Cabbage seedpod weevil

Jennifer Otani
Categories
Week 10

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 ForestrySaskatchewan 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 06Jul2017) is included below.

Provincial Insect Pest Reports

John Gavloski, Scott Meers, Scott Hartley and prairiepest_admin
Categories
Week 10

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


● Manitoba’s Insect and Disease Update for 2017 is prepared by John Gavloski and Pratisara Bajracharya and read Issue #7 (posted July 5, 2017) noting the presence of thistle caterpillar (Vanessa cardui) and larval populations of diamondback moth reaching economically significant levels in the southwest of that province. Cumulative counts of bertha armyworm generated from weekly counts in Manitoba can be accessed here.

● Saskatchewan’s Crop Production News – 2017 – Issue #3 includes the insect update prepared by Scott Hartley and Danielle Stephens. That report includes an update on the red bugs in canola (also described in Week 8) and how to submit samples to that provincial lab, very low numbers of diamondback moth in pheromone traps across that province, initial low numbers of bertha armyworm in pheromone traps, and cabbage seedpod weevil.


● Watch for Alberta Agriculture and Forestry’s Call of the Land and access the most recent Insect Update (July 5, 2017) provided by Scott Meers. That report notes migration of painted lady butterflies which feed on thistles but also soybeans, sunflowers, and dry beans. Soybean and sunflower producers will need to carefully follow the development of a second generation of V. cardui as it could affect those crops by mid-July. Additionally, d
iamondback moth are more numerous than in previous seasons so careful scouting will be required during early pod stages in canola as that stage is the most susceptible to yield losses.

Insect of the Week – Aphidius parasitoid wasp

Jennifer Otani
Categories
Week 10

This week’s Insect of the Week is the Aphidius parasitoid wasp. Their hosts include over 40 species of aphids. Egg to adult development occurs inside the host. New adults chew a hole in the mummified aphid to exit and immediately search for new aphid hosts.

For more information on the Aphidius parasitoid wasp, see our Insect of the Week page.

Parasitized English grain aphid (Tyler Wist, AAFC)
Aphidiidae – adult (Aphidius avenaphis) (Tyler Wist, AAFC)

Follow @FieldHeroes to learn more about the natural enemies that are working for you for FREE to protect your crops!

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

Weekly Update – Greetings!

Jennifer Otani, David Giffen, Erl Svendsen and Owen Olfert
Categories
Week 10

Greetings!

Please access the Weekly Update for July 6, 2017 (Week 10), as either a series of Posts for Week 10 (Jul 06, 2017) or a downloadable PDF.   


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 – Weather Synopsis

Ross Weiss, David Giffen, Owen Olfert and prairiepest_admin
Categories
Week 10

Weather synopsis – This past week, average temperatures were slightly below long-term normals for mid-June.  Average temperatures for June indicate that Alberta temperatures were average, to above average, while Saskatchewan was slightly below than average temperatures. 







Total 30 day rainfall accumulations indicate that conditions are dryer than normal for most of Saskatchewan, the southern Peace River region and large areas of Manitoba.  Central and southern Alberta has had normal rainfall for June.



The lowest temperatures across the prairies over the past seven days (June 29-July 5, 2017) are mapped below.  


In contrast, the highest temperatures recorded over the past seven days (June 29-July 5, 2017) are presented below.  

The updated growing degree day map (GDD) (Base 5ºC, March 1 – July 3, 2017) is below:



While the growing degree day map (GDD) (Base 10ºC, March 1 – July 3, 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 – Predicted Bertha Armyworm Development

David Giffen and prairiepest_admin
Categories
Week 10

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 ManitobaSaskatchewanAlberta 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 – Wheat midge

Ross Weiss, Owen Olfert and prairiepest_admin
Categories
Week 10

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.  P
redicted adult emergence for Saskatoon and Melfort is very similar to last week.  Elliott et al. (2009) reported that adult emergence was affected by inadequate rainfall amounts (May and June). The model was parameterized to take rainfall into account.  Output indicates that emergence at Saskatoon has been limited by inadequate rainfall during June. Rainfall for Saskatoon in June was 37 mm compared to long-term average of 61 mm.  Emergence at Melfort is predicted to be more advanced. June rainfall was 61 mm. 





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 – Predicted Grasshopper Development

Ross Weiss, Owen Olfert and prairiepest_admin
Categories
Week 10

Grasshopper Simulation Model Output – Based on model output, grasshopper development is very similar to long-term averages.  Across the prairies, grasshoppers should be predominantly in the second and third instar stages with more rapid development across southern Alberta. The greatest development was predicted to be across all of the southern regions.

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 grasshoppers:

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 DevelopmentSaskatchewan AgricultureAlberta 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 – Alfalfa weevil

Ross Weiss, David Giffen, Owen Olfert and prairiepest_admin
Categories
Week 10

Alfalfa Weevil (Hypera postica) – Across the prairies, the model indicates that 80% of the population should be in the pupal stage. Adults should be appearing near Saskatoon this week.





In terms of degree-day heat units, the map below reflects the predicted development of alfalfa weevil across the Canadian prairies.



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 – Monarch migration

Jennifer Otani
Categories
Week 10

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 06Jul2017) but follow the hyperlink to check the interactive map! 

Weekly Update – Previous Posts

Jennifer Otani
Categories
Week 10

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

Bertha armyworm (Week 9)

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



Painted lady butterflies (Week 9)
Pea leaf weevil
PMRA Pesticide Label Mobile App
Provincial Insect Pest Reports (Week 8)

Nysius niger (Week 8)

Ticks and Lyme disease


Weather radar


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