UC Riverside’s Akif Eskalen pointed to a pattern of small holes in the bark of a majestic California sycamore tree growing in a Riverside park and lamented that it will be dead in about two years. The holes are the work of invaders from Southeast Asia, beetles smaller than a sesame seed that probably hitched a ride to the Golden State in packing wood. First discovered but misidentified in 2003 in Los Angeles County, the beetles have since infested at least 49 species of trees in seven Southern California counties, said Eskalen, a plant pathology professor.