Diamondback Moth Monitoring Program in Manitoba - 2017

 

Diamondback moth does not overwinter well in the Canadian prairie provinces, but large numbers can potentially blow in. If conditions are favorable for their survival and reproduction when they arrive, and if natural enemies do not limit population establishment, populations can increase.

Pheromone-baited traps (Fig. 1), which attract the male moths, are established for a 6-8 week period from early-May until late-June to detect the arrival of populations of diamondback moth early in the season. The cumulative counts from the traps can not predict what levels of larvae will be, but can be used to determine regions of the province where increased attention for diamondback moth is recommended when scouting fields.

                                                                                      
Fig. 1. Trap for diamondback moth                                 Fig. 2. Diamondback moth on insert of trap

 Summary

Very low levels of moths were caught in traps in May and early-June. The highest cumulative trap count on June 4 was 19.  Some higher levels of moths were caught in some traps from June 4th to 17th. Highest trap counts have been in the Northwest and Interlake, and the region with the lowest counts is the Southwest.


Table 1. Highest cumulative trap counts per region over the trapping period (May 1 to June 24, 2017):

 
Location Count
Northwest
  Minitonas 180
  The Pas 93
  The Pas 69
Southwest
  Basswood 13
  Franklin 11
  Austin 11
Central
  St. Adolphe 83
  Ste. Agathe 60
  Morris  46
  Lowe Farm 43
Eastern
  Whitemouth 75
  Lockport 63
  Lac du Bonnet 34
Interlake
  Teulon 107
  Fisher Branch 63
  Grahamdale 46
  Gimli 22
 
 
Presence of Larvae and Pupae: By June 13th larvae of diamondback moth were at noticeable levels in many fields in Central Manitoba, and some pupae were detected as well.
 

Guidelines for monitoring larvae of diamondback moth can be found at: https://www.gov.mb.ca/agriculture/crops/insects/diamondback-moth.html

                                                        
                                            Fig. 3. Diamondback moth pupa (left) and larva (right).