In Case you Missed it: UofF Webinar on Latest Thrips parvispinus Research

On March 12th, 2025, Dr. Alexandra Revynthi’s lab (University of Florida) gave an amazing update on what they’ve been working on with regards to Thrips parvispinus. A lot of this was important basic knowledge about their biology, such as development time and survival at high temperatures. There were also quite a few lab and small greenhouse trials looking at potential biocontrol agents.

Some of this will be information we build on to create effective IPM programs for Parvi in the future. But some of these findings, you could put into use right now.

You can go watch the full webinar using the link in the full blog post, or read my summary notes and see what I thought were the important take-aways.

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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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In Case you Missed it: “A Pain in the Parvi” GrowON Webinar Recording (Plus, Another Thrips parvipsinus Webinar with GrowPro!)

In case you missed the GrowON webinar by myself and Judy Colley from Plant Products on Jan 29th, we’ve now uploaded to Youtube!

You can find it the ONFloriculture Youtube page, along with lots of other useful videos and webinars.

Are recorded webinars not your thing? Well, then you have two additional options!

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Pesticides for Parvispinus: Results of an On-Farm Trial

*Female T. parvispinus (left) on a mandevilla flower; a smaller male (yellow, right) can also be seen.*

Although the invasive pest Thrips parvispinus continues to threaten tropical ornamental crops, the good news is that the sky isn’t falling. Producing crops like mandevilla, schefflera and hoya is still possible, at least in a closed greenhouse setting.

Although developing a reliable biological control program for this pest is probably a few years off, a suite of pesticides is available in the U.S. and Canada to successfully manage T. parvispinus.

This post covers these pesticides, their relative efficacy and demonstrates outcomes when used in an 8 month on-farm trial in mandevilla.

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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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