Chrysomela schaefferi (Leaf Beetle)
Credit: Alice Abela
about the species
Chrysomela schaefferi is found in Western North America, including Alaska and as far east as Manitoba. In California, it occurs from Santa Barbara to the Oregon border, but usually along the coast in cooler conditions. Adults show a color polymorphism, with darker brown forms typically found in cooler regions with more fog, and light brown forms occurring 20-40 miles inland. Both color forms are found in many populations. These beetles undergo only a single generation per year in California, and they co-occur with Chrysomela confluens and Plagiodera californica in many localities. Adults and larvae feed on willows. Like C. confluens, C. schaefferi belongs to the 'scripta' subgenus of Chrysomela.
why species was selected
This species shows evidence of thermal melanism, with darker forms most common directly along the coast and lighter forms inland. They are also restricted to areas with mild air temperatures. Their color differences and restricted range suggests that they are a good indicator of climatic conditions, and suitable conditions for them may decline as California experiences warmer, dryer conditions in upcoming years.
