Aphid Alert 2000, No. 12, August 27

Update: Summary of virus vector situation through 27 August

Happily, the week ending 30 August saw another sharp decline in aphid flight activity. Captures of green peach aphid averaged 0.20 per trap compared to 0.58 the previous week. Captures of other aphid species that are potential virus vectors also declined to 6.63 per trap compared to 19.17 the previous week. Across all sampling dates, captures of both green peach aphid and other potential virus vectors in 2000 were only 1/5th of what they were in 1999. This should translate into fewer seed lot rejections for virus this winter. However, late season flights of green peach aphid are cause for particular concern. These aphids are mostly coming from commercial potato fields and are likely to be carrying virus. Most seed potato fields have already been killed, but any still remaining should be protected with an effective aphidicide until vine kill is accomplished.

Captures of winged aphids (mean number per trap), 1992-1994 & 1998-2000. Data for Minnesota and North Dakota locations in the Aphid Alert trapping network.

graph showing captures of winged green peach aphid per trap from 1992-1994 and 1998-2000

Fig. 1. Captures of winged green peach aphid per trap.

graph showing captures potential PVY vectors other than green peach aphid per trap from 1992-1994 and 1998-2000

Fig. 2. Captures potential PVY vectors other than green peach aphid per trap.

graph showing captures of winged turnip aphid per trap from 1992-1994 and 1998-2000

Fig. 3. Captures of winged turnip aphid per trap.

graph showing captures of winged small grain aphids per trap from 1992-1994 and 1998-2000

Fig. 4. Captures of winged small grain aphids (i.e., bird cherry-oat aphid, English grain aphid and greenbug) per trap.

graph showing captures of sunflower aphid per trap from 1992-1994 and 1998-2000

Fig. 5. Captures of sunflower aphid per trap.

graph showing captures of other potential PVY vectors per trapfrom 1992-1994 and 1998-2000

Fig. 6. Captures of other potential PVY vectors (including potato aphid, corn leaf aphid, thistle aphid, and others) per trap.

 

 

Aphid captures per trap by location for week ending 27 August

Minnesota

Minnesota Baker
28 August
Climax
28 August
Crookston
30 August
Gully
28 August
Hollandale
No data
Karlstad
28 August
  Aphids per trap per week
Species PLRV/PVY vectors  
green peach aphid   1 (14.3) 1 (2.5)      
potato aphid            
  PVY vectors
bird cherry-oat aphid            
corn leaf aphid 6 (66.7) 3 (42.() 25 (62.5) 4 (18.2)    
English grain aphid            
greenbug            
sunflower aphid            
thistle aphid       2 (9.1)    
turnip aphid   2 (28.6) 3 (7.5) 4 (18,2)    
Other PVY vectors       2 (9.1)    
  Non-vectors and unidentified
non-vectors            
unidentified 3 (33.3) 1 (14.3) 5 (12.5) 8 (36.4)    
Totals 9 7 40 27 No data 1

Minnesota

Minnesota Little Falls
No data
Barnesville
28 August
Rice
No data
Rosemount
28 August
Thief River
No data
Williams
28 August
  Aphids per trap per week
Aphid species PLRV/PVY vectors
green peach aphid       4 (2.6)    
potato aphid            
  PVY vectors
bird cherry-oat aphid       7 (4.5)   1 (7.7)
corn leaf aphid   2 (33.3)   44 (28.2)   5 (38.5)
English grain aphid       1 (0.6)    
greenbug            
sunflower aphid            
thistle aphid   1 (16.7)       2 (15.4)
turnip aphid       3 (1.9)   4 (30.8)
Other PVY vectors       85 (54.5)    
  Non-vectors and unidentified
non-vectors   1 (16.7)        
unidentified   2 (33.3)   12 (7.7)   1 (7.7)
Totals No data 6 No data 156 No data 13

North Dakota

North Dakota Cando
24 August
Hoople
24 August
Linton
28 August
Mandan
28 August
Minot
28 August
Rolette
24 August
Walhalla
24 August
  Aphids per trap per week
Aphid species PLRV/PVY vectors
green peach aphid         1 (3.5) 2 (14.3) 1 (8.3)
potato aphid       1 (1.4)    
PVY vectors
bird cherry-oat aphid     2 (5.3)   3 (10.3)  
corn leaf aphid 1 (33.3)   19 (50) 38 (52.9) 5 (17.2) 3 (21.4) 2 (16.7)
English grain aphid         2 (6.9) 1 (7.1)
greenbug            
sunflower aphid     5 (13.2) 22 (30.6) 7 (24.1) 3 (21.4)
thistle aphid         1 (3.5) 2 (14.3) 7 (58.3)
turnip aphid 1 (33.3) 3 (100) 1 (2.6)   8 (27.6) 1 (7.1) 2 (16.7)
other PVY vectors     2 (5.3)   1 (3.5)  
Non-vectors and unidentified
non-vectors     1 (2.6)   1 (3.5) 1 (7.1)
unidentified     8 (21.1) 11 (15.3)   1 (7.1)
Totals 3 3 38 72 29 14 12

Wisconsin

Wisconsin Antigo
28 August
Rhinelander
28 August
  Aphids per trap per week
Aphid species PLRV/PVY vectors
green peach aphid 1 (16.7)  
potato aphid    
  PVY vectors
bird cherry-oat aphid 2 (33.3)  
corn leaf aphid   7 (100)
English grain aphid    
greenbug    
sunflower aphid    
thistle aphid    
turnip aphid    
other PVY vectors 2 (33.3)  
  Non-vectors and unidentified
non-vectors    
unidentified 1 (16.7)  
Totals 6 7

South Dakota

South Dakota Watertown
28 August
  Aphids per trap per week
Aphid species PLRV/PVY vectors
green peach aphid  
potato aphid  
  PVY vectors
bird cherry-oat aphid 1 (33.3)
corn leaf aphid 2 (66.7)
English grain aphid  
greenbug  
sunflower aphid  
thistle aphid  
turnip aphid  
other PVY vectors  
  Non-vectors and unidentified
non-vectors  
unidentified  
Totals 3

Nebraska

Nebraska Cody
28 August
  Aphids per trap per week
Aphid species PLRV/PVY vectors
green peach aphid  
potato aphid  
  PVY vectors
bird cherry-oat aphid  
corn leaf aphid 34 (100)
English grain aphid  
greenbug  
sunflower aphid  
thistle aphid  
turnip aphid  
other PVY vectors  
  Non-vectors and unidentified
non-vectors  
unidentified  
Totals 34