I have just returned from the The Sixth International IPM Symposium in Portland, OR. It was more focused on agriculture than I would have liked, thought there would be some ornamental stuff but it was educational. I was most-impressed with the information presented by William Snyder of Washington State University. He presented the talk “Spatiotemporally Distinct Natural Enemies Have Synergistic Effects on Shared Prey.”
What Snyder’s team is looking at is when beneficial insects are around pest insects but have not been killed, the pests are more likely to be killed by beneficial fungus or beneficial nematodes. They think the beneficials stress the pest, making them more susceptible to the pathogens.
Also, researchers from the University of Florida stressed for thrips management the importance of conserving native beneficials. They have found that by spraying pesticides for western flower thrips it actually causes more western flower thrips problems in the long run. They said it is better to use spray products that are soft on the beneficials, and to limit those sprays so native beneficials can get to work. They also discussed the many different native species of thrips and how they can outcompete western flower thrips.