The numbers of bee species by family and per checklist study in Pennsylvania. Blue portions of bars represent the number of species reported in the previous checklist (Donovall and vanEngelsdorp 2010); orange portions of bars denote data from our study. The number inside the blue portion of each bar represents the number of species retained from the previous checklist. Numbers with “-” and enclosed in parentheses indicate taxa removed from the state checklist due either to unverifiable records or synonymy. The numbers with “+”, either inside the orange portion or adjacent to the end of each bar, signify new state species records. The families rank from least to greatest number of species as follows: Melittidae (4 spp.), Colletidae (24 spp.), Megachilidae (81 spp.), Andrenidae (100 spp.), Halictidae (110 spp.), and Apidae (118 spp.).