Friday, 6 October 2017

Winter Update (Oct 2, 2017; Wk 22) - True armyworm

Earlier this summer (Week 14), the true armyworm (Lepidoptera: Noctuidae: Mythimna unipunctawas reported on the lower west coast and a summary was provided by Tracy Hueppelsheuser (BC Ministry of Agriculture).

Tracy kindly provided an update to the situation.... The initial true armyworm damage reported earlier did not relent and a second generation of voracious larvae continued to cause damage in late August through to late September in southwestern British Columbia.  In addition to Vancouver Island (hit a second time), true armyworm larvae showed up south of Abbotsford, Sumas, Matsqui, Dereoche, as well as east through Chilliwack (Greendale, Rosedale), and west all the way to Delta and Westham Island.  The outbreak resulted in damage to grass fields and even corn was defoliated and cobs damaged!  

True armyworm pupae were observed mid-September and moths are expected over the next while in lower BC.  A third generation is anticipated but is not expected to cause as much damage owing to the cooler nights (~8°C) which should slow insect development and feeding.  Parasitism was noted which is good news in terms of natural enemies responding to the outbreak.  Also, lots of bird feeding activity has been observed although the birds' seeking and feeding activities have also damaged grass fields!

The outbreak of true armyworm in lower BC appears to be part of a larger outbreak that has similarly afflicted western Oregon and Washington this year.  

Find more information on true armyworms in the NEW Cutworm Field Guide, free and downloadable in 2017!

Screenshots of true armyworm from the Cutworm Field guide are also shown below:

Monday, 2 October 2017

Winter Update (Oct 2, 2017; Wk 22) - 2017 Pea leaf weevil distribution map for SK

The 2017 Saskatchewan Pea leaf weevil distribution map was recently posted by Saskatchewan Agriculture.  The survey is based on the average number of feeding notches observed per plant (read more about PLW monitoring).  Watch for the November issue of Agriview when the 2017 map below will be posted accompanied by a written summary.  

Participants involved with the survey are thanked for their efforts and the extra sites that produced the 2017 pea leaf weevil map!  

The effort revealed a marked expansion in distribution within Saskatchewan in 2017 compared to 2016!

More information on pea leaf weevil can be accessed by reviewing Week 6 of the Weekly Update! 

Remember - a NEWLY UPDATED PPMN monitoring protocol is available!  Also refer to the pea leaf weevil page within the "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide" - both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 by Carcamo and Vankosky in Prairie Soils and Crops.