Yesterday I came home from work to find this impressively large spring fishfly (Megaloptera: Corydalidae: Chauliodes rastricornis) resting on my front door. As the standard US quarter above shows, this individual was about two inches in length.
These insects have aquatic larvae that live in relatively calm water littered with detritus. The larvae feed on decaying organic matter and prey on other arthropods. After fattening up they pupate and emerge as adults between April and June, depending on latitude.
In spite of their large jaws adults only feed on sugary substances like plant sap, if they feed at all. Adults only live for about a week and in that limited time they are far more concerned with mating than eating. This individual was a female, as evidenced by the serrated antennae. Males have pectinate (comb-like) antennae. After mating and laying her eggs near water this female would soon die, leaving the next generation in her stead.