In Case You Missed It: Two-Spot Cotton Leafhopper – a New Pest of Hibiscus.

*Fig. 1.* *Two-spot cotton leafhopper. Photo by A. Revynthi, University of Florida.*

Just when we think we have Thrips parvispinus under control, a new pest is threatening tropical ornamentals. The two-spot cotton leafhopper (Amrasca biguttula) is mainly a pest of – you guessed it, COTTON – but also attacks hibiscus. Growers in Ontario should be aware of this pest if importing hibiscus cuttings from the Southern U.S., where this pest has currently invaded.

There’s been lots of good information shared on this pest recently. Read on for a summary relevant to ornamental growers, including what to look for, effective pesticides and what actions you should take NOW.

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Lewis Mites 2025 – a Poinsettia Problem that’s Here to Stay?

*Lewis mite damage on poinsettia. Photo by OMAFA.*

Let’s face it: although Lewis mites (Eotetranychus lewisi) used to be more of a cyclical pest, this mite has been consistently bad in poinsettia the last few years. As regular Lewis mite infestations now seem to be the new normal in poinsettia, this week is the time to to start thinking about your pest control plan for Lewis mite.

Whether you choose the preventive route or the wait-and-see approach, knowing which strategies and chemicals are working is critical. Read on for tips on dipping to prevent mites along and what we learned from last year‘s chemical approaches.

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Pesticide Rotation Guide for Thrips parvispinus in Canadian Greenhouses

By Sarah Jandricic (OMAFA) and Judy Colley (Plant Products)

*A female (left) and male (right) Thrips parvispinus on a mandevilla flower.*

With the arrival of mandevilla, dipladenia and hibiscus cuttings, now is the time to start planning your management program for Thrips parvispinus. Unfortunately, it looks like this pest is here to stay in North America, and in the tropical plant industry at large.

In this post, we’ll focus on pesticide rotations to manage pesticide resistance, as well as a few tips and tricks to make sure your pesticides stay working.

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Potted Chrysanthemums 2024: Dips, Thrips and Threats

Every year at this time, growers start to think about strategies to minimizing western flower thrips on their chrysanthemum crops. This year, Thrips parvispinus is causing extra concern, given that chrysanthemum is one of its reported hosts.

Although there have been no reports yet of Parvispinus damaging chrysanthemums in North America, it’s still good to exercise a bit of caution. However, jumping the gun and spraying chemicals will likely just disrupt your biocontrol program for western flower thrips, leaving you with a bigger mess on your hands.

This post contains information on things you can do to put your mind at ease about all sorts of thrips this chrysanthemum season.

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Garden Mums 2024 – Tips, Tricks, and Production Bits

This post was contributed to by Abigail Wiesner, Drs. Sarah Jandricic, and Chevonne Dayboll.

As we feel temperatures rising, summer is on its way – and so are garden mums! This post has updated information to help you optimize your irrigation, fertilizer, pest management programs and more in garden mum production.

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Poinsettia Pest Management Pointers 2023: Receipt Through Potting Up.

Poinsettias are here! In the next few posts we’ll be breaking down production into into 4 key growing periods: Receipt/Propagation, Early Production, Late Production, and Finishing.

This post on propagation will cover things you can do now to treat pests and diseases in your cuttings to prevent BIG problems later. And make sure to check out Dr. Chevonne Dayboll’s previous post on ensuring cutting quality.

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Thrips parvispinus (“Pepper Thrips”): The Importance of Inspecting Plants and Dipping Cuttings from Florida

I’ve written about the tropical pest Thrips parvispinus, now being called “pepper thrips”, infesting certain tropical ornamentals in Canada before. But it appears this pest has become widespread in Florida.

As Ontario sources much of its plant material from Florida, it’s a good idea to exercise caution, even on non-tropical plants. The known host range of this pest is evolving, and thrips have the potential to hitch-hike on less-preferred plant hosts and spread to more preferred hosts in your greenhouse.

Read on for information on the situation in Florida and what you can do to help protect your greenhouse from this pest.

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Looking Ahead to 2023: Preparing for Spring Crops

This post was jointly written by Dr. Chevonne Dayboll and Dr. Sarah Jandricic

It’s hard to believe, but as the first snow hits the ground here in Niagara, that means its time to think about spring crops again!

This post gathers some of the most important things to plan and prep for in the greenhouse, including ordering inputs, preventative maintenance, and your pest management and PGR plans!

Think of this post as your “to-do” check list for the month of December, as the time to plan all this is NOW, before your spring production begins.

We’ve also linked to some helpful videos we’ve recorded from our GrowON webinar series that are relevant to spring crops. They’re worth a re-watch – or a first watch – if you haven’t seen them before!

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Tropical Thrips Species Intercepted on Plant Material in Ontario: Be Aware – But Don’t Panic.

This post was co-written by A. Summerfield (Vineland Research and Innovation Centre) and S. Jandricic.

*Figure 1. Thrips parvispinus is generally dark coloured (though the head and thorax can be lighter than the abdomen), has bright red ocelli and clear patches at the top of its wings.*

Increases in global trade, along with decreased use of harsher broad-spectrum pesticides makes it easier for insect species to move around the world. Because of this, it is becoming more common to find unusual pests coming in on plant material. It’s important that we are prepared and know what to do when something like a new thrips species makes an appearance.

The tropical thrips species Thrips parvispinus has been popping up in various parts of the globe in recent years and was intercepted on plant material in two Ontario greenhouses in 2021/2022. Read on to learn what we know about this species and what you should do if you suspect you have them.

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Poinsettia Pest Management Pointers: Receipt Through Potting Up.

Poinsettias are almost here! Instead of covering the whole crop cycle, this year we’re breaking posts down into 4 key growing periods: Receipt/Propagation, Early Production, Late Production, and Finishing.

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