When Thrips parvispinus first came on the scene in Ontario, our one goal was to knock back this pest any way we could. Four years later, we are suffering the effects of an all-chemical program. This includes high costs, along with insecticide resistance developing in two-spotted spider mite, which used to be managed biologically before Parvipsinus came along.
Based on OMAFA’s work with commercial farms, along with input from technical reps from biocontrol companies, we’ve come up with a more refined IPM program for Mandevilla that balances Parvispinus control while taking into consideration other pests, as well as costs.
I’ll be going over this program in detail over a 3 part series, so buckle up!
On Wednesday, December 17th, please join Greg Bryant , Technical Lead at Beneficial Insectary, for an hour-long exploration of what nematodes can do, if you treat them right.
To attend, please continue reading and click on the registration link in the webinar poster or at the end of the post.
As December winds down, thoughts are now turning to spring crops. This can include spring bedding crops or nursery plants coming out of their winter sleep. Both of these can bring onslaughts of pests like thrips, fungus gnats, shore flies and even weevils. Nematodes are an important natural enemy in fighting these pests, and are often the gateway into using more biocontrol. But are you using them to the best of their abilities?
Please join Greg Bryant , Technical Lead at Beneficial Insectary, for an hour-long exploration of what nematodes can do, if you treat them right.
To attend, please continue reading and click on the registration link in the webinar poster orat the end of the post.
Fungus gnats and shoreflies will always be a nuisance in greenhouse crops and, at high levels, potentially damage roots and transmit certain plant pathogens. Recently, key pesticides for these pest have been lost, either through de-registration or via production decisions from manufacturers. Read on to see options for controlling fungus gnats in greenhouse crops.
MSU Extension has updated a 16 page guide to biocontrol agents that are commercially available to control greenhouse pests.
Developed in collaboration with Kansas State University and the Ontario Ministry of Agriculture, Food and Rural Affairs, this fantastic resource includes pictures of each organism, their active temperature ranges, and key facts that will help growers find success using biological control. Read on to download your copy now!
As much as we all hate thrips, there are, frankly, worse problems to have. And it’s name is Leafminer. These flies cause just about the ugliest damage we see in floriculture (Fig. 1), and they have incredible pesticide-resistance capabilities. Outbreaks seem to go in cycles, and I’ve had quite a few gerbera and mum crops come across my desk with leafminer this past 2 weeks.
This post covers chemical options (BawHawHawHa!!! Oh… Sorry… I’ll get myself under control now) and non-chemical options for leafminer, as well as how their control fits into the big picturein greenhouse IPM programs.
Western flower thrips adult on an open Mandevilla flower. Photo credit: Caitlin MacDonald, USEL student.
Now that the warm weather is finally upon us, it’s time to start worrying about thrips control.
What we’ve learned over the years is that pesticides just don’t cut it – the only reliable chemical for western flower thrips in Ontario is DDVP, which requires constant application. This means biological control is your best bet. Here’s a summary of the most effective tools, tricks, and timing, to ensure your biocontrol dollars are well spent.
Entomopathogenic nematodes – used to control fungus gnats, shoreflies and thrips – are often a “gateway bio” into biocontrol use in greenhouses. This is because not only are they effective and easy to use, but they’re generally compatible with insecticide use. Readily applied with regular spray equipment or through drip lines, nematodes can even be tanked mixed with pesticides to save on labour costs.
In this post, I’ll share some of my research at NC State, looking at which commonly used pesticides in Canadian and U.S. greenhouses are safe to use with nematodes.
Spraying nematodes in your greenhouse for fungus gnats, shoreflies, or thrips? Then check out this article published in the January 2015 issue of Hort Matters (OMAFRA’s Horticultural newsletter):
Researchers realized that nematodes can “stick” to the inside of spray tanks, reducing the number of nematodes coming out of the nozzle as you spray. This is unlikely to be a problem using backpack sprayers (since the volume is so small), but could be an issue if you use a towed sprayer on wheels.
What’s the solution? Agitation, agitation, agitation.
To keep your nematode numbers consistent throughout the application, do your best to keep nematodes in suspension. And, if you have any concerns about your application technique, it’s easy enough to assess if you have a microscope (or have a friendly neighbourhood OMAFRA agent with one).
Nematodes (S. feltiae) preparing to enter an adult western flower thrips. Photo by R. Buitenhuis (Vineland).
Nematodes are around 0.5 mm long, and can be easily seen using the low magnification setting on a scope. A black background makes them easier to see. Live nematodes are usually serpentine or “J” shaped, and often wiggle slightly. Dead nematodes are stick straight.
By counting the number of live nematodes in a small volume of your original spray solution (1 mL should do it), you can compare this to the number of nematodes in the same volume (1mL) from the nozzle dribble at the end of your application. Seeing a huge reduction here? Then you may have a problem.
To ensure nematode health, also follow these other tips:
Air temperature should be less than 30 C at application time
Apply during low light levels since nematodes are UV sensitive
Nematodes can be stored in a refrigerator (4C) but should be used within 4 weeks of receipt
Do not apply nematodes though sprayers that exceed 300 psi
