One hundred thirty-six species belonging to 36 genera of the family Formicidae are recorded from the state of Indiana. This number has greatly increased from the previous count of 92 species in 1986 when the last checklist was created. Until recently, little to no work had been done on Indiana myrmecology. With ants rising in the ranks of household pests, a better understanding of which species are present, their diversity, distribution, abundance, and unique individual biology is needed to understand and treat the problem
Species level identification keys are provided for the workers of all the known species present in the state. Diagnostic characteristics that are useful in differentiating each species from other Indiana species are provided, as well as previous names and synonyms, taxonomy, biology, behavior, colony social and spatial structure, known North American ranges, Indiana distribution and range map, select references and materials examined, and unique or interesting comments
A separate key for the pest control industry is also presented to aid in pest management that keys out common species encountered on the job. It is provided both as a manual dichotomous key as well as an electronic interactive key
Various habitats were sampled, including remnant forests, agricultural fields, urban settings, parks, wetlands, bogs, state forests, and national forests. Rare habitats such as bogs and remnant oak forests produced a variety of common species as well as rare species like Formica ulkei and Aphaenogaster mariae, respectively, that are ill equipped to survive elsewhere. Other species such as Camponotus pennsylvanicus and Tapinoma sessile are quick to adapt and disperse and therefore are more common throughout the state in various habitats. Proceratum pergandei, Neivamyrmex nigrescens, and Polyergus breviceps are considered rare but may be under collected due to reclusive behaviors. The International Union for Conservation of Nature (IUCN) Red List contains six species of ants found in Indiana with a VU D2 status: Crematogaster pilosa Emery, Dorymyrmex insanus (Buckley), Lasius latipes (Walsh), Polyergus breviceps Emery, Polyergus lucidus Mayr, and Protomognathus americanus (Emery)
