Archive for the 'Spotlight' Category

Ant Control Weather

When the temperature starts dropping it’s time to go on the offensive against ants. Ants are one of the biggest overlooked factors that lead to biological control failures. Many common species “farm” honeydew producing pests, including aphids and mealybugs. They eat and fight off predators, transport pests to new areas, and will even shelter aphids and mealybugs inside their ant mound. Cooler temperatures slow ants down, making them more vulnerable to attack by the vigilant farmer.

Formica ants on AntPro

Formica ants visiting AntPro bait station

One of the most effective control measures is baiting ants with low toxicity ant baits. We recommend using bait dispensers filled with liquid boric acid baits for sugar feeding ants. Dry granular borate ant baits can also be used. Boric acid won’t kill the foraging ants immediately, letting them bring the poison back to the mound where it can kill the queen. Don’t be alarmed if you don’t see results right away. Because of boric acid’s low toxicity, the same reason it is effective at killing whole mounds, it may take up to a month to see a reduction in ant numbers. Boric acid bait stations can also be used to prevent ant infestations. There are various strategies for bait station placement depending on the kind of ants and the amount and type of area needing protection. If the ants don’t accept the bait, try diluting it or adding more flavor. For example, ants in strawberry crops are more attracted to bait when strawberry juice is mixed in.

Physical disruption of ant nests provides more immediate results. Using a shovel or piece of rebar to break up the ground around the entrance to the colony forces ants that would be foraging to rebuild. If food supplies are low, the ants inside may eat their young. This allows beneficial insects to get to work without interference. Unfortunately, this is only a temporary solution and mounds will need to be repeatedly disturbed to distract the ants from tending to their honeydew source.

Other control measures you can use are nematodes, orange oil drenches, and sticky barriers. Read our Ant Bulletin and our founder Everett J. Dietrick’s paper Argentine Ants Must Be Suppressed for more information on ant control. This fall we’re also offering discounts on ant control supplies.

On an ant control side note, in a field study where they used only sticky barriers for ant control in an organic citrus grove, researchers found more aphids in the trees without ants! Their conclusion was that, as a side effect of excluding ants, they were also protecting the aphids from earwigs. After analyzing the populations of other aphid predators in their grove, they determined that earwigs are one of the main natural controls of aphids in the springtime. Populations of some of the other predators grew in response to growing aphid populations, but not fast enough to control them without the help from the earwigs.

Discussing the study at Rincon-Vitova, we thought of other predators we see a lot in orchards and gardens that would be blocked by sticky barriers – wolf spiders and ground beetles. Releasing aphid predators to back up the naturally occurring ones might have helped the aphid problem in the study grove. Or maybe another method of reducing ant interference without stopping crawling predators from finding the aphids, such as baiting, would have worked better in their case. Aphids can also be blasted off plants with a strong jet of water, which might be a good strategy if you are using sticky barriers. This study is a reminder of how complex these ecological systems are, and that we have to be alert to the unexpected effects our pest control efforts.

(The study mentioned, “Effects of the concurrent exclusion of ants and earwigs on aphid abundance in an organic citrus grove,” was written by Josep Piñol, Xavier Espadaler, Núria Cañellas and Nicolás Pérez and published in the August 2009 issue of BioControl (vol. 54, no. 4, pp. 515-527).)

-Alia Tsang, Bug Farm intern


Talking IPM with Andy Force at the Foellinger-Freimann Botanical Conservatory

 View of the Botanical Gardens from W Jefferson Blvd, Ft. Wayne, IN
While I was at home in Fort Wayne, Indiana, visiting my family for the holidays, I visited with Andy Force, the Supervisor of Horticulture for the Foellinger-Freimann Botanical Conservatory. The conservatory consists of three indoor gardens and showcases over 500 species of plants and 72 types of cacti. A Jaboticaba tree, native to South Brazil, is one of the oldest plants in the conservatory, and has been growing since the gardens opened in 1983.
Andy has been working with the conservatory since 1989, when this Staghorn fern was roughly the size of a basketball.



Staghorn Fern

Staghorn Fern

 Back in those days, the pest control was accomplished with chemicals, and once a week they would bring in the machines and spray everything. Andy noticed that spraying did help to reduce the pest populations, but only temporarily. In 1991 he started using beneficial insects, and has been fine-tuning his program ever since. “One of the great things about the beneficial insects, that I keep telling people, is that the beneficial insects usually find the problems that we have before we know we have them. We’ve come out here and seen there are mealybugs here and we looked at it and found Cryptolaemus already on the plant working on it. So a lot of the time we don’t need to do anything except watch.”

Andy notices that the south side of the rooms in the conservatory get the most pest problems, and it is there that he does the most releases of beneficial insects. “The bananas, normally mealybugs like, but they tend to leave them alone. I bet if they were on that [the south] side of the house, they would get more mealybugs.” Since Andy has been working with an IPM program since 1991, he has an excellent handle on what pest problems his plants get, as well as when to expect them. The Ficus tree gets a lot of thrips, for which he periodically releases Atheta coriaria, Amblyseius cucumeris, and Orius insidiosus. Also, Andy has seen that the thrips are attracted to the light coming in through the exit door so he’ll open the door and shoo the thrips outside, as another control strategy. The Butterfly Palm frequently gets a scale infestation, and receives many of the Lindorus lopanthae beetles sent to the conservatory. Andy uses the Encarsia formosa cards on the Hibiscus to help combat the whitefly problems, and in the spring, the cacti bloom and typically get spider mites, which he controls with releases of the predatory mite, Phytoseiulus persimilis.

This Jaboticaba tree has been growing in the conservatory since 1983. As the tree matures, the bark peels and takes on a look similar to camouflage.

This Jaboticaba tree has been growing in the conservatory since 1983. As the tree matures, the bark peels and takes on a look similar to camouflage.


In my opinion, Andy exemplifies how one should approach biological control. He is very familiar with the plants in the collection and the typical challenges that are associated with each. Not only is he observant of the pests and natural enemies that help control them, but he is also patient with the level of control that is achieved naturally. Andy understands that biological control is not total eradication of a pest problem, but rather, suppression of a pest to a level such that the pest is in balance with the natural enemies present, and that the damage is not devastating to the plant. Further, Andy embraces the idea that for biological control to be effective releases need to be proactive, not reactive. Every year before spring, Andy sets up advance orders to ship monthly for the duration of the year. Andy knows when to expect certain pests, and releases the beneficials in anticipation of these outbreaks, which allows the beneficial insects to establish themselves in the conservatory and seek out the pest problems, often even before they are apparent. 



Stay tuned to learn about the Foellinger-Freimann Botanical Conservatory’s involvement with CITES and the exciting story that Andy Force shared with me about illegally smuggled orchids.

Spotlight: Hurricane Ike Visits Shangri La

Recently Kyra was catching up with Jennifer Buckner, Epiphyte Specialist at Shangri La Botanical Gardens and Nature Center on the Texas Gulf Coast (in Orange), after September’s Hurricane Ike. Jennifer explained that preparing for evacuation is very different depending on if a storm is going to bring more wind or more water. The high winds of Hurricane Rita three years ago ripped the roofs off the greenhouses and exposed precious orchids to damaging exposure to the sun. Some have still not recovered. So it was decided to put the plants under the benches to be out of the sun until the staff could get back in.

Holly Hanson, Volunteer Coordinator (and plant caregiver) explains how gut-wrenching it was to drive away. “You don’t know if what’s been done was the best way to protect the plants.” Unfortunately Ike brought water rather than wind, so many precious plants got soaked under the benches and most of the greenhouses are still full of water. She said the staff has been kind of depressed, but sees some benefits from the rebuilding and is celebrating with a Greenhouse Open House on the Saturday before Thanksgiving.

The educational non-profit is faced with massive rebuilding. Not just a leader in ecological pest management, Shangri La was the first project in Texas to achieve LEED Platinum certification! Gary Outenreath, Director of Horticulture, has long been a leader in promoting safe and sustainable pest control, making sure visitors know that no toxic chemicals are used at the facility.


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