For past quarter century, hundreds of volunteers have fanned out across eucalyptus groves and fir forests to count monarch butterflies, annual tallies that indicate the relative health of the bugs that pollinate fruits and flowers, nuts and vegetables. They are the canary in the coal mine, so to speak, for the damaging use of pesticides and herbicides, the loss of weeds that feed beneficial insects, and the severity of winter storms. All these could be reasons why the 2023 Western Monarch Count found about 100,000 fewer monarch butterflies than in 2022, the Xerces Society for Invertebrate Conservation announced on Tuesday.