Meet the Applegates (1990)

Giant praying mantises living in a South American jungle decide to move into suburban U.S. Disguised as humans, they are planning something. Could it be connected to Richard P. Applegate's (Ed Begley, Jr.'s) job in the power station perhaps? One day, Sally Applegate (Camille Cooper) forgets what she really is when she's with her boyfriend. Oops!