Aphid Awareness in 2026

This week we’re talking about a pest that seems to be on everyone’s radar this spring: Aphids.

PROBLEM: As the weather warms up and we get closer to Mother’s Day, more pest management questions start to hit my desk. The last thing you want to find before your crops go to retail is an infestation that slipped the net and turned into a major infestation. This week has been chock-full of aphid-related inquiries, so be on the alert for these tenacious little critters over the next few weeks.

NICK’S TIP: Aphid populations can explode in a short period of time when temps are warm and plants are growing quickly. Keep the following in mind as you’re scouting crops, and act quickly if you find an aphid hot spot.

Common ID Characteristics

For those of you who may not be as familiar with insect pest identification, aphids:

• Are small and vary in size from about 1.5 to 4 mm long, depending on the species.
• Do not typically have wings, but “flyers” can be present on occasion.
• Come in a variety of colors, including (but not limited to) green, yellow, orange, red/pink, black and pale/whiteish.
• Have little appendages (cornicles) on the rear part of their abdomen that look almost like little exhaust tailpipes. These can generally be seen easily without magnification, which makes these structures a key ID trait for aphids.

Where To Look (Generally …)

While aphids aren’t super picky about what they feed upon, they tend to gravitate to certain crops first. However, you will consistently find them in the same general location on plants when they appear (in most cases).

Calibrachoa × hybrida, peppers (Capsicum annuum), and sweet potato vine (Ipomoea batatas) are often the first crops that I hear reports of aphid pressure on from growers each spring.

Certain cultivars seem to be “tastier” to aphids than others, so it’s not unusual for them to appear in just one or two varieties initially.

While I have never seen a resource that characterizes which cultivars of different crops are preferred by aphids, it’s important to make note of these “magnet varieties” in your operation. Once you identify them, it can be helpful to your scouting efforts to place extra sticky cards near these varieties or near combo planters that have these cultivars in the mix.

Most often, aphids can be found feeding on the youngest developing leaves and shoots on a plant. They can typically be found on the undersides of leaves in the upper part of the canopy during the heat of the day. This reduces their exposure to the elements and helps them to avoid predators. (Note: Root aphids are the only major exception to this rule, as they feed exclusively on below-ground plant parts or at the crown near the soil line.)

Where To Look (Specifically! ...)

Under ideal conditions, a newly birthed aphid (yes, they give live birth…) can become reproductive in as little as around seven days. Each female aphid can produce as many as 60 to 100 nymphs during the approximately 20- to 30-day reproductive period in its life cycle. This is why aphid infestations seem to explode suddenly if they aren’t detected early. The rate at which insects develop is heavily influenced by temperature, so ranges with warmer setpoints or areas in the greenhouse that are simply warmer by virtue of physics are the first places you should scout.

Greenhouses with a temperature setpoint range that doesn’t get much below about 68F (20C) and run warmer during the day should be scouted more frequently and rigorously.

Check hanging basket lines frequently. The higher up your plants are and the closer to the greenhouse glazing material they sit, the warmer and cozier they will be for aphids.

• While most aphids lack wings, they will crawl along basket lines to the next plant when the one they were born on becomes too crowded.
• Place sticky cards more liberally in HBs and physically take baskets off their line to scout when you check them—a quick glance from the ground is not enough!
• Pay close attention to crops near side vents, exhaust fans, exterior doors or near breezeway air inlets.

Aphids in the landscape “wake up” when ambient outdoor temperatures stay consistently warm or when sudden, unseasonal warm spells hit. A nice, warm greenhouse full of a veritable buffet of tender, tasty bedding plants is the first place they will run when there’s slim pickings out in the landscape. This is why pre-season maintenance to replace compromised side and ridge vent screens is important.

(Note: If roll-up sides are your primary means of venting, take special care when scouting and keep a close eye on pots/flats along the outer edge of your production blocks.)

Management

If an aphid outbreak occurs in your greenhouse, implement control measures ASAP. Traditional chemical controls should include insecticides that provide quick knock-down control (at least two in different IRAC groups), and at least one translaminar or systemic insecticide that provides longer-term mop-up control.

For insecticide options, check out the 2026 GrowerTalks Insecticide, Miticide and Fungicide Guide HERE (also in Spanish HERE).

If you primarily use biocontrols in your IPM strategy, be sure you have an “in case of emergency” plan in place to curb a major outbreak. While we are huge fans of biological IPM strategies to keep pest pressure low, they can struggle to take on overwhelming pressure or massive influxes from the field. Proactively talk to your BCA supplier about best options to knock down major outbreaks without causing major harm to your beneficials.