Aphid Alert 1999, No. 8, August 4

Summer 1999: Aphid trapping data

Results reported in this issue of Aphid Alert are total captures of winged aphids and species identifications for the following locations and sampling interval end-dates. Data for missing locations will be incorporated into this week's issue of the newsletter as the data becomes available.

Figure 1 (below). Mean number of winged green peach aphid captured per trap across all locations reported, 1998 data (blue line) and 1999 data (maroon line). These data are also available in table format (Table 1).

graph showing captures of winged green peach aphids per trap from 1998 and 1999 year to date

Figure 2 (below). Mean number of winged aphids of species known to be capable of transmitting PVY (exclusive of green peach aphid) captured per trap across all locations reported, 1998 data (blue line) and 1999 data (maroon line). These data are also available in table format (Table 1).

graph showing captures of PVY vectors other than green peach aphids per trap from 1998 and 1999 year to date

Summary of observations for week ending 3 August

The number of green peach aphids captured in our traps increased sharply during the past week. Numbers of this species have been consistently higher throughout 1999 than on comparable dates in 1998. Last week's green peach aphid captures were double that of the previous year on the same date. None of the green peach aphids tested to date (those captured through 27 Jul) have tested positive for PVY or PLRV, but the high numbers that are present are reason for concern. The other aphid species that are potential vectors of PVY remain at densities very comparable to what we observed in 1998. Numbers of these aphids are also increasing rapidly and can be expected to peak in the next week or two. We consider the risk of virus spread to be high at this time.

We maintain a list of e-mail addresses to facilitate communication with those of you interested in receiving updates about this research or any resulting advisories sooner than this information can be delivered by mail or even before it is posted on the WWW. If you wish your name added to receive such messages please send us an e-mail at radcl001@umn.edu. In the message, write "Aphid Alert subscribe."

Errors: If you find errors, typographic or factual, we would appreciate having them called to our attention so they can be corrected. Phone: Robert Suranyi (218) 773-3346 or Ted Radcliffe (612) 624-773 or send an e-mail to radcl001@umn.edu.

 

Results

Minnesota: Baker, Climax, Gully, Hollandale, Karlstad, Little Falls, Morris, Williams
North Dakota: Cando, Hoople, Linton, Mandan, Rolette, Walhalla

Baker, MN, week ending 2 August

  Aphid species # captured % of total capture
PLRV/PVY vectors green peach aphid 8 10.3
  potato aphid
   
PVY vectors bird cherry-oat aphid 4 5.1
  corn leaf aphid 4 5.1
  English grain aphid 1 1.3
  greenbug
  sunflower aphid
  thistle aphid 13 16.7
  turnip aphid 32 41
   
Identified non-vector species   7 9
   
Unidentified   9 11.5
   
  Total 78

back to top

Climax, MN, week ending 2 August

  Aphid species # captured * % of total capture
PLRV/PVY vectors green peach aphid 7 (13) 4.3
  potato aphid
   
PVY vectors bird cherry-oat aphid 6 (11) 3.7
  corn leaf aphid 5 (5) 1.9
  English grain aphid 1 (2) 0.6
  greenbug
  sunflower aphid 58 (104) 35.8
  thistle aphid 10 (18) 6.2
  turnip aphid 63 (113) 38.9
   
Identified non-vector species   5 (9) 3.1
   
Unidentified   9 (16) 5.6
   
  Sorted / Total * 162 / 290

*Actual numbers in sorted subsample (projected numbers in total collection)

back to top

Gully, MN, week ending 2 August

  Aphid species # captured % of total capture
PLRV/PVY vectors green peach aphid
  potato aphid 1 0.9
   
PVY vectors bird cherry-oat aphid
  corn leaf aphid 24 20.7
  English grain aphid 2 1.7
  greenbug
  sunflower aphid 12 10.3
  thistle aphid 2 1.7
  turnip aphid 54 46.6
   
Identified non-vector species   10 8.6
   
Unidentified   11 9.5
   
  Total 116

back to top

Hollandale, MN, week ending 3 August

  Aphid species # captured % of total capture
PLRV/PVY vectors green peach aphid 1 2.1
  potato aphid
   
PVY vectors bird cherry-oat aphid 3 6.4
  corn leaf aphid 27 57.4
  English grain aphid 1 2.1
  greenbug
  sunflower aphid
  thistle aphid 1 2.1
  turnip aphid
   
Identified non-vector species   7 14.9
   
Unidentified   7 14.9
   
  Total 47

back to top

Karlstad, MN, week ending 3 August

  Aphid species # captured * % of total capture
PLRV/PVY vectors green peach aphid 9 (11) 5.9
  potato aphid 2 (3) 1.3
   
PVY vectors bird cherry-oat aphid 6 (8) 3.9
  corn leaf aphid 6 (8) 3.9
  English grain aphid
  greenbug
  sunflower aphid 47 (59) 6.9
  thistle aphid 11 (14) 13.8
  turnip aphid 62 (78) 45.7
   
Identified non-vector species   3 (4) 2
   
Unidentified   6 (8) 17.2
   
  Sorted / Total * 152 / 191

*Actual numbers in sorted subsample (projected numbers in total collection)

back to top

Little Falls, MN, week ending 2 August

Data not available

back to top

Morris, MN, week ending 2 August

  Aphid species # captured % of total capture
PLRV/PVY vectors green peach aphid 2 10.5
  potato aphid
   
PVY vectors bird cherry-oat aphid
  corn leaf aphid 5 26.3
  English grain aphid      
  greenbug
  sunflower aphid
  thistle aphid 2 10.5
  turnip aphid 7 36.8
   
Identified non-vector species   1 5.3
   
Unidentified   2 10.5
   
  Total 19

back to top

Williams, MN, week ending 3 August

  Aphid species # captured % of total capture
PLRV/PVY vectors green peach aphid 2 1.3
  potato aphid
   
PVY vectors bird cherry-oat aphid 7 4.7
  corn leaf aphid 50 33.3
  English grain aphid 2 1.3
  greenbug
  sunflower aphid 47 31.3
  thistle aphid 7 4.7
  turnip aphid 16 10.7
   
Identified non-vector species   6 4
   
Unidentified   13 8.7
   
  Total 150

back to top

Cando, ND, week ending 30 July

  Aphid species # captured % of total capture
PLRV/PVY vectors green peach aphid 2 4.3
  potato aphid 3 6.5
   
PVY vectors bird cherry-oat aphid 5 10.9
  corn leaf aphid 10 21.7
  English grain aphid 1 2.2
  greenbug
  sunflower aphid
  thistle aphid 9 19.6
  turnip aphid 9 19.6
   
Identified non-vector species   4 8.7
   
Unidentified   3 6.5
   
  Total 46

back to top

Hoople, ND, week ending 30 July

  Aphid species # captured % of total capture
PLRV/PVY vectors green peach aphid 8 10.1
  potato aphid
   
PVY vectors bird cherry-oat aphid 6 7.6
  corn leaf aphid 3 3.8
  English grain aphid
  greenbug
  sunflower aphid 3 3.8
  thistle aphid 8 10.1
  turnip aphid 26 32.9
   
Identified non-vector species   7 8.9
   
Unidentified   18 22.8
   
  Total 79

back to top

Linton, ND, week ending 1 August

  Aphid species # captured * % of total capture
PLRV/PVY vectors green peach aphid 4 (9) 2
  potato aphid
   
PVY vectors bird cherry-oat aphid
  corn leaf aphid 48 (106) 23.4
  English grain aphid
  greenbug
  sunflower aphid 13 (29) 6.3
  thistle aphid 1 (2) 0.5
  turnip aphid 129 (285) 62.9
   
Identified non-vector species   1 (2) 0.5
   
Unidentified   9 (20) 4.4
   
  Sorted / Total * 205 / 453

*Actual numbers in sorted subsample (projected numbers in total collection)

back to top

Mandan, ND, week ending 1 August

  Aphid species # captured * % of total capture
PLRV/PVY vectors green peach aphid 11 (27) 4.7
  potato aphid 2 (5) 0.9
   
PVY vectors bird cherry-oat aphid 4 (10) 1.7
  corn leaf aphid 2 (5) 0.9
  English grain aphid 1 (2) 0.4
  greenbug
  sunflower aphid 14 (34) 6
  thistle aphid 7 (17) 3
  turnip aphid 177 (429) 75.6
   
Identified non-vector species   6 (15) 2.6
   
Unidentified   10 (24) 4.3
   
  Sorted / Total * 234 / 567

*Actual numbers in sorted subsample (projected numbers in total collection)

back to top

Rolette, week ending 30 July

  Aphid species # captured % of total capture
PLRV/PVY vectors green peach aphid      
  potato aphid 2 9.1
                
PVY vectors bird cherry-oat aphid 9 40.9
  corn leaf aphid         
  English grain aphid        
  greenbug   
  sunflower aphid      
  thistle aphid      
  turnip aphid 6 27.3
               
Identified non-vector species   1 4.5
         
Unidentified   4 18.2
         
  Total 22   

back to top

Walhalla, ND, week ending 29 July

  Aphid species # captured % of total capture
PLRV/PVY vectors green peach aphid 5 5.7
  potato aphid 2 4.5
        
PVY vectors bird cherry-oat aphid 3 3.4
  corn leaf aphid 5 5.7
  English grain aphid 1 1.1
  greenbug             
  sunflower aphid 1 1.1
  thistle aphid 11 12.5
  turnip aphid 31 35.2
         
Identified non-vector species   9 10.2
             
Unidentified   18 20.5
             
  Total 88

back to top