Introduction DrMetcalf provides online access to information on cicadas , leafhoppers , planthoppers , spittlebugs , and treehoppers , including a searchable bibliographic database for retrieving literature on these groups, which together comprise the group Auchenorrhyncha . The database includes nearly 12,000 early publications (1741-1955). Few electronic databases cover the early literature for any insect group. Because the focal groups are common and widespread, users may find the database helpful for retrieving many older works on insects in general. DrMetcalf also includes an overview of the group Auchenorrhyncha and each of its major subgroups.