Taking Out The Top Five Pests

What do mites, aphids, thrips, whiteflies and leafminers have in common? Aside from being a royal pain in the neck, they’re a motley crew that’s undoubtedly called one of your plants home at one time or another.

On a recent visit to the offices of Greenhouse Grower, Bert Wagemans, the ornamental business lead for the lawn and garden team at Syngenta Professional Products, mentioned these infamous five are the top five ornamental pests globally.

“Any pest insect or mite that appears on a top five or 10 listing did not get there by accident,” says Richard Lindquist, senior technical manager for OHP. According to Lindquist, a broad range of host plants can actually have a negative effect on the active ingredients in chemical pesticides that growers use, but a positive one on the pest.

This wide range can give pests exposure to a number of pesticides, giving them an opportunity to develop some toughness, he adds.

The Short Of It

“Early detection is key,” Lindquist says. “This is simple mathematics. I cannot think of any insect or mite control product that will eliminate 100 percent of an insect or mite infestation.” The most effective products will kill most of the problem, but not all of it, so when it comes to starting treatment, the fewer pests the better.

Many growers bypass preventative applications, so scouting and monitoring for pests are of utmost importance.

Along with early detection, Lindquist says many growers need to keep in mind pesticide resistance. “Somewhere in the world there probably is an insect or mite population that is resistant to each of the current active ingredients,” he says. Fortunately, there doesn’t appear to be a pest population resistant to all active ingredients. With that being said, the goal of any control program should be to rotate or alternate products in several mode of action groups.


When it comes to treating a mite infestation, being under the assumption that the plant canopy is getting thorough coverage is a common mistake for some growers.

“Growers need to utilize more water-sensitive paper or fluorescent dye to check their spray coverage,” says Nancy Rechcigl, Syngenta’s field technical manager who specializes in ornamentals. “It will allow them to see where they are getting the sprays and where they’re not. It will also let them look at the disposition of the spray particles.”

Sampling is another important step in eradicating this pest. Be sure to take leaves from the lower part of the canopy and look at those with a hand lens, says Rechcigl. Because that’s where the mites will typically start out, in the lower canopy first and then they tend to move up. “So when a grower sees them higher up on the plant, it means they already have a pretty good infestation.”

The many life stages of mites are also important to take into account says Keith Santner, technical services manager for Scotts. It’s important to make reapplications for the various stages. Also make the effort to identify the mites properly, because a miticide that works well on two-spotted mites might not have the same desired effect on eriophyid or broad mites, Santner adds.

Lastly, enforce strict sanitation to minimize weeds, which tend to become a preferred safe harbor for mites.


Rechcigl says aphids are usually a fairly easy pest to control. Be sure to monitor your crops with yellow cards, she adds.
Marla Faver, field development scientist at BioWorks, Inc., says some growers may not understand that aphids do not have to mate to reproduce and produce live young. Different aphid species feed on different plant parts and may be missed until the population has exploded.

Santner from Scotts adds many insecticides labeled for aphid control work quite well. “If the crop cycle is over eight weeks, then a good choice is to apply one of the systemic neonicotinoids followed by supplemental applications (on an as-needed basis) of a product that contains the active ingredient acephate and/or a synthetic pyrethroid such as bifenthrin.”


Santner says first and foremost, growers rely too heavily on one active ingredient to kill thrips (like Spinosad). “In greenhouses, growers could be using insect screen to exclude thrips from entering through ventilation equipment. These screens are not necessarily a cheap investment, but it is one that will exclude virtually all other insect pests and weed seed from entering your greenhouses.

Rechcigl agrees a thrip screen is an investment, but growers can recoup their costs over time by having fewer problems and making fewer applications. Consider a quarantine phase, too, for all incoming plants to help fish out any bad apples.

“It’s important to change your application approach and differentiate between flowering and non-flowering crops,” she says. “Flowering crops require a slightly closer spray in order to get good penetration into the flowers. Total annihilation of this pest can take three to six weeks.


For whiteflies, the common mistakes growers make are not starting pest control practices early enough in the production cycle and not continuing them throughout the cycle, Faver says. The correct control is often not timed for the stage in the whitefly lifecycle that the control is effective on.”

Whitefly can sneak up on you Rechcigl says. The adult lays quite a few eggs. If you’re not monitoring with sticky cards, the immature stage can build up quickly. It’s important not to rely on nicotinyl compounds as the only management tool. It should be saved, using it as an application at the proper time, after the crop is fully rooted in, she says.


As mentioned with whiteflies, growers are not starting with preventative measures early enough when it comes to leafminers, Rechcigl says. It’s important to do your homework and understand what crops are susceptible to leafminers.

In regard to leafminer treatment, a common mistake some growers may make is not using block treatments of a product, she says. For leafminers, it’s best to make applications for one generation of leafminer before rotating to another product.

Wetting Your Plant

Kathy Conard, marketing manager of Aquatrols, wants growers to get the most out of their pesticides, and wetting agents are a great place to start.

But before you place that order, read the labels on your pesticides to find out if a wetting agent will work in harmony with your pesticide, advises Rechcigl. “Avoid using adjuvants that are labeled as a ‘spreader-sticker,’ particularly for products that have translaminar activity. It prevents the translaminar activity from working properly.”

Conard says wetting agents (media surfactants) can actually help you stretch your applications of soil-directed pesticide drenches. Pesticides are a costly necessity. Research has shown that wetting agents improve the efficacy of soil-drenches by guaranteeing precise placement throughout the soil profile, which means more pesticide solution is distributed uniformly into and throughout the rootzone profile and not running out the bottom of the pot. 

“When complete, uniform leaf coverage is important for foliar pesticide performance, it is recommended that you add a foliar surfactant (spray adjuvant). Foliar surfactants, when added to the spray solution, significantly improve spreading, coverage and penetration of foliar pesticides, even on hard-to-wet leaf surfaces,” Conard adds. “Complete coverage increases performance and reduces the need for follow-up sprays.”

Leave a Reply

More From Insect Control...
Aquaponics At Brogue Hydroponics

March 30, 2015

10 Things You Need To Know About Aquaponics

Are you curious about expanding into aquaponics? From pest control to equipment, Bob and Jesse Kilgore of Brogue Hydroponics offer 10 factors you need to consider.

Read More
Aquaponics At Brogue Hydroponics

March 30, 2015

Aquaponics Is Making A Splash At Brogue Hydroponics

The owners of Brogue Hydroponics explain why they expanded into aquaponics, and how the shift has helped them uncover a new market opportunity.

Read More

March 26, 2015

10 Greenhouse Products For First-Rate Growing Environments

From coverings to fork-lifts, greenhouse suppliers offer a variety of products to make growing easier. Check out the slideshow to learn more about these, plus several other products that can offer you value, versatility and durability.

Read More
Latest Stories

February 17, 2015

A New Look At Biological Control: Can Plants Affect The…

The success of a biological control program depends on a number of factors including quality of natural enemies, timing of release, release rates and environmental conditions. However, what is typically not taken into consideration is how plants can affect the performance of natural enemies, including attack rate and searching ability. Biological control agents work hard to protect plants, but plants have ways to help themselves, too.

Read More

February 1, 2015

New Pest Control Products For Your Toolbox

Add one of these new insecticides to your IPM program for successful pest control.

Read More

January 29, 2015

IR-4: A Pest Management Resource For Growers

Almost 40 years ago, IR-4 (Interregional Research Project Number 4) began serving the ornamental horticulture industry, helping to facilitate the registration of pest management tools. IR-4 does this primarily by surveying growers about their pest management issues and then hosting workshops to review survey results and set priorities for the coming years. Most recently, IR-4 coordinated a meeting of researchers and industry members on pollinator health and neonicotinoid chemistries to start a discussion on the needed research. The next step will be to get the outcomes from that workshop out to the public.

Read More

January 28, 2015

Biocontrols 2015 Conference & Tradeshow: Peace Tree…

Lloyd Traven, a speaker at the upcoming Biocontrols 2015 Conference & Tradeshow, was one of the industry’s early adopters of biocontrols in the greenhouse. Traven, owner of Peace Tree Farm, is evangelical about the technology as an effective tool for resistance management, as well as improved plant quality that contributes to a grower’s bottom line.

Read More

January 22, 2015

Quality Control With Biocontrols

Make sure the shipment of beneficials that just arrived is viable and ready to go to work in your greenhouse, nursery, or field. Here are five steps you can take to ensure success with your biocontrols.

Read More
As directed by EPA, the bee hazard icon appears in the Directions For Use for each application site for specific use restrictions and instructions to protect bee and other pollinators.

December 9, 2014

Fact Sheet: The Value Of Neonicotinoids To Turf And Orn…

An extensive study of the diverse turf and ornamental industry (“The Green Industry”) reveals that neonicotinoids are the top-rated products used by professionals to control their most important pests in greenhouses, landscapes, lawns, nurseries and trees.

Read More
As directed by EPA, the bee hazard icon appears in the Directions For Use for each application site for specific use restrictions and instructions to protect bee and other pollinators.

December 9, 2014

New Study Finds Neonicotinoids Are Top-Rated Products F…

According to results of a survey by AgInfomatics, professionals in the turf and ornamental industries fear the loss of neonicotinoid products would reduce the quality of their plants and services, increase costs and negatively impact their ability to manage pest resistance.

Read More

November 21, 2014

Ramped-Up Predatory Mite Production To Benefit Growers

Biological pest control company Beneficial Insectary is now producing both Amblyseius (=Neoseiulus) cucumeris and Stratiolaelaps scimitus (formerly Hypoaspis miles) at its facility in California. Domestic production in the U.S. is now benefiting growers in North America by reducing the transit time of perishable predatory mites between producer and grower.

Read More

November 14, 2014

Skagit Gardens To Eliminate Use Of Neonicotinoid Pestic…

Skagit Gardens, a wholesale grower located outside Mount Vernon, Wash., will eliminate all use of neonicotinoid pesticides beginning in January 2015.

Read More

November 11, 2014

Clarification: White House Recommends Sourcing Insectic…

UPDATE: The Obama Administration's addendum to the Sustainable Practices for Designed Landscapes applies only to federal agencies “implementing landscaping practices on agency-owned or leased land or space.”

Read More

October 27, 2014

New Insecticides Offer Alternatives For Growers

Chemistry advances in insecticides broaden growers’ pest management options, without compromising control.

Read More

October 14, 2014

Pollinator Legislation Could Help Solve One Piece Of Th…

AmericanHort encourages industry members to contact their members of Congress to support legislation that would require federal agencies to take greater action to deal with parasite and disease factors impacting the health of managed bees, specifically focusing on Varroa mites.

Read More

October 7, 2014

New Jersey Green Industry Council Will Host Pollinator …

The New Jersey Green Industry Council's 2014 Pollinator Summit is an event and issue briefing for everyone who works in the green industry, agriculture, or related industries. The event will take place Nov. 11 at the National Conference Center, East Windsor, N.J.

Read More

September 22, 2014

Seattle City Council To Vote On Citywide Ban Of Neonico…

On September 17, a committee of the Seattle City Council endorsed a ban on the purchase and use of neonicotinoid products on city property. The measure includes supportive language for sales and use bans for all use patterns, including plants, seeds or products containing neonicotinoids in the city, and support for a national moratorium on products.

Read More
Gary Mangum

August 12, 2014

What Bell Nursery Learned From Growing Without Neonicot…

Determined to find out firsthand what a ban on neonicotinoid pesticides would mean for growers, Bell Nursery CEO Gary Mangum challenged his team to grow without them. Read to find out about the lessons he learned.

Read More
As directed by EPA, the bee hazard icon appears in the Directions For Use for each application site for specific use restrictions and instructions to protect bee and other pollinators.

August 5, 2014

Do You Use Neonicotinoids And Systemic Insecticides? [S…

Take this quick industry survey to help gauge the economic impact of these tools, and inform regulators about their value.

Read More

July 21, 2014

Spider Mites: The Summer Scourge

Spider mite resistance is becoming an increasing problem in greenhouse production. Scouting, biocontrols and miticides can help you take back control of spider mites this summer.

Read More
Joe Bischoff

July 12, 2014

Watch Neonicotinoids: Cutting Through the Clutter Live …

Date: Saturday, July 12 10:45 am – 11:30 am Location: Ballroom 2 Speakers: Joseph Bischoff, PhD, Lin Schmale http://bit.ly/1nhJdQQ Description: Much has been written and is being circulated about the impact that neonicotinoid insecticide use could be having on pollinator populations. Because not all the questions yet have sound scientific answers, too much of what is being written is based on hearsay, innuendo, and fear. Now, some local and a few state bodies are weighing restricting neonicotinoid insecticide use. Joe and Lin will present the facts as research has demonstrated them and how to use the neonics effectively and responsibly with minimal non-target effects. This session is open to all attendees. This session may be eligible for pesticide recertification credit. Tracks: Greenhouse, Hot Topics, Landscape, Nursery Speakers: Joseph Bischoff, PhD, Regulatory & Legislative Affairs Director AmericanHort  

Read More