Here's the catch for the Trapping Period ending Aug 08
(No samples for Stephen MN or Lake of the Woods MN)
(No samples for Stephen MN or Lake of the Woods MN)
Green
peach aphid (one of the most important and most effective vectors of
PVY) was detected in traps from Linton ND, Forest River ND and Sabin MN sites. Corn leaf aphids and English grain aphids in addition to a number of
other vector species were recovered from a number of sites - the
presence of any PVY vector is cause to scout and manage accordingly.
Overall, aphid numbers were similar to or a bit higher than last week.
The number of non-vector aphid
species recovered in most traps was up this week. While these aphids are not involved in the transmission of virus diseases in potatoes, their numbers do indicate aphids are still actively moving in the region. We have begun to recover very low numbers of soybean aphid but their presence and flights remain low. Early August is the
prime period for summer movement of soybean aphid.
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 8/01/2012 – 8/08/2012)
|
|||||||||
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
|
2
|
2
|
||||||
Soybean aphid
(Aphid glycines)
|
1
|
||||||||
OTHER
PVY VECTORS
|
|||||||||
Bird cherry oat aphid (Rhopalosiphum padi)
|
2
|
1
|
1
|
||||||
Corn leaf aphid (Rhopalosiphum maidis)
|
6
|
9
|
7
|
2
|
1
|
||||
English grain aphid (Sitobion avenae)
|
1
|
1
|
5
|
2
|
|||||
Green bug (Schizaphis graminum)
|
|||||||||
Potato aphid (Macrosiphum euphorbiae)
|
1
|
1
|
|||||||
Sunflower aphid (Aphis helianthi)
|
2
|
||||||||
Thistle aphid (Lipaphis erysimi) |
|||||||||
Turnip aphid (Brevicoryne brassicae)
|
|||||||||
Cotton/melon aphid (Aphis gossypii)
|
1
|
1
|
|||||||
Pea aphid (Acyrthosiphon pisum)
|
1
|
||||||||
Cowpea aphid (Aphis craccivora)
|
1
|
||||||||
black bean aphid (Aphis fabae)
|
|||||||||
Buckthorn aphid (Aphis nasturii)
|
1
|
6
|
|||||||
Identified
non-vectored species
|
1
|
1
|
3
|
63
|
10
|
1
|
|||
Unidentified
|
1
|
||||||||
Total # captured
|
11
|
11
|
15
|
0
|
77
|
0
|
21
|
4
|
1
|
Total Verctors
|
10
|
10
|
12
|
0
|
14
|
0
|
11
|
3
|
1
|
