Poinsettia Thrips Beware! There’s a New Predator in the Greenhouse
There are thousands of thrips species that feed on plants. A new study conducted by University of Florida researchers investigated ways to manage Echinothrips americanus, also known as poinsettia thrips, a globally important pest of many crops grown in greenhouses.
“Thrips are a particularly big problem for greenhouses, and poinsettia thrips are a pretty large thrips species,” says Erich Schoeller, UF/IFAS postdoctoral researcher. “We were looking for a really large predator for a really large pest.”
The research team studied Franklinothrips vespiformis Crawford, which is a generalist predator with a large appetite.
“I was surprised by how effective this predator was in just a short time,” Schoeller says. “We went from high densities of the pests to almost nothing in just two weeks of having released the predatory thrips.”
These results were seen in many crops including kava, poinsettia, and industrial hemp.
Franklinothrips vespiformis Crawford, a beneficial thrips, goes on the hunt for other thrips to eat.
Photo courtesy of UF/IFAS
The predator’s intense appetite is great for controlling pests, but once they have eaten all available prey within the greenhouse, they often die of starvation. Researchers wanted to know if they could feed the insect a supplemental diet of brine shrimp eggs, or cysts, to sustain their populations during times of low prey populations.
Many studies over the years have tested this method by feeding the predators pollen, other insect eggs and artificial diets, but many of the diets tested are too expensive for large-scale operations to implement.
Brine shrimp eggs are commercially available and often used as fish food. They have been tested globally as a supplemental food for biological control agents with some consistent positive results in the past five years. However, scientists had not tested the suitability of a brine shrimp egg diet on this species of predator.
Turns out, thrips do like the eggs. But not just any brine shrimp eggs will work. The cysts used are specially processed and sold by a commercial insectary in Israel. Once the pest populations had been consumed by the predatory thrips, researchers saw them complete additional generations only when the supplemental food source was provided.
“The exciting thing is that we proved that we could keep these predators in the greenhouse longer by feeding them,” Schoeller adds.
For more, continue reading at blogs.ifas.ufl.edu.
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