Since the intentional introduction, release, and establishment of the lymantriid predator, Calosoma sycophanta (L.), in 1906-07 in the vicinity of Boston, MA, its range has continued to expand. Compilation of collection localities, all intentional releases in North America, and museum collection records permitted documentation of spread over time and a crude straight line estimate of the rate of dispersion, calculated at 6 km/year. Trapping and other collection records in recent years permitted an approximation of the current distribution, which now extends from southern Maine and all New England states south into Pennsylvania, Delaware, Maryland, and West Virginia. During 15 years of trapping at one New Jersey site and in the mid-Atlantic states, we collectively placed 3,792 traps in 253 locations. We captured 12,117 C. sycophanta, most of which were immediately released on location. Of those that were sexed (4,160), 74.3% were males. We recorded new state records for Delaware, Maryland, and West Virginia. Other species trapped include C. scrutator (200 specimens, most in New Jersey), C. wilcoxi (12, most in Delaware), C. frigidum(896, most in Pennsylvania) and C. calidum (22, most in Virginia).
