North Dakota State University * North Central Research Extension Center
5400 Hwy 83 S, Minot, ND 58701-7645, Voice: (701) 857-7677, FAX: (701) 857-7676
North Central Research Extension Center
NCREC

Jan Knodel, Crop Protection Specialist,  Email: jknodel@ndsuext.nodak.edu

Canola Insect Trapping Network
Bertha Armyworm

                                    Week of

-

June 20 June 27 July 4 July 11 July 18 July 25 Cum.
Total

North Central Region

-- -- -- -- -- --  
Renville County-W. Mohall
Trapper-Louie Voigt
0 10 - 11 1 2 24
Bottineau County-Bottineau
Trapper-Tim Semler
setout 26 8 4 4 2 44
Bottineau County-Kramer
Trapper-Tim Semler
setout 16 10 8 1 0 35
Bottineau County-Willow City
Trapper-Tim Semler
setout 13 14 3 2 1 33
Burke County-Bowbells
Trapper-Dan Folske
setout            
Burke County-Bowbells 2
Trapper-Dan Folske
setout            
Burke County-Powers Lake
Trapper-Dan Folske
setout            
Ward County-NCREC, Minot
Trapper-Jan Knodel
0 5 0 1 0 0 6
Ward County-Kenmare
Trapper-Mike Rose
setout -- 50 11 pulled -- 61
Western Region -- -- -- -- -- -- --
McKenzie County-Arnegard Trapper-Dale Naze 23 4 4 2 0 2 35
Northwest Region -- -- -- -- -- -- --
Divide County-Crosby (north) 
Trapper-Keith Brown
7 40 9 19 4 pulled 79
Williams County-Williston Trapper-Chet Hill -- setout 6 - 2 4 12
Southwest Region -- -- -- -- -- -- --
Slope County-New England
Trapper-Roger Ashley
setout 4 5 1 1 0 11
Dunn County-Dickinson
Trapper-Roger Ashley
setout 3 1 0 1 1 6
Northeast Region -- -- -- -- -- -- --
Cavalier County-Langdon
Trapper-Bryan Hanson
-- -- -- -- 13 6 19
Minnesota               
Pennington County-Thief River Falls                           Trapper-Dave LeGare -- 1 0 0 1 0 2
Roseau                      Trapper-Dave LeGare -- 0 0 0 0 0 0
Grygla                        Trapper-Dave LeGare -- 0 5 0 0 0 5
Interpreting Bertha Armyworm Cumulative Moth Counts

The population of adult bertha armyworms will be monitored during the flight and egg-laying period.  Monitoring is done using pheromone baited traps. The monitoring period extends from about mid-June through July. Each week moths caught in the traps are counted, and data for that week, as well as cumulative moth counts, are entered into the table for the appropriate trapping area. The cumulative total number of moths will continue to rise until the end of the monitoring period. The following table relates the cumulative moth counts with the risk of larval infestation.

 

Cumulative number of Moths  
From To Larval Infestation Risk Level
0 300 Low - Infestations are unlikely to be widespread, but fields should be inspected for signs of insects or damage.
300 900 Uncertain - Infestations may not be widespread, but fields that were particularly attractive to egg-laying females could be infested. Check your fields.
900 1200 Moderate - Canola fields should be sampled regularly for larvae and for evidence of damage.
1200 1500+ High - Canola fields should be sampled frequently for larvae and for evidence of damage.
 
(Other links: Manitoba Bertha Armyworm Factsheet)


Last Updated: Tuesday, August 09, 2005 06:02:33 PM
Published by North Dakota State University
 
Please let us know if you have any comments about or suggestions for this web page. 
jknodel@ndsuext.nodak.edu