Large numbers of sugarberry trees are dying in parts of Georgia and South Carolina, but it remains unclear what is causing this problem. USDA Forest Service scientists at the agency's Southern Research Station studied a native but poorly known beetle, Agrilus macer, that is often found attacking dying sugarberry trees in very high numbers. Egg mass densities as high as 13 eggs per square inch were observed on trunks, branches, and exposed roots of dying trees; however, not all dying sugarberry have been attacked by this species, and some trees are capable of overcoming attacks. The egg laying habits of the beetle were found to be extreme among known species of its genus, with females laying groups of 17 eggs on average. The eggs are then covered with a protective cap. Why they do this remains unknown, but it is possible that larvae are better able to overcome host defenses if they attack as a group. Fungi isolated from discolored sapwood around larval galleries did not cause defoliation, dieback, or mortality of sugarberry in inoculation trials. Their findings suggest that Agrilus macer is a secondary pest on sugarberry and does not transmit harmful fungal pathogens, eliminating it as a primary causal agent for sugarberry decline and suggesting further investigation of other pests and pathogens.