Talking about wheat midge, its parasitoids, and the value of wheat stubble

Wheat stubble, particularly if it’s beneath 2021’s canola crop, has hidden value in the form of beneficial Macroglenes penetrans wasps that begin to emerge as the canola reaches early to mid-flowering stages. 

In 2014, we were excited to observe high numbers of these mighty parasitoid wasps in our canola sweeps at several locations throughout the Peace River region and we were able to track the highest numbers back to canola standing above wheat stubble! Since then, we’ve tracked M. penetrans to even more sites throughout the region so we urge growers to consider that 2020’s wheat stubble contains a powerful ally – but only if they manage it well in 2021!

AAFC photo of wheat midge (Sitodiplosis mosellana).
Photo: AAFC-Beaverlodge, A. Jorgensen and S. Dufton”

AAFC photo of Macroglenes penetrans.
Photo: AAFC-Beaverlodge, S. Dufton”

Graphic summary of the lifecycle of the wheat midge: Review Figure 6 (Image credit: Extension Entomology, NDSU) shared within the "Integrated pest management of the wheat midge" (Knodel 2016). https://www.ag.ndsu.edu/publications/crops/integrated-pest-management-of-the-wheat-midge-in-north-dakota

Access more information related to this topic:

• Jorgensen, A., Otani, J, Evenden, M.  2020.  Assessment of available tools for monitoring wheat midge, Sitodiplosis mosellana (Diptera: Cecidomyiidae). Environmental Entomology. 49(3): 627-637.  https://doi.org/10.1093/ee/nvaa017

• Jorgensen, A., Evenden, M.L., Olfert, O., Otani, J. 2020. Seasonal emergence patterns of Sitodiplosis mosellana (Diptera: Cecidomyiidae) in the Peace River region, Alberta, Canada. The Canadian Entomologist.  153: 222–236. (Published Online 2020Jan15). https://doi.org/10.4039/tce.2020.76 

• Dufton, S.V., Laird, R.A., Floate, K.D., Otani, J.K. 2020.  Diversity, rate, and distribution of wheat midge parasitism in the Peace River region of Alberta, Canada. The Canadian Entomologist. (Accepted 2020Dec22; Published Online 2021Apr14). https://www.doi.org/10.4039/tce.2021.7 

• Predators & Parasitoids Series 2 podcast entitled, “Secret Agents in the Stubble” where Jennifer Otani describes the relationship between wheat stubble and M. penetrans.

• A Growing Point article entitled, “Wheat midge parasitism in the Peace River region” which provides an overview about parasitism levels in wheat midge and its and dominant parasitid, M. penetrans.

• Learn more about midge tolerant wheat

• A fun infographic describing why and how wheat midge pheromone traps are used to assess risk (Jorgensen 2016).

• A visual guide used to train student assistants to identify wheat midge adults (Jorgensen 2016).

• Field Heroes “Scouting for beneficials in cereals”

• Field Heroes new Field Guide (free PDF copy)

Finally, every year growers across the Canadian prairies have four valuable sources of information supporting their management of wheat midge:

1. Refer to annual forecast map to assess if fields in your region are anticipated to carry a higher risk of potential high densities of viable wheat midge in 2021 - Maps are normally available by mid-January and onwards for Saskatchewan and Alberta while the PPMN’s prairie-wide map is normally available in March. Before seed is purchased, growers can access these forecast maps to assess potential risk for wheat midge. Growers in high areas of risk should consider midge-tolerant cultivars.  In June, review these maps to help gauge regional risk levels for wheat midge.

2. From June to July, access the Prairie Pest Monitoring Network’s “Weekly Updates” – Predictive model outputs are updated weekly through the growing season. These estimates use current weather data observed across the Canadian prairies along with biologically known parameters necessary for wheat midge to develop. More specifically, the outputs estimate dates when 50, 80, or 90% of regional wheat midge populations have begun to emerge from cocoons. Ideally, growers begin in-field scouting from 90% onwards in order to most accurately assess their actual in-field populations and apply economic thresholds (if they’re growing wheat cultivars susceptible to wheat midge). 

3. By mid-June, track provincial weekly reporting resources to find updated estimates of regional wheat midge numbers intercepted in pheromone-baited traps (Alberta's Live Map, Saskatchewan’s Crop Production News, or Manitoba’s Crop Pest Updates). Cumulative counts of adults in the traps serve as estimates that again help growers prioritize the need for in-field scouting in their region. Every field can vary so in-field scouting is needed to accurately assess pest densities but also to refrain from spraying insecticide when numbers remain below the thresholds. In the latter situation, opting NOT to CONTROL preserves resident natural enemies like Macroglenes penetrans. 

4. Links detailing how to perform in-field scouting AND the two economic thresholds for wheat midge are available from Alberta Agriculture and Forestry, Saskatchewan Agriculture, and Manitoba Agriculture and Rural Development.

Return of our student team!

 We're really pleased to welcome back our student team for the 2021 field season! These folks are coming soon to a field (and field plots) near you!!  Well, that's true ONLY if you're fortunate to be in the Peace River region!

Learn more about Maiya, Aarika and Donovan.  They join Shelby, Amanda, and me and we're the IPM Team for the summer of 2021!

Coming back to work in the IPM program

Hi, my name is Aarika and I am more than excited to be coming back to work in the IPM program again this summer!

About Me

I am going into my fourth year of Bachelor’s of Science specializing in Psychology at the University of Alberta. I am interested in pursuing medicine, specifically neurology or psychiatry. Although my studies are a bit different from agricultural entomology research, I have become very passionate in this area of agriculture from working at the Beaverlodge Research Farm last year. I was THRILLED when I knew I would be coming back to work here this summer. I grew up on a grain farm near Valhalla Centre and have been eager to become more involved. I have been helping out in the field when I get the chance to and learning to drive more of the equipment.

Last year I learned so much valuable information in the IPM program including starting to monitor insects in fields. I was able to review various pieces of scientific literature and take online courses to expand my knowledge on insect predators, pests, economic thresholds, insecticides, and more. 

Figure 1. Aarika rolling canola in her family’s fields.

What I Look Forward to... This year, I am excited to have the opportunity to do more fieldwork in different areas and on a wider variety of insects. I look forward to continuing learning about insect monitoring, scouting, and gaining more practical experience. This job has given me a greater awareness of what isgoing on in a smaller scale (insect scale) in those large fields! I have scouted some of my family's fields already and have seen insects already working away! I am eager to see how this year is in comparison to previous years as I have seen a lot of fluctuation with the weather.

Anyways, I am very excited to be working with the wonderful team for my second year here in the IPM program! They are truly incredible people to work with and are passionate about what they do.

Back for the 2021 field season!

Hello everyone! My name is Maiya and I am a returning student in the Insect Pest Management (IPM) Program at the Beaverlodge Research Farm. I worked with the IPM team last year, but this is my first year both returning to the program and working in-person. I will be at the Farm for the 2021 summer from May to August. 

I recently completed my third year at the University of Alberta pursuing an undergraduate degree in Science, majoring in Biological Sciences and Psychology. Though I have not focused on insects in my studies, I have taken a few ecology and zoology courses that often use entomological examples. I am looking forward to applying my school-based knowledge to the job and gaining more practical experience in biology this summer. 

Previous work with the IPM program brought me a new appreciation for the wide range of insects with which producers must cope to grow a successful crop. Last summer I was only able to do fieldwork on my family’s farm in the Peace region (Fig. 1) and performed several online tasks and training while working from home. Therefore, I am eager to spend more time outside getting some hands-on experience with pest monitoring and laboratory techniques this summer. 

Figure 1. Maiya holding a sweep-net used for monitoring Lygus bugs and other insects in her family’s canola field.

Back for the 2021 field season!

Hi there! I’m Donovan, a returning student in the Insect Pest Management Program at the Beaverlodge Research Farm. Last summer, I worked remotely with the IPM team, mainly performing online insect-related tasks and research. This year, however, I’m working on-site from May to August, and I can’t wait to get that true pest monitoring experience!

I am a third-year student at Carleton University pursuing a BSc in Ecology while minoring in Statistics. Growing up, animals of all shapes and sizes intrigued me (Fig.1). Whenever I went to zoos, I never wanted to leave until I had the chance to see every animal, much to my parent’s occasional discontent. Later in my educational career, I realized I loved translating my ecological research into numbers (or vice versa), which prompted me to incorporate statistics into my studies.

I have a deep passion for entomology since working for the Canadian National Collection of Insects housed at AAFC-Ottawa. While working there, I marveled over the sheer diversity of insects and all the weird and wacky forms they possess. When I worked remotely for the Beaverlodge Research Farm, I was fascinated by how much of an impact insects have on agriculture, whether beneficial or detrimental, and I’m looking forward to expanding my knowledge on these compelling arthropods with the IPM team this summer!

Figure 1. Donovan celebrating the 12th birthday of his miniature labradoodle, Keegan.