Yale’s Marsh Botanical Garden sits on a plot of eight acres, including six greenhouses. The space supports research and activities of the university with Yale faculty members cultivating plants year-round. Chris Bolick, Plant Resource Facilities Manager, has invested in Integrated Pest Management to make this research more sustainable.
Integrated Pest Management (IPM) aims for a four-step approach to control unwanted insects (pests) in a way that is least detrimental to the surrounding environment (including people). First, pests are monitored and identified. Second, prevention is the preferred method of management; sunlight, plant placement, soil composition, and irrigation are all factors that are considered. Third, an action threshold is set to determine at what point the pest population exceeds reasonable limits and control measures are taken; this often means that natural predators are released to limit the population of the unwanted pests. And fourth, the result is a harmoniously balanced ecosystem.
Bolick follows this step-wise approach at Marsh. Over time, he has determined which insects are most problematic at Marsh (like broad mites and mealybugs) and which insects are their most effective predators. Most of the predator species are mites which are so small that they are barely visible to the naked eye. Bolick uses Neoseilus cucumeris to control broad mites, and the Cryptolamus for mealybugs.
Every two weeks, Marsh receives a delivery of these natural predators. They are placed in dishes next to the plants and they crawl out towards the plant and attack their natural prey without harming the plant in the process.
In addition to the mites, Bolick and his crew use a few other organisms to help with pest control. Nematodes, a type of round worm, can be sprayed onto the leaves and stalks of a plant, where they will prey on unwanted fungus gnats, shore flies, and thrips.
Wasps and rove beetles are also used as natural predators. One species of wasp arrives in larvae form, stuck to tiny cardboard tags. Bolick and the other gardeners place the tags throughout the greenhouse and as the larvae hatch the wasps are released into the greenhouses to target their natural prey.
The use of organic biopesticides, which are made from naturally-occurring compounds, complements these strategies.
“There’s plenty of innovation in the industry that we try to stay on top of and profit from, says Bolick. “At the moment I’m excited by a new class of organic biopesticides that we’ll be trialing this fall to complement and expand upon the ones we currently use.”
In the twelve years since Bolick began working at Marsh Botanical Gardens, he has seen a transformation in pest management for the better. Marsh has reduced its use of conventional pesticides by approximately 90%. Bolick emphasizes that Marsh is always refining its IPM program to maximize sustainability, efficacy, and cost.
Yale is committed to building a more sustainable world. By doing what we do best—integrating science, the humanities, and our community—Yale creates, tests, and adopts innovative solutions to the environmental and social challenges we all face.