Aerial spraying, once used for eradication, was discontinued years ago because of the adverse effects on the ecosystem. No one has determined which one is making its presence felt this spring, said David Kellum, senior economic entomologist for the San Diego County Department of Agriculture. The last time large swarms were reported was in 1998, he said. Lazaneo said the insects are thriving because of wet and mild weather conditions. Mild weather allows more grasshopper larvae to survive to adulthood.
Wet weather means an abundance of tender green grasses and weeds to eat.
The grasshoppers swarm, migrating each time they exhaust their immediate food source, he said. But it's starting to dry up out there now, so it shouldn't last much longer. Reports of heavy swarms have come mostly from the area around Lake Henshaw, Lazaneo said, but Craig Forrester, a butcher at Don's Market in Santa Ysabel, said he has seen them near his home in Julian. For Carol Anderson, they can't go away soon enough. When I first saw the tons of grasshoppers, I kind of freaked.