Beewolf
Beewolves (genus Philanthus), also known as bee-hunters or bee-killer wasps, are solitary, predatory wasps, most of which prey on bees, hence their common name. The adult females dig tunnels in the ground for nesting, while the territorial males mark twigs and other objects with pheromones to claim the territory from competing males.
Sphecius speciosus
The males are more often seen in groups, vigorously challenging one another for position on the breeding aggregation from which they emerged, and generally investigate anything that moves or flies near them. It is not unusual to see two or three male wasps locked together in apparent midair combat, the aggregate adopting an erratic flight path until one of the wasps breaks away. The male wasp's aggressive behavior is similar to that of another robust insect of the area, the male carpenter bee. In both cases, while the males' vigorous territorial defense can be frightening and intimidating to human passersby, the males pose no danger whatsoever. Male cicada killers will only grapple with other insects, and cannot sting.
This ground-burrowing wasp may be found in well-drained, sandy soils to loose clay in bare or grass-covered banks, berms and hills as well as next to raised sidewalks, driveways and patio slabs. Females may share a burrow, digging their own nest cells off the main tunnel. A typical burrow is deep and about wide. In digging a burrow, the female dislodges the soil with her jaws and, using her hind legs, pushes loose soil behind her as she backs out of the burrow. Her hind legs are equipped with special spines that help her push the dirt behind her. The excess soil pushed out of the burrow forms a mound with a trench through it at the burrow entrance. Cicada killers may nest in planters, window boxes, flower beds or under shrubs, ground cover, etc. Nests often are made in the full sun where vegetation is sparse.