Length: 8.5 - 9.5 mm
The Phymata species are the most commonly encountered Ambush Bugs in eastern North America. Two species are most commonly encountered in the region, Phymata pennsylvanica (shown here) and Phymata americana. The latter differs by having a continuously smooth margin of the connexivum, while P. pennsylvanica has a prominent notch on the fourth segment as seen in the photo at left.
Phymata Ambush Bugs are sit-and-wait predators that are well camouflaged on flower heads. When an insect comes within reach, they are quick to grab it with their massive forelegs. Despite their diminutive size they are seemingly fearless about grabbing bees and other large prey.
Right: Males of Phymata pennsylvanica are typically much smaller than females. They are also darker, though not always this dark. Even in the darkest males the legs and abdomen remain pale.
Punzalan et al. (2008) argue that evolutionarily speaking, darker males have had an advantage in warming more quickly in the sun, enabling them to find females and mate even under chilly conditions.
American Insects site