Monday, 12 September 2016

Natural enemy of Cabbage Root Maggots - Aleochora bilineata (Coleoptera: Staphylinidae)

Beneficial arthropods are present in all field crops.  On the Canadian prairies, several insect pests cause economic levels of damage but natural enemies play an important role in the regulation of all species.  Diseases, parasites, parasitoids, and predators are all examples of natural enemies that will attack and regulate insect pest pests.  Read on to learn more about these organisms and the importance of preserving them in field crop situations!

CANOLA
Cabbage root maggots are a multivoltine complex of up to three species including Delia planipalpis, D. radicum, D. floralis (Diptera: Anthomyiidae).  The cabbage root maggot overwinters within a puparium and emerges in the spring.  Data has shown that continuous cropping of canola on canola contributes to high populations of root maggot so crop rotation is the greatest tool to manage this insect pest whose larval stage feeds upon the canola root.  The beneficial organism that attacks both the egg and pupal stages of the cabbage root maggot is Aleochora bilineata, a small staphylinid beetle which is both predator and parasitoid!  Aleochora bilineata adults hunt and eat Delia spp. eggs but this beneficial organism also parasitizes Delia puparia so, instead of the fly emerging from the root maggot puparium, a beetle emerges - check it out below!



More information is available below from the new Insect Guide:




Also look up this scientific publication to learn more about Aleochora bilineata in canola production systems in Canada: Broatch J.S., Dosdall L.M., Yang R.C., Harker K.N., Clayton G.W.  2008. Emergence and seasonal activity of the entomophagous rove beetle Aleochara bilineata (Coleoptera: Staphylinidae) in canola in Western Canada. Environ Entomol. 37(6):1451-60.

Wednesday, 31 August 2016

This Week at the Farm - Good luck to all our IPM Students! (August 31, 2016)

This week the IPM Program bid farewell to all our summer students.  Wheat and canola still ripens in the field but our students are heading back to complete their degrees!  

We wish our students good luck with their Fall studies and thank them again for their many contributions!

2016 IPM Program's Staff included (L to R) Amanda, Shelby, Jadin, Kaitlin, Celine, Emily, Hannah and Laura.

Friday, 12 August 2016

This Week At the Farm - Red Clover Casebearer Monitoring

RCCB Post
By Laura
The red clover casebearer (Fig. 1) is a small, metallic green moth belonging to the Family Coleophoridae.  The larval stage of the red clover casebearer (Coleophora deauratella) feeds on the contents of clover florettes and eventually the developing seed.  Three species of Coleophora have established in Canada; C. deauratella utilizes red and alsike clover, C. mayrella utilizes red and alsike clover, and C. trifolii utilizes sweet clover. All three species create cases from the floral or seed pod structures of the host plant they utilize.  The larval stage constructs the “case” from its host plant which is worn and carried much like a snail in its shell, hence the common name of “casebearer”.  In the fall, the red clover casebearer moves from floral structures it feeds upon to the ground, carrying its case.  When conditions prompt overwintering, the red clover casebearer retreats within its case and seals the opening with silk.  In the spring, the red clover casebearer can emerge and move in order to find suitable spring conditions.  The larva then pupates within its case and is observed to begin to fly by mid-June in the Peace River region, typically flying over a 6-8 week period.  The metallic, green micro-leps seek their host plant, feeding upon nectar and they lay their eggs on the host plant.  
Figure 1. Red clover casebearer (Coleophora deauratella) larva and adult. The larva creates a case which it wears until it becomes an adult. Image sources: http://www.ukmoths.org.uk/species/coleophora-deauratella/


The IPM lab monitors red clover casebearers throughout the Peace Region. Pheromone traps and sweep-net collections help us monitor the moth flight period, the presence of mature larvae and densities in commercial fields of clovers.  The pheromone traps consist of a commercially available green unitrap, a pheromone lure (Otani, Mori, Evenden) as bait for the males and enclose a Vapona strip to kill and retain the specimens for later identification and counting (Fig. 2).  


http://www.semiochemical.com/unitrap.jpg
Figure 2. Green unitraps mounted singly on posts at the edge of a field are used for pheromone trap monitoring of male clover casebearer moths.
In the span of one week some traps can catch over 1000 casebearers! The casebearers are retrieved then later counted by summer students (Fig. 3) who wear gloves and dust masks to protect against the insecticidal vapona strip and inhalation of the tiny scales of the moths which coat the inside of the traps like dust.
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Figure 3. Summer students count and record the number of casebearers collected from each pheromone trap. This trap had 1793 casebearer moths.

For more information on red clover casebearers in the Peace River region, visit http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/prm4587

Tuesday, 9 August 2016

This Week in the Lab - Prairie Pest Monitoring

Throughout this summer, the IPM lab at the Beaverlodge Research Farm performs weekly monitoring to support the Prairie Pest Monitoring Network (PPMN).  On a weekly basis, Staff perform outings to collect and deploy insect traps at canola fields in the area to help obtain data to represent the region. Target insects include flea beetles, diamondback moths, swede midge, red clover casebearers, bertha armyworm, wheat midge, grasshoppers, and lygus bugs (protocols and descriptions for each insect pest can be accessed at http://insectpestmanagement.blogspot.ca/p/blog-page.html).


These insects, by way of their feeding on leaves, buds, flowers, stems, and seeds cause economic levels of damage either by reducing quality or yield when outbreak populations are not detected or managed at the proper time. Thus, the weekly PPMN outings were necessary to monitor and assess arthropod species and densities throughout the growing season at various fields in the Peace River region. Monitoring species diversity and densities helps us understand the biology of these organisms and provides insight into interactions between the host plants they affect and even some of the natural enemies that help regulate their densities in field crop situations.  


In canola, sticky card and pheromone traps were deployed mid-May at commercial fields of canola just after they were seeded.  Monitoring continued weekly until traps were retrieved early in August as the seeds within canola pods were beginning to change colour.  On August 2nd, all of the traps at the two sites situated in the BC-side of the Peace River region were taken down.  On August 9th, all the traps at the seven sites in the Alberta-side of the Peace River region were taken down. The last picture shown below is from Wilson’s canola field (site id: 2016-005) on August 9th, 2016, when the mean canola growth rating stage was a 5.2 (Harper and Berkenkamp 1975).


Figure 1. Development of the canola at Site ID#2016-005 from May to August of 2016 (Upper L to Lower R) from seeding, cotyledon, rosette, flowering, and pod stages. Photo credits: Celine, Jadin, Emily and Kaitlin.


The past three months in the IPM lab have represented a roller coaster of experiences.  As the final weeks zoom by, I’d like to thank everyone at BRF for being so amazing, helpful, and for being a part of this journey. Here’s to mosquito bites and canola - Cheers everyone and wishing you all the best! :)

- Celine

Sunday, 7 August 2016

2016 Peace Canola Survey - Summary is available now!

The 2016 Annual Peace Canola Survey was completed by Agriculture & Agri-Food Canada staff based at Beaverlodge and Saskatoon.

Since 2003, the annual survey has been performed with the main objectives of (i) collecting insect pest data throughout the region and (ii) to detect the introduction of the cabbage seedpod weevil into the Peace River region.  In 2016, a total of 156 commercial fields of Brassica napus (e.g., each field ≥80 acres in size) were surveyed and no B. rapa was encountered.

Fields were surveyed by sweep-net using 50 - 180° sweeps on the following dates in these areas:
• July 5 near Whitelaw, Berwyn, Grimshaw, Dixonville, Manning, Hotchkiss, Hawk Hills, Notikewin, Blue Hills, Buffalo Head, La Crete.
• July 6 near Fort Vermilion, Blumenort, Valhalla, La Glace, Westmark, Woking, Spirit River, Blueberry Mountain, Silver Valley, Bonanza, Bay Tree, Beaverlodge, Halcourt, Wembley, Grande Prairie, Clairmont, Sexsmith, Teepee Creek, Bezanson, Dimsdale, Huallen, Fairview, Vanrena, Hines, Creek, Worsley, Eureka River,
• July 7 near Rycroft, Webster, Hythe, Wanham, Girouxville, Watino, Eaglesham, Belloy, Dawson Creek, Rolla, Dow River, Clayhurst, Cecil Lake, Fort St. John, Farmington, Valleyview, Guy, Falher, Reno, Nampa, Peace River, Marie-Reine, McLennan, Whitemud Creek.

Sweep-net samples were frozen then processed to generate data for a total of 21,278 arthropods which were identified and categorized into 38 taxa. The 2016 summary includes 15 economically important pests of canola reported from 156 surveyed canola fields plus data related to rotational practises in the Peace River region.

The 2016 summary is available as a downloadable PDF file.

THANK YOU to the following hard working AAFC staff who surveyed†, processed‡, and mapped∞ this data: Jadin Chahade1†‡, Kaitlin Freeman1†‡, Holly Spence1†‡, Hannah Avenant1†‡, Laura Stewart1†‡, Celine Coschizza1†‡, Emily Lemke1†‡, Owen Olfert2†∞, Taylor Kaye2†∞, Shelby Dufton1‡, and Amanda Jorgensen1‡.


Finally, and MOST IMPORTANTLY, Thank you to our canola producers for allowing us to sample in their fields!

Friday, 22 July 2016

So far in our monitoring.....

What we're seeing so far in our field monitoring.....


We finished our Annual Canola Survey of the Peace on July 8th but we are processing the samples from the 156 sites.  Please watch our IPM Lab Blog though – I will post our survey results there first.

Earlier this spring, there were cutworms and fields in the Peace were sprayed to try and manage that – I have no idea the number of acres though.  To date, our monitoring has shown low DBM and BAW pheromone count interceptions.  Wheat midge was forecasted to be lower populations through most of the entire Peace this season, however, midge flight synchronized fairly well with wheat anthesis in the south Peace.  We have seen some higher lygus bug numbers in some of our canola survey samples but the persistent rain throughout June-present has been a major factor in all our field crops.  More specifically, we aren’t seeing the typical nymph densities that we’d expect in the canola so far (because we know many have died owing to rain falling every 4-6 days from bolting through to early flowering) – stay tuned for the survey results though.  Grasshoppers are present but the situation is nowhere near the high risk originally forecasted back in January for the Peace. 

Almost all the fields we’ve seen around the south and north Peace have received some fungicide whether it’s been wheat, peas, or canola.  As Jim notes, producers are sometimes keen to tank-mix insecticide with the fungicide application and only the agricultural industry people will know those statistics on what product has been sold so far this season. 

From what I’ve seen so far, I would have expected a bit of grasshopper spraying by now and the next 10 days of heat and sun may bring about some spraying for Lygus but most canola will be at the pod stage by then and surely with the heat.  Overall, there are some very nice crops are out there despite some water damage.  Apart from cutworms, it hasn’t been a big insect pest outbreak year so far in the Peace.

Monday, 18 July 2016

Rearing parasitoids that attack Lygus

As mid-June approaches, Lygus in the Peace Region will be starting to lay their eggs into the stems and leaves of canola, alfalfa, and other plants. Later in the summer, when then the canola and other crops are more developed, adults and nymphs (Fig. 1) can damage crop yields when they feed on the juicy plant material of these crops. They pierce through the plant tissues with their sucking mouthparts- which often leave visible lesions on stems, buds, flowers and pod surfaces. Buds and flowers drop as a result and the seed pods often turn brown and shriveled from being fed on. The economic damage on canola in the Peace region is all caused by Lygus species native to North America.
Figure 1. Lygus nymph on the left and adult Lygus on the right (image retrieved from http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex741).

Lygus can be pale green to reddish-brown to black and have a distinct V-shape centered on their dorsal side (Fig. 1). Lygus overwinter as adults.  Theyemerge early in spring.  Canola is most susceptible to damage from Lygus at late flowering through the early pod stages.
The phenology of Lygus varies by region with 2-3 generations per year in the south of the Canadian prairies to only one generation per year in the Peace River region.  Lygus feeding damage will depend upon growing conditions. Abundant rainfall helps canola compensate, whereas hot, dry growing conditions favour Lygus development and often result in high populations capable of causing damage and yield losses.  If canola fields are adjacent to hay fields, early season monitoring of Lygus densities within the alfalfa can often help growers anticipate Lygus in bolting and early flowering canola.
The economic threshold for Lygus in canola varies by canola crop stage and is applied at late flower or early pod (Table).  It depends on sweep-net monitoring at multiple sites within a field and counting both adults and nymphs (3rd-5th instar stages). When densities exceed the economic threshold is exceeded registered foliar-applied insecticides are used to reduce feeding damage and protect the developing pods and seeds which then results in quality and yield being maintained.  There are a number of natural enemies that help reduce and regulate Lygus populations; notable wasp parasitoids include species from the Family Mymaridae and Braconidae.  In North America, the braconid, Peristenus pallipes has been reared from Lygus lineolaris and L. keltonii as well as L. shulli. A potential biological control agent also worth mentioning is Peristenus digoneutis which is a parasitic wasp or European origin that can attacks nymphal stages of Lygus rugulipennis  Poppius but has shown a degree of host preference for North American species of Lygus and has been released to in eastern Canada in strawberry production systems.   Historically, Peristenus digoneutis was released on the Canadian Prairies in the 1970’s but failed to establish in detectable numbers.  Efforts still continue to investigate P. digoneutis as a biocontrol agent for Lygus found in canola grown in Canada.

Figure 2.  Peristenus digoneutis here is shown laying an egg in a lygus nymph (image retrieved from: http://www.biocontrol.entomology.cornell.edu/parasitoids/peristenus.php ).
In our lab, we have prepared Peristenus rearing cages and mass collections were performed during the last week of June.  Mass collection involves sweeping the canopy then retrieving live specimens back for processing.  The density of Lygus is recorded and nymphs are isolated for rearing.

Peristenus wasps attack and lay an egg within 1st-2nd instar stages of Lygus nymphs (Fig. 2).  Once the egg hatches, the Peristenus larva develops within the body of a Lygus nymph so we rear the nymphs until they either mature to adults or a Peristenus larva emerges from the host to then drop down to the soil and spin its cocoon (Fig. 3).  We monitor the number of Peristenus cocoons that arise from the Lygus nymphs then the cocoons will be transferred to collaborators at AAFC-Lethbridge who will continue to rear and obtain the live wasps the following spring.

Figure 3.  Peristenus rearing cages at Beaverlodge Research Farm.

Sources:
Haye, T., et al. "Controlling Lygus Plant Bugs (Heteroptera: Miridae) with European Peristenus relictus (Hymenoptera: Braconidae) in Canada – Risky Or Not?" Bulletin of Entomological Research 96.2 (2006): 187-96.