Greenhouse Management: What are some basic facts growers should know about aphids?

Mark Brotherton: Many different species of aphids attack ornamentals and they have a very short life cycle. Some species can be more crop specific, but other common species like the green peach aphid or melon aphid are broad feeders. They are relatively easy to manage if dealt with early on, but a population can explode quickly if not addressed. And while they are easy to control, aphids can damage plants quickly. Aphids can also be seen by the naked eye and, when found, they are often in colonies or large masses. And when they feed, they leave behind honeydew that can turn into sooty mold, causing the to be aesthetically unappealing.

“Scouting should also be done once a week, at minimum. This should not just be done for aphids, but other insects and diseases as well. It’s especially important for aphids because they can colonize and reproduce rapidly.” — Mark Brotherton

GM: What are some strategies for dealing with aphids?

MB: There’s basic IPM, sanitation, proper plant spacing. Aphids do prefer lush, healthy plants, so do not over fertilize your crops, that can be attractive to aphids. And be sure to scout regularly. You can minimize the damage and minimize an infestation of aphids if you detect them early and treat immediately. And then you have options of biological control agents. There are several pesticides that can control aphids and some of them are more specific and are compatible with beneficials for a conjunctive program. In our portfolio, Rycar and Hachi-Hachi SC both work very good to control all aphid species. Rycar, specifically, is softer on beneficials, and Hachi-Hachi SC gives you a one-two punch with your piercing, sucking insects as well as thrips.

GM: Should growers be more preventative or reactive when combatting aphids?

MB: Growers are going to have their own strategies and do what fits their business. At the end of day, in my opinion, preventative approaches are always better. Nine times out of 10, you’re going to spend less money and time combatting aphids (and other pests) and get a better plant in the end. You won’t have to worry about walking into the greenhouse one morning and find that your entire greenhouse is covered in aphids or another pest. Scouting should also be done once a week, at minimum. This should not just be done for aphids, but other insects and diseases as well. It’s especially important for aphids because they can colonize and reproduce rapidly. If conditions are conducive to aphid activity, you would ideally scout the facility twice per week to minimize the severity of an outbreak should you get one.