Weekly Update (Jun 29, 2017; Wk 09) - Greetings! Otani, Giffen, Svendsen, Olfert

Greetings!

This week AAFC Staff are out surveying so the Weekly Update will be released in segments.  Please access the series of Posts for Week 9 (Jun 29, 2017) to reach the most up-to-date information.   

Remember, if we're in the field, you should be too!

Questions or problems accessing the contents of this Weekly Update?  Please e-mail either Dr. Owen Olfert or Jennifer Otani.  Past “Weekly Updates” can be accessed on our Weekly Update page.

Subscribe to the Blog by following these easy steps!

Weekly Update (Jun 29, 2017; Wk 09) - Weather Synopsis

Weather synopsis – Our AAFC Staff are busy surveying this week so be sure to check back for updates!

Precipitation for the growing season is presented below (April 1-June 27, 2017) followed by the precipitation expressed as Percent of Normal for the same period.

Over the past seven days, the greatest precipitation fell in northern growing areas along areas typically grouped as Boreal Plains (June 21-27, 2017).  Southern Alberta, southeast Saskatchewan and southwest Manitoba received the lowest amounts of precipitation over the same period.

The lowest temperatures across the prairies over the past seven days (June 21-27, 2017) are mapped below.  Although there was little chance of frost, much of the prairies recorded lows ranging from 0-4°C.

In contrast, the highest temperatures recorded over the past seven days (June 21-27, 2017) are presented below.  The field crops in some of these areas endured daily fluctuations of 20-25°C.

The updated growing degree day map (GDD) (Base 5ºC, March 1 – June 25, 2017) is below:

While the growing degree day map (GDD) (Base 10ºC, March 1 – June 25, 2017) 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 (Jun 29, 2017; Wk 09) - Predicted Bertha Armyworm Development

Bertha armyworm (Lepidoptera: Mamestra configurata) - Bertha armyworm should be in the adult stage across the prairies this week.  The map illustrates predicted appearance of adults (percent of the population) across the southern prairies.

For those monitoring BAW pheromone traps, compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture:

Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta and the Prairie Pest Monitoring Network.  Also refer to the bertha armyworm 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 (Jun 29, 2017; Wk 09) - Wheat midge

Wheat Midge (Sitodiplosis mosellana) – Reminder - The previous Insect of the Week (Week 7) features wheat midge!  

Simulation modelling is used to predict wheat midge emergence across the Canadian prairies.  The model has not changed significantly from last week. The map below predicts the geographic distribution and corresponding accumulation of heat units necessary for wheat midge to emerge from puparia developing in the soil.  

Monitoring:
When monitoring wheat fields, pay attention to the synchrony between flying midge and anthesis.  

In-field monitoring for wheat midge should be carried out in the evening (preferably after 8:30 pm or later) when the female midges are most active. On warm (at least 15ºC), calm evenings, the midge can be observed in the field, laying their eggs on the wheat heads (photographed by AAFC-Beav-S. Dufton & A. Jorgensen below). Midge populations can be estimated by counting the number of adults present on 4 or 5 wheat heads. Inspect the field daily in at least 3 or 4 locations during the evening.

REMEMBER that in-field counts of wheat midge per head remain the basis of economic threshold decision.  Also remember that the parasitoid, Macroglenes penetrans (photographed by AAFC-Beav-S. Dufton below), is actively searching for wheat midge at the same time.  Preserve this parasitoid whenever possible and remember your insecticide control options for wheat midge also kill these beneficial insects which help reduce midge populations.

Economic Thresholds for Wheat Midge:

a) To maintain optimum grade: 1 adult midge per 8 to 10 wheat heads during the susceptible stage.

b) For yield only: 1 adult midge per 4 to 5 heads. At this level of infestation, wheat yields will be reduced by approximately 15% if the midge is not controlled.

Inspect the developing kernels for the presence of larvae and the larval damage. 

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.  

NEW - Alberta Agriculture and Forestry has also released a YouTube video describing in-field monitoring for wheat midge this week.  

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.

Weekly Update (Jun 29, 2017; Wk 09) - White grubs in field crops (Floate)

Scarabaeidae – Reminder - Each June brings scattered reports across the Prairies of white grubs associated with crop damage.  In fact, several species of Aphodius, Phyllophaga, Polyphylla or even small Aetenius produce larvae described as "white grubs".  

Recently, crop damage reports have been associated with a grub identified as the larvae of the beetle Aphodius distinctus (see below). This common beetle is not known to be a pest, but there is an ongoing effort to gather information to develop a ‘pest’ profile.  Additional information is online at Top Crop Manager. Please send reports of this insect and associated information to Dr. Kevin Floate (Agriculture and Agri-Food Canada, Lethbridge, AB).

Weekly Update (Jun 29, 2017; Wk 09) - Painted Lady Butterfly

Painted Lady Butterflies (Lepidoptera: Vanessa cardui) - Back on Week 6, we posted information and links related to the adult.  

UPDATE - This week, Alberta Agriculture & Forestry reminded their network of cooperators to watch for V. cardui larvae because the species has a broad host range and can feed on soybean (Action threshold=>25% defoliation), sunflowers, borage and dry beans in addition to several species of thistles (including Canada thistle) and mallow. 

In addition to the Week 6 information linking to the Butterflies of Canada entry for Vanessa cardui, the Butterflies and Moths of North America website tracks confirmed sightings of V. cardui (screenshot provided below).

The Butterflies and Moths of North America website also includes some verified photos of larvae to compare to when scouting.  Here's screenshot below of the photo provided by T. Stout to hasten the need to link to this valuable resource!

Weekly Update (Jun 29, 2017; Wk 09) - Monarch migration

We again track the migration of the Monarch butterflies as they move north by checking the 2017 Monarch Migration Map!  A screen shot of the map has been placed below as an example (retrieved 22Jun2017) but follow the hyperlink to check the interactive map!  They've migrated into southern Manitoba (various), southeast Saskatchewan (near Rhein), and now Alberta (near Sylvan Lake)! 

Weekly Update (Jun 29, 2017; Wk 09) - Previous Posts

The following is a list of 2017 Posts - click to review:

Alfalfa weevil (Week 7)

Brood X Cicadas

Cabbage seedpod weevil (Week 8)
Canola scouting chart
Cereal leaf beetle
Crickets with your popcorn
Crop protection guides
Crop reports (Week 8)
Cutworms

Diamondback moth

Flax scouting chart
Flea beetles

Grasshopper development (Week 8)

Iceberg reports

Lily leaf beetle

Pea leaf weevil
PMRA Pesticide Label Mobile App
Provincial Insect Pest Reports (Week 8)

Nysius niger (Week 8)

Ticks and Lyme disease

Weather radar

Wind trajectories

Insect of the Week (June 26, 2017) - Cereal aphids

This week’s Insect of the Week is the group of aphids known as cereal aphids. These aphids include the corn leaf aphid, the English grain aphid, the oat-birdcherry aphid and the Russian wheat aphid. They feed on cereal crops and are vectors of viruses, causing lower crop quality and yield. There are several natural enemies of cereal aphids, including various species of wasps and beetles. 

For more information on cereal aphids, see our Insect of the Week page. 

English grain aphid - adult, nymph (Tyler Wist, AAFC)

Remember the NEW Cutworm Field Guide is free and downloadable in 2017!

Weekly Update (Jun 22, 2017; Wk 08) - Greetings! Otani, Giffen, Svendsen, Olfert

Greetings!

Access the complete Weekly Update either as a series of Posts for Week 8 (Jun 22, 2017) OR a downloadable PDF version.

Questions or problems accessing the contents of this Weekly Update?  Please e-mail either Dr. Owen Olfert or Jennifer Otani.  Past “Weekly Updates” can be accessed on our Weekly Update page.

Subscribe to the Blog by following these easy steps!

Weekly Update (Jun 22, 2017; Wk 08) - Weather Synopsis

Weather synopsis – This past week our average temperatures were cooler than last week, and 2 - 3°C cooler than long term averages for mid-June (Fig. 1).  The second map presents the 30-day average temperature (Fig. 2).  

Figure 1. Average temperature across the Canadian prairies from June 4-11, 2017.

Figure 2. Average temperature across the Canadian prairies from May 19-June 19, 2017.

Temperature - The seven-day accumulated precipitation was greater than 15 mm with southeast Saskatchewan and southwest Manitoba reporting amounts in excess of 40 mm (Fig. 3).  

Figure 3. Accumulated precipitation across the Canadian prairies from June 11-18, 2017.

Compared to last week, the 30-day rainfall amounts are similar to long term average values for southern Manitoba, southeast Saskatchewan and southwest Alberta (Fig. 4). A large region in south and central Saskatchewan is reporting well below normal precipitation.

Figure 4. Percent of average precipitation from May 20-June 18, 2017.

The following is the accumulated precipitation for the growing season up to June 18, 2017.

The updated growing degree day map (GDD) (Base 5ºC, March 1 – June 18, 2017) is below:

While the growing degree day map (GDD) (Base 10ºC, March 1 – June 18, 2017) 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 (Jun 22, 2017; Wk 08) - Alfalfa weevil

Alfalfa Weevil (Hypera postica) – The model output for alfalfa weevil is not signficantly different that that posted last week for June 22nd (Week 7).

Alfalfa growers are encouraged to check the Alfalfa Weevil Fact Sheet prepared by Dr. Julie Soroka (AAFC-Saskatoon) and additional information can be accessed by reviewing the Alfalfa Weevil Page extracted from the "Field crop and forage pests and their natural enemies in western Canada - Identification and management field guide" (Philip et al. 2015).  That guide is available in both a free English-enhanced or French-enhanced version.

Weekly Update (Jun 22, 2017; Wk 08) - Predicted Grasshopper Development

Grasshopper Simulation Model Output – Predicted hatch was 71% (52% last week) with 30% of the population in the first instar, 26% second instar, 12% third instar and 2% in the fourth instar. Across the prairies, the mean developmental stage was second instar. The greatest development was predicted to be across southern regions in all three provinces. 

Grasshopper populations near Saskatoon were predicted to be primarily in the second instar this week with the appearance of third and fourth instars. Model output suggests that grasshopper development is slightly ahead of average development. Based on long term meteorological data, populations should be predominantly in the first and second instars with a low number being third instars. This week’s survey (SW of Saskatoon) indicates that most melanopline grasshoppers are already in the second and third numbers.  

Grasshopper Scouting Steps: 

● Measure off a distance of 50 m on the level road surface and mark both starting and finishing points using markers or specific posts on the field margin.

● Starting at one end in either the field or the roadside and walk toward the other end of the 50 m making some disturbance with your feet to encourage any grasshoppers to jump. 

● Grasshoppers that jump/fly through the field of view within a one meter width in front of the observer are counted. 

● A meter stick can be carried as a visual tool to give perspective for a one meter width.  However, after a few stops one can often visualize the necessary width and a meter stick may not be required. Also, a hand-held counter can be useful in counting while the observer counts off the required distance. 

● At the end point the total number of grasshoppers is divided by 50 to give an average per meter. For 100 m, repeat this procedure. 
● Compare counts to the following damage levels associated with pest species of grasshopers:

0-2  per m² - None to very light damage

2-4  per m² - Very light damage

4-8  per m² - Light damage

8-12 per m² - Action threshold in cereals and canola

12-24 per m² - Severe damage 

>24 per m² - Very severe damage

* For lentils at flowering and pod stages, >2 per m² will cause yield loss.

* For flax at boll stages, >2 per m² will cause yield loss.

Reminder:  Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba Agriculture, Food and Rural Development, Saskatchewan Agriculture, Alberta Agriculture and Forestry, the BC Ministry of Agriculture 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" as an English-enhanced or French-enhanced version.

Weekly Update (Jun 22, 2017; Wk 08) - Predicted Bertha Armyworm Development

Bertha armyworm (Lepidoptera: Mamestra configurata) - Bertha armyworm should be in the adult stage across the prairies this week.  The map illustrates predicted appearance of adults (percent of the population) across the southern prairies.

For those monitoring BAW pheromone traps, compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture:

Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta and the Prairie Pest Monitoring Network.  Also refer to the bertha armyworm 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 (Jun 22, 2017; Wk 08) - Wheat midge

Wheat Midge (Sitodiplosis mosellana) – Reminder - The previous Insect of the Week (Week 7) features wheat midge!  

Simulation modelling is used to predict wheat midge emergence across the Canadian prairies.  The model has not changed significantly from last week. The map below predicts the geographic distribution and corresponding accumulation of heat units necessary for wheat midge to emerge from puparia developing in the soil.  

Monitoring:
When monitoring wheat fields, pay attention to the synchrony between flying midge and anthesis.  

In-field monitoring for wheat midge should be carried out in the evening (preferably after 8:30 pm or later) when the female midges are most active. On warm (at least 15ºC), calm evenings, the midge can be observed in the field, laying their eggs on the wheat heads (photographed by AAFC-Beav-S. Dufton & A. Jorgensen below). Midge populations can be estimated by counting the number of adults present on 4 or 5 wheat heads. Inspect the field daily in at least 3 or 4 locations during the evening.

REMEMBER that in-field counts of wheat midge per head remain the basis of economic threshold decision.  Also remember that the parasitoid, Macroglenes penetrans (photographed by AAFC-Beav-S. Dufton below), is actively searching for wheat midge at the same time.  Preserve this parasitoid whenever possible and remember your insecticide control options for wheat midge also kill these beneficial insects which help reduce midge populations.

Economic Thresholds for Wheat Midge:

a) To maintain optimum grade: 1 adult midge per 8 to 10 wheat heads during the susceptible stage.

b) For yield only: 1 adult midge per 4 to 5 heads. At this level of infestation, wheat yields will be reduced by approximately 15% if the midge is not controlled.

Inspect the developing kernels for the presence of larvae and the larval damage. 

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.  

NEW - Alberta Agriculture and Forestry has also released a YouTube video describing in-field monitoring for wheat midge this week.  

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.

Weekly Update (July 22, 2017; Wk 8) - Cabbage seedpod weevil

Cabbage seedpod weevil (Ceutorhynchus obstrictus) -  There is one generation of CSPW per year and the overwintering stage is the adult which is an ash-grey weevil measuring 3-4mm long (Refer to lower left photo).  Adults typically overwinter in soil beneath leaf litter within shelter belts and roadside ditches.

Monitoring:  
 ● Begin sampling when the crop first enters the bud stage and continue through the flowering. 
 ● Sweep-net samples should be taken at ten locations within the field with ten 180° sweeps per location.  
 ● Count the number of weevils at each location. Samples should be taken in the field perimeter as well as throughout the field.  
 ● Adults will invade fields from the margins and if infestations are high in the borders, application of an insecticide to the field margins may be effective in reducing the population to levels below which economic injury will occur.  
 ● An insecticide application is recommended when three to four weevils per sweep are collected and has been shown to be the most effective when canola is in the 10 to 20% bloom stage (2-4 days after flowering starts). 
 ● Consider making insecticide applications late in the day to reduce the impact on pollinators.  Whenever possible, provide advanced warning of intended insecticide applications to commercial beekeepers operating in the vicinity to help protect foraging pollinators.  
 ● High numbers of adults in the fall may indicate the potential for economic infestations the following spring.


Damage: Adult feeding damage to buds is more evident in dry years when canola is unable to compensate for bud loss.  Adults mate following a pollen meal then the female will deposit a single egg through the wall of a developing pod or adjacent to a developing seed within the pod (refer to lower right photo).  Eggs are oval and an opaque white, each measuring ~1mm long.  Typically a single egg is laid per pod although, when CSPW densities are high, two or more eggs may be laid per pod.

There are four larval instar stages of the CSPW and each stage is white and grub-like in appearance ranging up to 5-6mm in length (refer to lower left photo).  The first instar larva feeds on the cuticle on the outside of the pod while the second instar larva bores into the pod, feeding on the developing seeds.  A single larva consumes about 5 canola seeds.  The mature larva chews a small, circular exit hole from which it drops to the soil surface and pupation takes place in the soil within an earthen cell.  Approximately 10 days later, the new adult emerges to feed on maturing canola pods.  Later in the season these new adults migrate to overwintering sites beyond the field.

Please find additional detailed information for CSPW in fact sheets posted by Alberta Agriculture and Forestry, Saskatchewan Agriculture, or the Prairie Pest Monitoring Network.

Also watch provincial reports for updates on surveying underway now.  Alberta Agriculture & Forestry has posted a live CSPW map and online reporting tool for growers.  A screenshot (retrieved 22Jun2017) is included below.