Wed., August 29, 2012 (graphs updated Jan 24, 2013)

Here's the catch for the Trapping Period ending Aug29.

Green Peach aphid were recovered from both Cando, ND (1) and from Lake of the Woods, MN (7).  No soybean aphids were recovered in any trap.  If seed potato vines have not yet been killed at these sites, it should be noted that green peach is the most efficient vector of PVY.   The presence and flight of soybean aphids remains low. Southern MN is reporting increased soybean aphid populations but few apparently dispersed to northern areas.  

There were significant flights of Bird Cherry Oat aphid in Lake of the Woods and Corn Leaf aphid in Linton ND, Sabin and Perham MN.  Linton, ND also had a significant flight of cowpea aphids as did Staples, MN.  Lake of the Woods also had a very heavy flight of Buckthorn aphids, probably returning to Buckthorn, their overwintering host.  Individual vector aphids of several species were found at several other locations (see table).

As always - 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.

	Aphid Species Captured (per suction trap) 8/15 – 8/29
	Cando ND	Forest River ND	Linton ND	Lake of the Woods MN	Gully MN	Stephen MN	Sabine MN	Perham MN	Staples MN
Green peach aphid (Myzus persicae)	1	0		7
Soybean aphid (Aphid glycines)
Other PVY Vectors
Bird cherry oat aphid (Rhopalosiphum padi)				25
Corn leaf aphid (Rhopalosiphum maidis)	2		31	3			35	12
English grain aphid (Sitobion avenae)								1
Green bug (Schizaphis graminum)
Potato aphid (Macrosiphum euphorbiae)			1
Sunflower aphid (Aphis helianthi)
Thistle aphid (Lipaphis erysimi)				5
Turnip aphid (Brevicoryne brassicae)
Cotton/melon aphid (Aphis gossypii)			2	1
Pea aphid (Acyrthosiphon pisum)
Cowpea aphid (Aphis craccivora)			22	4			6	8	14
black bean aphid (Aphis fabae)							9
Buckthorn aphid (Aphis nasturii)	5		1	63
Identified non-vectored species				2
Unidentified								1
Total # captured	8	0	57	110	ns	ns	ns	22	14
Total Vectors	8	0	57	108	ns	ns	ns	22	14