AMES, Iowa – Thanks to a cost-share program sponsored by Practical Farmers of Iowa and the Xerces Society for Invertebrate Conservation, urban farmers can now get cost-share and technical support to help control pests, which helps reduce farm chemical use and improve soil health, according to officials.

“Urban specialty crop farmers face unique challenges, particularly when it comes to adding conservation practices,” said Grace Yi, the Ames-based Practical Farmers of Iowa’s habitat viability manager. “This program supports urban farmers by helping them create habitats for beneficial insects, which can increase natural predation and pollination on their farms.”

Based in Washington, D.C., the Xerces Society for Invertebrate Conservation is an international nonprofit organization that “protects the natural world through the conservation of invertebrates and their habitats.”

Through this program, Practical Farmers of Iowa funds native plants and the associated costs of establishing native insectary strips or beetle banks, while Xerces Society provides technical support and helps develop a habitat plan.

Officials said beneficial insects, such as ground beetles, lacewings (net-winged insects), parasitoid (parasitic) wasps and more, are essential for maintaining healthy ecosystems on farms, which in turn helps farmers provide valuable produce and products to their communities.

Tricia Englebrecht, a flower farmer near Waverly, Iowa, is one of the farmers benefiting from this program.

When asked how she got the idea to incorporate beneficial insects into her operation, she told Farm World, “I watch a lot of YouTube (videos) about flower farming, and general farming and IPM (integrated pest management) practices come up. I am not an expert, but I figured it was something I needed to incorporate in my farm.

“I started using beneficial insect two years ago, so this would be my third growing season using them,” she said. “Practical Farmers of Iowa offers a cost-share program to urban farmers to help pay for pollinator strips. This will help create more habitat for the beneficial insects, along with increased biodiversity.”

She said, “I get my beneficial insects from Arbico Organics (in Tucson, Ariz). They are great to work with and so helpful. I didn’t know where to start and they asked the right questions to help me select what I needed. I don’t necessarily need to manage the insects, but you have to keep (this) in mind when you release them.

“If you release them too early and there is no food source, they will leave to find it or die,” she added. “If you release them when you have a large population of pests, they may not be able to knock that population down.”

She said, “I should also say I only use the beneficial insects in my high tunnel (greenhouse) and not in my outside garden. They are still able to get out of the high tunnel, but it helps that it’s not completely open. The pollinator strips will help create that habitat around my outside garden to hopefully attract more beneficial insects out there.

“As for pros and cons, the pros of using beneficial insects is knocking down pests,” she added. “For example, I use beneficial nematodes to control thrips (slender insects with fringed wings) and green lacewing to control aphids. The cons would be it’s not an immediate solution. It does take time for them to get to work, whether that’s waiting for them to get to the right stage or hatching.”

She said another con is there are always predators to the beneficial insects.

“Last year, I set out the assassin bug eggs, which come in a piece of cardboard, and something came and ate all the eggs off before they could hatch,” she said. Assassin bug eggs are typically laid in clusters, resembling small, brown, bottle-shaped structures, often found on leaves, bark or in soil.

Virgil Schmitt, Iowa State University extension field agronomist in southeast Iowa, told Farm World, “Different predators have different food preferences, so just as in chemical selection, you need to select the predator that has efficacy (the ability to produce a desired or intended result) on your insect of concern.

“Ground beetles target caterpillars, grubs and adults of other beetles, fly maggots and pupae (a stage of an insect – as a bee, moth or beetle – having complete metamorphosis that occurs between the larva and the adult, usually enclosed in a cocoon or case), earthworms, and other small soil dwellers,” he said.

“Ground beetles are not normally applied to the soil,” he added. “The best way to attract them is to provide habitat such as mulch, rocks, or logs where they can hide during the day. This severely limits the ability to attract ground beetle to field crops and retain them in the field.”

He said, “Lacewings target aphids, spider mites (especially red mites), thrips, whiteflies, eggs of leafhoppers, moths, and leafminers, small caterpillars, and beetle larvae, They are often used by organic farmers to manage these insects in hay and soybeans. They are applied as eggs or larvae.

“Parasitic wasps target aphids, caterpillars, sawflies, beetles, leafhoppers, true bugs, thrips, psyllids and flies,” he added. “They sting their target, leaving eggs behind. When the eggs hatch, the larvae consume the target.”

Matt O’Neal, Iowa State professor of entomology, told Farm World, “For systems which need pest management but cannot use insecticides for a variety of reasons, these types of (beneficial) insects have been demonstrated to provide protection. This is especially true for greenhouse systems that grow fresh fruit and vegetables.

“Greenhouses lack the naturally occurring populations of predatory insects and parasitoids, so these purchases can add them quickly,” he said. “Conservation practices (like those being explored by Englebrecht) can improve their impact. The impact of these beneficial insects in outdoor growing systems can be challenging, as they may leave the farm. Also, farms may not have sufficient resources to keep them alive.”

As for their use with crop farmers, he said, “We don’t know enough about the ecology of these insects to manage them consistently for protecting corn and soybeans. They can supplement pest management in combination with resistant crops and insecticides.”

Schmitt said, “My take is that they can be useful for farmers who have the time, energy, and expertise for the more intensive management required and have an effective Plan B at their fingertips if the predators are not effective in a given situation.

“Some people’s Golden Rule is, ‘Whoever has the gold makes the rules.’ Will the farmer be rewarded for the time, energy, and expertise for the more intensive management required?”