1 Digitalis medicines control irregular heart rhythms (called arrhythmias) by slowing the signals that start in the sinoatrial (SA) node. 2  This, in turn, reduces the number of signals that travel through the atrioventricular (AV node). 3  Fewer signals mean fewer arrhythmias.
June beetle (genus Phyllophaga), also called May beetle or June bug, genus of nearly 300 species of beetles belonging to the widely distributed plant-eating subfamily Melolonthinae (family Scarabaeidae, order Coleoptera).
Definition of JUNE BUG. : any of numerous rather large leaf-eating scarab beetles (subfamily Melolonthinae) that fly chiefly in late spring and have larvae that are white grubs which live in soil and feed chiefly on the roots of grasses and other plants âcalled also june beetle.See june bug defined for kids.ADVERTISEMENT. any of numerous rather large leaf-eating scarab beetles (subfamily Melolonthinae) that fly chiefly in late spring and have larvae that are white grubs which live in soil and feed chiefly on the roots of grasses and other plants âcalled also june beetle. See june bug defined for kids. ADVERTISEMENT.