I found these adult and immature leaf-footed bugs congregating on a tasty thistle in a local park. The bright orange coloration of the nymphs warns predators that they might not enjoy the taste of the little guys. The adult bugs have another defense. Like stinkbugs, they have two thoracic scent glands, and can put out quite a strong, sickly sweet odor when disturbed.
Leaf-footed bugs belong to the family Coreidae. As you might guess, they take their common name from the leaf-like extensions on their hind tibiae. This family also includes members without such ornaments, collectively referred to as squash bugs. Leaf-footed bugs are ‘true bugs’ in the order Hemiptera and suborder Heteroptera. Like other hemipterans, they have sucking mouthparts, which coreids use exclusively for feeding on plant fluids. Adults in this group range in size from fairly small (1-2 cm) to some of the largest terrestrial bugs (over 1 inch), and can be quite impressive.