Weekly Update (August 22, 2019; Wk 20) Otani, Weiss, Giffen, Trudel, Svendsen, Iron, Turkington, Olfert, Vankosky

Good luck with harvest!

This is Week 20 and the last of the Weekly Updates for 2019!  Watch for special releases during the fall and winter, as information is updated.  Please subscribe to the Blog or bookmark the Blog to stay informed.  Changes are coming for 2020!

We thank all the many folks who have been monitoring, collecting, compiling and generating data throughout this growing season - your exceptional efforts are appreciated and critical!  We also sincerely thank the many researchers, talented technical support staff, and especially the many students who have been contributing to agricultural field crop protection, insect pest management, and arthropod biodiversity this season!

Please access the complete Weekly Update either as a series of Posts for Week 20 (August 22, 2019) OR a downloadable PDF. Be sure to check out the Insect of the Week - this is our final doppelganger of the 2019 field season!

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

Subscribe to the Blog by following these easy steps!

Weather synopsis (August 22, 2019; Wk 20)

Weather synopsis –  The PPMN's mapping of current data is complete for the 2019 growing season as of Wk 19.  Please refer to the AAFC Drought Watch website, access Environment Canada's Historical Data website, or your provincial weather network.

Across the prairies, average temperatures were slightly cooler than long term climate normals (Fig. 1).

Figure 1. Mean temperature difference (°C) from Normal observed across the Canadian prairies for the past month (July 23- August 19, 2019).  Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (22Aug2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

Significant rainfall amounts were reported across parts of the northern Peace River region, southern AB and SK (Fig. 2). Across the prairies, rainfall amounts for the past 30 days have been lowest across the southern prairies (Fig. 3 and 4). 

Figure 2. Accumulated precipitation (mm) observed across the Canadian prairies for the past seven days (as of August 21, 2019).  Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (22Aug2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

Figure 3. Accumulated precipitation (mm) observed across the Canadian prairies for the past 30 days (as of August 21, 2019).  Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (22Aug2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

Figure 4. Percent of average precipitation (%) for the Canadian prairies for the past 30 days (as of August 21, 2019).  Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (22Aug2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

Growing season rainfall amounts have been below average across much of Manitoba, southern regions of AB and west-central SK, and in the far north of the Peace River region (Fig. 5). 

Figure 5. Percent of average precipitation observed across the Canadian prairies for the growing season (April 1-August 21, 2019).  Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (22Aug2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

The growing degree day map (GDD) (Base 5 ºC, April 1-August 18, 2019) is below (Fig. 6):

The growing degree day map (GDD) (Base 10 ºC, April 1-August 18, 2019) is below (Fig. 7):

The lowest temperatures (°C) observed the past seven days ranged from at least 10 down to below -2 °C in the map below (Fig. 8).

Figure 8. Lowest temperatures (°C) observed across the Canadian prairies the past seven days (to August 21, 2019).

Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (22Aug2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

The highest temperatures (°C) observed the past seven days ranged from at least 17 up to at least 33 °C in the map below (Fig. 9).

Figure 9. Highest temperatures (°C) observed across the Canadian prairies the past seven days (to August 21, 2019).

Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (22Aug2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

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

Wanted - Slugs in field crops (August 22, 2019; Wk 20)

Reminder - This year, wet field conditions contributed to slug issues in cereals and canola.  Researchers based at the University of Alberta are seeking live slug samples from field crops.  Please take note of their collection protocol and help, if possible please!

Watch for feeding channels on the upper surfaces of the flag leaf in wheat and plan to scout in the evening!

Figure 1. Deroceras reticulatum, the "grey field slug", on wheat growing near
Crooked Creek AB (August 2, 2018; det. Lien Luong).

Figure 2.  Flag leaf feeding damage  on wheat caused by the grey field slug (Deroceras reticulatum).
Photo taken near Crooked Creek AB on August 2, 2018, by J. Otani.

Grey garden slugs were observed when field scouting was performed in the evening from 8:30-10:30pm in 2018 (Fig. 1 and 2).  As the temperatures decreased, the slugs moved up the wheat stems, climbing to the topside of the flag leaf and onto the wheat heads although they did not appear to feed at the developing kernels.   Wheat was hand-collected by clipping stems ~20cm above the ground and these samples later revealed a density of 1.04 slugs per stem (n=465 stems) causing the above damage (Fig. 2). 

Specimens were forwarded to L. Luong (U of A) who identified the slugs from the above field as one species, Deroceras reticulatum, the grey field slug.  The majority were juveniles. The grey field slug is the most common to occur in the home garden.

Thanks to Dr. John Gavloski (Manitoba Agriculture) who prepared the following in relation to slugs in field crops: 

• Slugs are a complicated problem because most general insecticides don’t work well on them.  
• Sluggo Professional (PCP#30025) is registered for slugs in field crops. It is a bait, which must be consumed by the slugs to be effective but it could be expensive on a large field.  
• Often insecticides don't work well on slugs and it may be related to the mucous coating slugs exude.  
• Be wary, if an insecticide is applied, the product will likely not affect the slugs but it will kill the ground beetles and other natural enemies that prey upon or parasitize slugs and could exacerbate the slug problem.  
• Growers using no-till or minimum till operations may consider tillage to help reduce future levels of slugs.  

Health Canada has an overview of snails relating to gardening posted here.

West Nile Virus and Culex tarsalis (August 22, 2019; Wk 20)

West Nile Virus Risk –  Health Canada posts information related to West Nile Virus in Canada.  Health Canada also tracks West Nile Virus through human, mosquito, bird and horse surveillance.  Link here to access the most current weekly update (August 10, 2019). The screenshot below was retrieved 22Aug2019 as reference but access that information here.

The following is offered to predict when Culex tarsalis will begin to fly across the Canadian prairies (Fig. 1). Protect yourself by wearing DEET!  This week, regions most advanced in degree-day accumulations for Culex tarsalis, the vector for West Nile Virus, are shown in the map below.  As of August 18, 2019, areas highlighted orange are on the verge of approaching sufficient heat accumulation for mosquitoes to emerge.  Areas highlighted red in the map below should now have C. tarsalis in flight.

Figure 1. Predicted development of Culex tarsalis, across the Canadian prairies (as of August 18, 2019).

Once adults emerge, the following map demonstrates how quickly a Culex tarsalis mosquito carrying WNV can become fully infective (i.e., when it has accumulated 109 base 14.3° degree days) - it's a matter of days, depending on the region (Figure 2).  For example, as of August 18, 2019, areas highlighted orange in the map below had C. tarsalis flying that required 18-20 days to become fully infective.

Harvest Sample Program (Aug 22, 2019; Wk 20)

Remember - The Canadian Grain Commission is ready to grade grain samples harvested in 2019.  Register online to receive a harvest sample kit (by October 15, 2019).  Samples are accepted until the end of November but send as soon a harvest is complete.

This is a FREE opportunity for growers to gain unofficial insight into the quality of their grain and to obtain valuable dockage information and details associated with damage or quality issues.  The data collected also helps Canada market its grain to the world!

More information on the Harvest Sample Program is available at the Canadian Grain Commission’s website.

In exchange for your samples, the CGC assesses and provides the following unofficial results FOR FREE:

     • Unofficial grade*
     • Dockage assessment on canola
     • Protein content on barley, beans, chick peas, lentils, oats, peas and wheat
     • Oil, protein and chlorophyll content for canola
     • Oil and protein content and iodine value for flaxseed
     • Oil and protein for mustard seed and soybeans
     • Falling number for wheat
     • Vomitoxin (deoxynivalenol or DON) levels for wheat and corn

Many producers find having both grade and quality information on their samples before delivering their grain to be helpful.  Sign up for a harvest sample kit before October 15, 2019.

Provincial Insect Pest Reports (August 22, 2019; Wk 20)

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

• Reminder - Manitoba's Crop Pest Updates for 2019 are posted here. Access Issue #13 posted August 13, 2019, noting continued grasshopper concern, the presence of new generation flea beetle adults in canola, and a repeated call for grasshopper surveyors.

• Saskatchewan's Crop Production News has released Issue #7 (featuring information related to aphid thresholds).

•  Alberta Agriculture and Forestry's Agri-News includes an insect-related item in the August 19, 2019 edition with summer field scouting information related to flea beetles and bertha armyworm.

Crop reports (August 22, 2019; Wk 20)

Crop reports are produced by:
• Manitoba Agriculture (August 20, 2019 or access the current online report)
• Saskatchewan Agriculture (August 13-19, 2019) or access the current online report).
• Alberta Agriculture and Forestry Crop Report (August 13, 2019) or access the current online report)

The following crop reports are also available:
• The United States Department of Agriculture (USDA) produces a Crop Progress Report (read the August 20, 2019 edition).

• The USDA's Weekly Weather and Crop Bulletin (read the August 20, 2019 edition). 

Review the 2019 WEEKLY UPDATEs!

Many thanks to all our contributors!  Access the WEEKLY UPDATE as either a series of Posts OR downloadable PDF file for the entire 2019 growing season:

Wk 1 (April 08) - Otani, Vankosky
Wk 2 (April 15) - Otani, Vankosky, Giffen, Weiss, Trudel, Mori, Olfert
Wk 3 (April 26) - Otani, Giffen, Weiss, Trudel, Olfert, Vankosky
Wk 04 (May 02) - Otani, Giffen, Weiss, Trudel, Olfert, Vankosky
Wk 05 (May 9) - Otani, Giffen, Weiss, Trudel, Turkington, Svendsen, Olfert, Vankosky
Wk 06 (May 16) - Otani, Giffen, Weiss, Trudel, Turkington, Svendsen, Barkley, Olfert, Vankosky
Wk 07 (May 23) - Otani, Weiss, Giffen, Trudel, Turkington, Svendsen, Tansey, Olfert, Vankosky
Wk 08 (May 30) - Otani, Weiss, Giffen, Trudel, Turkington, Svendsen, Parent, Mlynarek, Olfert, Vankosky
Wk 09 (June 6-7) - Otani, Weiss, Giffen, Trudel, Turkington, Svendsen, Olfert, Vankosky
Wk 10 (June 13) - Otani, Weiss, Giffen, Trudel, Turkington, Svendsen, Olfert, Vankosky
Wk 11 (June 20) - Otani, Weiss, Giffen, Trudel, Turkington, Svendsen, Jorgensen, Olfert, Vankosky
Wk 12 (June 27) - Otani, Weiss, Giffen, Trudel, Turkington, Svendsen, Olfert, Vankosky
Wk 13 (July 5) - Otani, Weiss, Giffen, Trudel, Svendsen, Olfert, Vankosky
Wk 14 (July 11) - Otani, Weiss, Giffen, Trudel, Svendsen, Olfert, Vankosky
Wk 15 (July 18) - Otani, Weiss, Giffen, Trudel, Svendsen, Olfert, Vankosky
Wk 16 (July 25) - Otani, Weiss, Giffen, Trudel, Svendsen, Olfert, Vankosky
Wk 17 (August 1) - Otani, Weiss, Giffen, Trudel, Younie, Svendsen, Olfert, Vankosky
Wk 18 (August 8) - Otani, Weiss, Giffen, Trudel, Younie, Svendsen, Olfert, Vankosky
Wk 19 (August 15) - Otani, Weiss, Giffen, Trudel, Younie, Svendsen, Olfert, Vankosky
Wk 18 (August 8) - Otani, Weiss, Giffen, Trudel, Younie, Svendsen, Olfert, Vankosky
Wk 19 (August 15) - Otani, Weiss, Giffen, Trudel, Younie, Svendsen, Olfert, Vankosky
Wk 20 (August 22) - Otani, Weiss, Giffen, Trudel, Svendsen, Iron, Olfert, Vankosky

Review the 2019 INSECT OF THE WEEK!

The 2019 Insect of the Week lineup featured species you may encounter while scouting in field crops; the initial four weeks targeted introduced species while the remaining 12 weeks featured insect doppelgangers.  Many thanks to all our contributors!

Need a refresher or simply want to keep our 2019 lineup a click away? Here's the 2019 INSECT OF THE WEEK lineup for the growing season:

WK05 (May 7) - Brown marmorated stink bug
WK06 (May 13) - Lily leaf beetle (Lilioceris lilii) and its natural enemy, Tetrastichus setifer
WK07 (May 21, 2019) - Spotted wing drosophila (Drosophila suzukii Mats.)
WK08 (May 27) - Japanese beetle (Popillia japonica)

WK09 (June 3) - Doppelgangers: Pea leaf weevil and other Sitona species
WK10 (June 10) – Doppelgangers: Bertha armyworm and clover cutworm
WK11 (June 17) - Doppelgangers: Wheat midge vs. Lauxanid
WK12  (June 24) - Doppelgangers: midge vs. parasitoid
WK13 (July 2) – Doppelgangers: Cereal leaf beetle vs. Collops beetles
WK14 (July 9) – Doppelgangers: Grasshoppers
WK15 (July 15): Doppelgangers: Lygus bug vs. Alfalfa plant bug
WK16 (July 22): Doppelgangers: Lygus bugs nymphs vs. aphids
WK17 (Jul 29) - Monarch vs. Painted Lady
WK18 (Aug 6) - Doppelgangers – Good vs. good (ladybeetle larva vs. lacewing larva)
WK19 (Aug 12) - Doppelgangers: Hoverflies vs. bees vs. yellow jacket wasps
WK20 (Aug 19) - Doppelgangers: Giant water bug vs Cockroach

Review the 2019 Cereal Rust Risk Reports - Turkington

The Prairie Crop Disease Monitoring Network (PCDMN) represents the combined effort of our prairie pathologists who work together to support in-field disease management in field crops.  

In 2019, the PCDMN released a series of weekly Cereal Rust Risk Reports throughout May and June.  Information related to trajectory events based on forecast and diagnostic wind fields and cereal rust risk is experimental, and eight reports were OFFERED TO THE PUBLIC FOR INFORMATIONAL PURPOSES ONLY:

Wk 05 (May 9 Report)
Wk 06 (May 16 Report)
Wk 07 (May 23 Report)
Wk 08 (May 30 Report)
Wk 09 (June 3 Report)
Wk 10 (June 10 Report)
Wk 11 (June 17 Report)
Wk 12 (June 24 Report)

Upcoming Meetings and Conferences (August 22, 2019; Wk 20)

Upcoming Meetings and Conferences – The following agricultural insect pest-related meetings and conferences will be held - be sure to re-confirm dates and details as events are finalized:

• October 3-5, 2019:  6th Joint Meeting: Entomological Society of Saskatchewan and Alberta.  Information is posted at: https://entsocalberta.ca/news-and-events/annual-general-meeting/ 

• October 23-25, 2019:  The 2019 Western Forum on Pest Management and associated Western Committee on Crop Pests will meet at Kelowna BC. Information and registration links are available here. 

• TBA:  Information for the upcoming Entomological Society of Manitoba Annual Meeting will be available here.

• November 13-14, 2019:  The 2019 Canola Discovery Forum will be held at Winnipeg MB.  More information is available here.  

• December 11-12, 2019:  Farming Smarter Conference and Trade Show will be held at Lethbridge AB.  More information can be accessed here.  

• January 14-15, 2020:  CropSphere Agricultural Conference will be held at TCU Place in Saskatoon SK during Crop Production Week.  More information can be accessed here.  

• January 21-23, 2020: The Manitoba Ag Days show will be held in Brandon MB. More information will be available here.  

• January 28-30, 2020:  FarmTech 2019 will be held in Edmonton AB and information is available at http://farmtechconference.com/  with registration typically opening early in November.

• October 19--21, 2020:  The Joint Annual Meeting of the Entomological Society of Canada, Entomological Society of Alberta meets at Calgary AB.  Information will be available here. 

Please send other IPM-related conference and meetings to Jennifer Otani to update this information.

Previous Posts (August 22, 2019; Wk 20)

Click to review these earlier 2019 Posts:

2019 Risk and forecast maps - Week 2

Alfalfa weevil - Week 11

Bertha armyworm (predicted development) - Week 12
Bertha armyworm (monitoring) - Week 19

Cabbage seedpod weevil - Week 11
Cereal aphid manager APP - Week 12
Cereal leaf beetle - Week 9
Crop protection guides - Week 6
Cutworms - Week 5

Diamondback moth - Week 15

Field events - Week 10
Field heroes - Week 6
Flea beetles - Week 5

Grasshoppers - Week 19

Insect scouting chart for Canola - Week 5
Insect scouting chart for Flax - Week 5

Lygus in canola - Week 18

Monarch migration - Week 13

Painted lady butterfly - Week 8
Pea leaf weevil - Week 10
Prairie Crop Disease Monitoring Network - Week 5
Preparing grains for market - Week 15

Ticks and Lyme disease - Week 4
Timely IOTW to review - Week 13

Weather Radar - Week 6
Wheat midge - Week 17
Wildfires - Week 8

Wind trajectories - Review Page for list of PDFs for Weeks 1-12

Insect of the Week (Aug 19) - Doppelgangers: Giant water bug vs Cockroach

Years ago, I was walking home from the University of Alberta campus on a September evening, watching the ground, as entomologists are wont to do, when I saw a huge insect on its back on the sidewalk. It was just off of a major crosswalk under a streetlight. Upon a quick glance, I knew it was one of two things: a giant water bug or a cockroach. Either way, I needed it for my collection, so I carefully collected it using the only container I had on hand. I say that I “carefully collected” it, because water bugs are known for their painful bite and I did not want to take any risks. From inside the container, it was clear that I had scooped up a water bug.

Giant water bugs (Lethocerus americanus) are true bugs (Hemiptera) that belong to the family Belostomatidae.  There are over 150 species of water bugs in the Belostomatidae, but most are quite large (> 2 cm). Belostomatids are usually found in ponds, lakes, or slow moving rivers and streams. They spend most of their time in the water, but disperse between bodies of water by flying (except in species that have reduced wings and are flightless), at which time they may be found around streetlights or porchlights. They are predators of other insects, small fish, snails, amphibians, and other animals that they encounter in the water. Giant water bugs use their forelegs to capture prey and then use their long beak-like proboscis to feed on their prey. First, they inject enzymes into their prey that breakdown prey tissues into a liquid. Then they feast on a liquid lunch by sucking their victim dry. Their bite can be very painful. These ‘toe-biters’ are best avoided, but they are important beneficial insects in aquatic ecosystems.

Giant water bugs can be easily mistaken for adult cockroaches (especially the American cockroach, Periplaneta americana, Blattodea: Blattidae). Both water bugs and cockroaches havelarge, oval shaped bodies that are usually brown coloured. A casual glance or quick encounter with either may lead to a case of mistaken identity. But, upon closer examination, some key differences are easy to see:

1. Cockroaches have long, obvious antennae. Water bugs do not appear to have antennae unless closely examined.
2. The head and eyes of water bugs are visible from above. The head and eyes of cockroaches are hidden underneath the pronotum.
3. Cockroaches have spiny legs evolved for running and quick movement. All six of their legs look the same. Water bugs have forelegs adapted to grabbing prey (raptorial legs). Their legs are also adapted for swimming and have no obvious spines.

Cockroaches are usually classified as pests by humans, but some provide important ecosystem services (i.e. they are decomposers) and others are television and movie stars (i.e. Madagascar hissing cockroaches).




Giant water bug
cc-by-nc 4.0 Christian Schwartz

American cockroach
cc-by-nc 2.0 K. Schneider

Contributed by Dr. Meghan Vankosky (@vanbugsky). 

The case of the innocuous versus the evil twin: When making pest management decisions, be sure that the suspect is actually a pest. This can be challenge since insects often mimic each other or look very similar. An insect that looks, moves and acts like a pest may in fact be a look-alike or doppelganger.
Correctly identifying a pest enables selection of the most accurate scouting or monitoring protocol. Identification and monitoring enables the application of economic thresholds. It also enables a producer to select and apply the most effective control option(s) including method and timing of application.  For the rest of the growing season, the Insect of the Week will feature insect crop pests and their doppelgangers.

Doppelgangers may be related (e.g. same genus) or may not be related, as in the case of monarch butterflies (Danaus plexippus) and viceroys (Limenitis achrippus).  Doppelgangers are usually relatively harmless but sometimes the doppelganger is a pest yet their behaviour, lifecycle or hosts may be different.

Review previously featured insects by visiting the Insect of the Week page.

Weekly Update (August 15, 2019; Wk 19) Otani, Weiss, Giffen, Trudel, Younie, Svendsen, Olfert, Vankosky

Greetings!

Week 19 for 2019!  Please access the complete Weekly Update either as a series of Posts for Week 19 (August 15, 2019) OR a downloadable PDF. Be sure to check out the Insect of the Week - this growing season features doppelgangers to aid in-field scouting!

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

Subscribe to the Blog by following these easy steps!