As the drought continues, so do the struggles of managing shot hole borer. University of California Cooperative Extension Horticulture Advisor Mary Bianchi said there’s a connection between the two. “These beetles are attracted to trees that are stressed. As the drought continues and more of our landscape and crop trees are stressed for water, they’re more attractive to these types of beetles,” Bianchi said. “It’s a question that I don’t know if we will ever be able to answer completely. Unfortunately, the introduction of the insect into California at a time where the host trees, which number into the hundreds for this particular insect, are already stressed is maybe part of the issues that we are seeing.”
Bianchi added that people are also accelerating that spread. “Transport, we suspect, is mostly by people, so being careful about moving wood is the number-one key to making sure we contain this pest as long as possible,” Bianchi said.