pisum)







1

Cowpea aphid (Aphis craccivora)

8







black bean aphid (Aphis fabae)








1
Buckthorn aphid (Aphis nasturii)







4

Identified non-vector species







4

Unidentified









Total # captured
17
20
23

73
9
72
30
10