Weekly Update

Jennifer Otani, Ross Weiss, David Giffen, Erl Svendsen and Owen Olfert
Categories
Week 4

The Weekly Update received additional data and was updated on Friday.  Please be sure to read over the updated sections for Week 4 (May 25, 2016) which include:

  • Updated Weather Synopsis
  • Updated Pea Leaf Weevil Status
  • Updated Grasshopper Model Outputs (embronic development and progression of hatch)
  • Updated Cereal Leaf Beetle Model Outputs
  • Wheat Midge Model Outputs
  • Lygus Model Outputs

To read the entire Weekly Update for Week 4, you can either:
  1. Search the Blog for “Week 4” or,
  2. Under the LABEL menu on the right side of your screen, click “Week 4 (May 25, 2016)” so the Blog sorts all Posts.

The updated and downloadable PDF of the Weekly Update for Week 4 is available here and the hyperlink within the original Post has also been updated.

Weekly Update – Greetings!

Jennifer Otani, Hector Carcamo, David Giffen, Ross Weiss, Scott Hartley and Owen Olfert
Categories
Week 4

A downloadable PDF version of the complete Weekly Update for Week 4 (May 25, 2016) can be accessed here.

Subscribe to the Blog by following the instructions posted here!  You can receive automatic updates in your inbox through the growing season.


Questions or problems accessing the contents of this Weekly Update?  Please e-mail either Dr. Owen Olfert or Jennifer Otani.  Past “Weekly Updates” are very kindly archived to the Western Forum website by webmaster, Dr. Kelly Turkington.  

Wind Trajectories

Ross Weiss, Owen Olfert, Serge Trudel and prairiepest_admin
Categories
Week 4

THE WEEK OF MAY 24, 2016:  Wind trajectory data processing by AAFC-Saskatoon Staff began in April.  Reverse Trajectories track arriving air masses back to their point of origin while Forward Trajectories predict favourable winds expected to arrive across the Canadian Prairies for the week of May 24, 2016:


Reverse trajectories (RT) – Mexico and southwest USA
Compared to 2015, the number of reverse trajectories crossing the prairies is greater in 2016.  Since April 1, there have been 18 prairie locations that have had RT’s originating from southwest USA. This compares with 12 for the same time last year. 

Reverse Trajectories originating from Mexico and southwest USA between April 1-May 24, 2016:





…..Compared to last year!






Diamondback moth

Jennifer Otani
Categories
Week 4

Diamondback moth (Plutellidae: Plutella xylostella) – Pheromone traps attracting male Diamondback moths (Fig. 1) have been deployed across the prairies.  

Figure 1. Diamondback moth.



Counts will be reported by the provincial staff in Saskatchewan.  Manitoba Agriculture and Rural Initiatives posted low DBM counts which can be reviewed within their second Insect Report.  Alberta Agriculture and Forestry has a live 2016 map reporting Diamondback moth pheromone trap interceptions.  A copy of the map (retrieved May 25, 2016) is below for reference.





Larval Monitoring:
Once the diamondback moth is present in the area, it is important to monitor individual canola fields for larvae.  Remove the plants in an area measuring 0.1 m2 (about 12″ square), beat them on to a clean surface and count the number of larvae (Fig. 2) dislodged from the plant. Repeat this procedure at least in five locations in the field to get an accurate count.

Figure 2. Diamondback larva measuring ~8mm long.
Note brown head capsule and forked appearance of prolegs on posterior.




Figure 3. Diamondback moth pupa within silken cocoon.

Economic threshold for diamondback moth in canola at the advanced pod stage is 20 to 30 larvae/ 0.1 m2 (approximately 2-3 larvae per plant).  Economic thresholds for canola or mustard in the early flowering stage are not available. However, insecticide applications are likely required at larval densities of 10 to 15 larvae/ 0.1 m2 (approximately 1-2 larvae per plant).


Biological and monitoring information for DBM is posted by Manitoba Agriculture, Food and Rural DevelopmentSaskatchewan AgricultureAlberta Agriculture and Forestry, and the Prairie Pest Monitoring Network.  

More information about Diamondback moths can be found by accessing the pages from the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Field Guide”.  View ONLY the Diamondback moth page but remember the guide is available as a free downloadable document as both an English-enhanced or French-enhanced version.


Weekly Update – Cutworms

Jennifer Otani, Scott Meers and John Gavloski
Categories
Week 4

Reminder – Cutworms (Noctuidae) – Keep an eye on fields that are “slow” to emerge, are missing rows, include wilting or yellowing plants, have bare patches, or appear highly attractive to birds – these are areas warranting a closer look.  Plan to follow-up by walking these areas later in the day when some cutworm species move above-ground to feed.  Start to dig below the soil surface (1-5 cm deep) near the base of a symptomatic plant or the adjacent healthy plant.  If the plant is well-established, check within the crown in addition to the adjacent soil.  The culprits could be wireworms or cutworms.  

Several species of cutworms  can be present in fields.  They range in colour from shiny opaque, to tan, to brownish-red with chevron patterning.  Cutworm biology, species information, plus monitoring recommendations are available in the Prairie Pest Monitoring Network’s Cutworm Monitoring Protocol.  Also refer to Manitoba Agriculture and Rural Initiatives cutworm fact sheet which includes action and economic thresholds for cutworms in several crops. 

More information about cutworms can be found by accessing the pages from the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Field Guide”.  View an excerpt of ONLY the Cutworm pages from the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide”.  The guide is available as a free downloadable document as both an English-enhanced or French-enhanced version.



For Manitobans….The most recent Insect Update includes great photos of dingy and redbacked cutworms plus monitoring tips which include how to discern these two species from one another.

For Albertans….. Cutworms have been reported throughout the province the past week!  If you find cutworms, please consider using the Alberta Pest Surveillance Network’s “2016 Cutworm Reporting Tool”.  Once data entry occurs, your growers can view the live 2016 cutworm map.

A screen shot of the live map has been retrieved (25May2016) below for your reference.


Weekly Update – Pea leaf weevil update

Hector Carcamo, Scott Hartley and Jennifer Otani
Categories
Week 4

Pea leaf weevil monitoring is underway in Alberta and Saskatchewan.  Despite the common name, Sitona lineolatus, will feed on several species of legumes including faba beans, seedling alfalfa, dry beans and of course peas!


Thanks to Dr. Hector Carcamo (AAFC-Lethbridge) for the following update (24May2016):
A mild winter and a very warm and early spring have contributed to what looks like the worst outbreak of pea leaf weevil in southern Alberta. Weevil densities appear to be high enough to be threatening stand establishment of peas this year.


Normally, adult feeding damage has little consequence whereas the main concern is related to larval feeding damage to nitrogen fixing nodules.  That’s NOT the case this year – several growers are spraying for PLW in peas because small seedlings are suffering very high defoliation resulting in stand reductions – something seen previously only in seedling alfalfa stands. Additionally, this year some stands treated with a registered neonicotinoid insecticide have required foliar spraying; the insecticide seed treatment may not provide sufficient protection when weevil densities are extremely high.  Growers hoping to prevent yield losses may consider supplementing with nitrogen during the seedling stage but be cautious – the economic returns should be carefully considered, given input prices.  Finally, be mindful that PLW adults emerge from overwintering over several weeks so sprayed fields may be repeatedly invaded – continued monitoring is a necessity!

Weevils have natural enemies such as ground dwelling beetles that feed on their eggs. The best way to protect natural enemies is to avoid foliar applications of insecticide unless damage reaches the economic threshold of 30% of seedlings with damage on the clam leaf (i.e., assess using 10 transects of 10 seedlings, half near the edge and half inside the field).


Thanks to Scott Hartley (Sask Ag) who noted (25May2016) that PLW surveying is underway in the southwestern Saskatchewan (i.e., as far north as Kindersley / Outlook and east to mid-way between Swift Current and Moose Jaw).   Preliminary reports include  high levels of feeding in several areas in the southwest.  Crops were generally seeded earlier this year than in the past few years. Seed treatments are considered the best control for the pea leaf weevil but, if 30% of plants are showing damage, a foliar insecticide could be required but this strategy is not as consistently effective as a seed treatment. Foliar insecticide may be necessary if plants are very young and therefore more vulnerable to heavy feeding pressure. Remember plants can outgrow PLW damage once they are past the 6th node stage.



Also refer to previous PLW posts for additional information!
Weekly Update from May 18, 2016
Insect of the Week from 2015
Pea leaf weevil in Central Alberta in 2015
The PPMN’s Pea leaf weevil monitoring protocol

Weekly Update – Alfalfa weevil

Ross Weiss, Owen Olfert, David Giffen and Julie Soroka
Categories
Week 4

Alfalfa Weevil (Hypera postica) – The larval stage of this weevil feeds on alfalfa leaves in a manner that characterizes the pest as a “skeletonizer”.  The green larva featuring a dorsal, white line down the length of its body has a dark brown head capsule and will grow to 9mm long.  Alfalfa growers are encouraged to check the Alfalfa Weevil Fact Sheet prepared by Dr. Julie Soroka (AAFC-Saskatoon).


Degree-day maps of base 9°C are now being produced by Soroka, Olfert, and Giffen (2016) using the Harcourt/North Dakota models.  The aim or the modelling is to predict the development of Alfalfa weevil (Hypera postica) across the prairies and to help growers time their in-field scouting as second-instar larvae are predicted to occur.  Compare the following predicted development stages and degree-day values copied below (Soroka 2015) to the map below.



This week, alfalfa growers situated within ANY shade of purple should prioritize scouting for second instar larvae and compare it to the action threshold for alfalfa weevil which varies according to end use and crop stage.  


Weekly Update – Predicted Bertha Armyworm Development

Ross Weiss, Owen Olfert, David Giffen and Erl Svendsen
Categories
Week 4

Bertha armyworm (Lepidoptera: Mamestra configurata– Bertha armyworm (BAW) pupal development is progressing well, particularly across AB.  Pheromone traps should be deployed in areas highlighted yellow in the map below.





Those monitoring BAW pheromone traps may want to compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture below:


Weekly Update – Cereal leaf beetle predictions

Ross Weiss, Owen Olfert, David Giffen and Erl Svendsen
Categories
Week 4

Cereal leaf beetle (Oulema melanopus) – The following are results from the bioclimate model which predicts cereal leaf beetle (CLB) populations.




As of May 23, 2016, the CLB model indicated that oviposition is well underway: 

  • In Alberta and western Saskatchewan, development was similar to the previous week.
  • Warmer conditions in eastern Saskatchewan and Manitoba resulted in faster development. 
  • Larval populations are predicted to peak in mid-June across most locations in the southern prairies.

Predicted dates of peak emergence of CLB eggs and larvae:



The following model outputs have been updated this week and reflect the predicted stages of CLB present in fields in relation to its parasitoid, Tetrastichus julis














Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Weekly Update – Predicted Grasshopper Development

Ross Weiss, Owen Olfert, David Giffen and Erl Svendsen
Categories
Week 4

Grasshoppers (Acrididae) – This past week, cooler conditions in Alberta slowed egg development while warmer conditions in Saskatchewan enhanced development. 


For the week of May 23, 2016, the predicted mean embryological development was 85% compared to 75% for the previous week. These results suggest that grasshopper hatch will rapidly progress over the next week to ten days



The model predicted that 13% of the hatch is complete (compared to last week’s value of 5%). Peak hatch (approx. 30%) was predicted to occur between Saskatoon and Regina.

Biological and monitoring information related to grasshoppers in field crops is posted by the provinces of ManitobaSaskatchewanAlbertaBritish Columbia and the Prairie Pest Monitoring Network.  Also refer to the grasshopper pages within the new “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.

Weekly Update – Wheat midge

Owen Olfert, Ross Weiss, Erl Svendsen, David Giffen and Jennifer Otani
Categories
Week 4

Wheat Midge (Sitodiplosis mosellana) – Predictive modelling will be used again to help  forecast wheat midge emergence across the Canadian prairies.  The maps below predicts the geographic distribution and corresponding accumulation of heat units necessary for wheat midge to emerge from puparia developing in the soil.  

For the week of May 23, 2016, model runs for Saskatoon SK and Fairview AB presented similar results. Unlike last year when dry soil moisture limited development, soil moisture conditions appear to be suitable for wheat midge development in the soil. Output indicates that larvae should be moving to the soil surface later this week. 









Information related to wheat midge biology and monitoring can be accessed by linking to your provincial fact sheet (Saskatchewan Agriculture or Alberta Agriculture & Forestry).  A review of wheat midge on the Canadian prairies was published by Elliott, Olfert, and Hartley in 2011.

More information about Wheat midge can be found by accessing the pages from the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Field Guide”.  View ONLY the Wheat midge pages but remember the guide is available as a free downloadable document as both an English-enhanced or French-enhanced version.

Provincial Insect Pest Reports

John Gavloski, Scott Meers, Scott Hartley and prairiepest_admin
Categories
Week 4

Provincial entomologists provide insect pest updates throughout the growing season so we have attempted to link to their most recent information: 

– Manitoba’s Insect preview article (May 25, 2016, published by the Manitoba Cooperator).
– Saskatchewan’s Insect Pest Outlook article (April 7, 2016,  published by the Western Producer).
– Watch for Alberta Agriculture and Forestry’s Call of the Land for updates from Scott Meers  (posted on May 19, 2016).


Weekly Update – Crop reports

Scott Meers, Scott Hartley, John Gavloski and prairiepest_admin
Categories
Week 4

Crop reports are produced by:

– Manitoba Agriculture, Rural Development (May 23, 2016)
– Saskatchewan Agriculture Crop Report (May 16, 2016)
– Alberta Agriculture and Forestry (for May 17, 2016)


Reminder – International reports are produced by:

The United States Department of Agriculture’s Crop Progress Report (May 23, 2016)
The European Commission’s Agriculture and Rural Development report on Short-term Outlook for EU Arable Crops, Dairy and Meat Markets (Winter issue).

Weekly Update – Weather Synopsis

Ross Weiss, David Giffen, Owen Olfert and prairiepest_admin
Categories
Week 4

Across the prairies, meteorological conditions were similar to long term average values for May 16-23, 2016. The average temperature was 11.1 °C and was much warmer than the previous seven days (8.7 °C) and was 1 °C warmer than the average temperature.  Temperatures were generally warmer in Manitoba and eastern Saskatchewan than western Saskatchewan and Alberta.


This past week, many Albertan locations reported significant rainfall amounts while minimal amounts were reported for Saskatchewan and Manitoba.  


The map below shows the Accumulated Precipitation the past 7 days (i.e., May 16-23, 2016) which fell as both rain and snow in the west: 


The map below reflects the Accumulated Precipitation for the Growing Season so far for the prairie provinces (i.e., April 1-May 24, 2016):




Compared to last week, soil moisture levels were predicted improve across most of Alberta.  Lower soil moisture values were predicted across most of Saskatchewan.


Again cooler temperatures put newly emerging crops at risk.  The map below shows the Lowest Temperatures the Past 7 Days (May 18-24, 2016) across the prairies:

The map below shows the Highest Temperatures the Past 7 Days (May 18-24, 2016):

The updated growing degree day map (GDD) (Base 5ºC, March 1 – May 23, 2016) is below:





While the growing degree day map (GDD) (Base 10ºC, March 1 – May 23, 2016) is below:



The maps above are all produced by Agriculture and Agri-Food Canada.  Growers may wish to bookmark the AAFC Drought Watch Maps for the growing season.

Weekly Update – Canola scouting chart

Jennifer Otani
Categories
Week 4
We again post our generalized canola scouting chart to aid in-field scouting on the Canadian prairies. The version below contains hyperlinks to help growers learn more about some of our insect pests and how to monitor for them.



Weekly Update – Flea beetles

Jennifer Otani and Julie Soroka
Categories
Week 4

Reminder – Flea Beetles (Chrysomelidae: Phyllotreta species) – Remember, the Action Threshold for flea beetles on canola is 25% of cotyledon leaf area consumed.  Shot-hole feeding is the traditional damage in seedling canola but watch the growing point and stems of seedlings.

Estimating flea beetle feeding damage can be challenging.  Using a visual guide to estimate damage can be helpful.  Canola Watch circulated this article but also use the images (copied below for reference) produced by Dr. J. Soroka (AAFC-Saskatoon)  – take it scouting!

Figure 1. Canola cotyledons with various percentages of leaf area consume owing to flea beetle feeding damage (Photo: Soroka & Underwood, AAFC-Saskatoon).


Figure 2.  Percent leaf area consumed by flea beetles feeding on canola seedlings (Photo: Soroka & Underwood, AAFC-Saskatoon).

Refer to the flea beetle page from the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” as an English-enhanced or French-enhanced version.


Also refer to the previous Flea beetle post on the Blog.



Weekly Update – Pea leaf weevil

Jennifer Otani
Categories
Week 4

Pea leaf weevil (Sitona lineatus) – Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight.  Adults are slender, greyish-brown measuring approximately 5 mm in length (Figure 1).

Figure 1. The pea leaf weevil, Sitona lineatus, measures ~5mm long (Photo: H. Goulet).



The pea leaf weevil resembles the sweet clover weevil (Sitona cylindricollis) yet the former is distinguished by three light-coloured stripes extending length-wise down thorax and sometimes the abdomen (Link here for the Pea leaf weevil monitoring protocol with photos of related weevils).  All species of Sitona, including the pea leaf weevil, have a short snout.


Adults will feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge (Figure 2).  Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.

Figure 2. Feeding notches on clam leaf of pea plant resulting from pea leaf weevil (Photo: L. Dosdall).

Weekly Update – Lygus bugs

Ross Weiss, Owen Olfert, Erl Svendsen and David Giffen
Categories
Week 4

Lygus bugs (Lygus spp.) – Model runs for Lygus suggest that oviposition should begin later this week at Saskatoon and 10-14 days later at Lethbridge.







Information related to Lygus bug biology and monitoring can be accessed by linking to your provincial fact sheet (Manitoba Agriculture and Rural Initiatives or Alberta Agriculture & Forestry).  

More information about Wheat midge can be found by accessing the pages from the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Field Guide”.  View ONLY the Lygus bug pages, or Alfalfa plant bug, or Superb plant bug pages but remember the guide is available as a free downloadable document as both an English-enhanced or French-enhanced version.

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