Australian Eucalyptus Leaf Beetle in California

While camping on Santa Cruz Island of the Channel Islands off the Santa Barbara coast of California, we began noticing that many of the Eucalyptus leaves in the campground area of Scorpion Cove were heavily damaged by something feeding on them (Picture 3). After searching for a while we found a brown mottled leaf beetle about 5 mm long, often coated in sticky gum residue, on leaves, tree trunks, picnic tables and on the ground. We also found larvae and prepupal larvae on the trunks of the Eucalyptus trees (Picture 5). In addition, we found a very similar colored Orb Weaver Spider feeding on the beetles from webs within the cracks and crevices of the tree trunks (Picture 6). These beetles were more active at night, which is when we first found them.