Managing Thrips: How to ID thrip species

Part 1: Understand the enemy 

The first step in managing thrips is knowing what species you are dealing with. This will help to understand where the various life stages of thrips reside, the extent of feeding damage that they can cause, the probability that they are disease vectors, and the best mode of action to take to manage them.  

There are over 6000 species of thrips has been identified so far, some feed on fungus, others on plants, and some are even beneficial. The species we will discuss today are plant feeders.  

Take the following steps to narrow down the species? 

Step 1. Research what type of thrips are the most common in your region first.  

Step 2. Ask yourself what crop you are growing and look up which species are known to prefer this plant. 

Step 3. Narrow down the feeding behavior (feeds on flowers, vegetative growth, or both). These steps should help roughly narrow down the type of species you are dealing with.  Onion thrips mostly feed on vegetation while western flower thrips prefer feeding on flowers. 

Step 4. You can take it even a step further by grabbing a microscope and counting hairs on its pronotum and observing ocelli color. Thrip species have unique physical characteristics that can be identified once you know what you are looking for. All you need is a good microscope with 200x magnification. Below we have narrowed the three most common thrips found in Greenhouse crops in North America. Once we know the species we are dealing with, we can narrow down the most effective way to control them. 

In our next post we’ll be talking about preventative actions you can take to reduce thrip outbreaks.