Many different kinds of beetles visit gardens. Some, such as the ladybug or the soldier beetle, are predatory and beneficial to gardeners. However, most orange-and-black garden beetles eat fruits or plants. Asparagus beetles, cucumber beetles, Mexican bean beetles and Colorado potato beetles are unwelcome and destructive guests.
Of the orange-and-black beetles, two are sometimes seen hunting among the garden’s leaves and flowers. Ladybug and soldier beetles are black-and-orange hunters of common garden pests. The ladybug is a small, round beetle varying in color from red to orange and toting black spots. The soldier beetle is orange to red, elongated to nearly rectangular. Both feed primarily on aphids.
Both kinds of orange-and-black asparagus beetles feed on tender new growth of asparagus plants. Common asparagus beetles sport red-to-orange bodies and black wings with six white- or cream-colored spots. Spotted asparagus beetles are solid orange with 12 black spots on their backs. Both insects are approximately ¼ inch long.
Spotted cucumber beetles are small insects, measuring 1/5 inch long. They range from green-yellow to orange in color and have 12 black spots on their wings. Spotted cucumber beetles feed on the leaves and blossoms of cucurbits. Striped cucumber beetles are larger insects, about 1/3-inch long, with a yellow-to-orange body draped with three black stripes. They feed underground on tender roots and stems, but will feed on above ground stems of older plants. Both varieties transmit bacterial wilt.
The Mexican bean beetle resembles a ladybug in shape but is solid orange in color and dotted with 16 black spots on their wings. These insects measure approximately 5/16 inches by ¼ inches and are a major pest of bean plants. Colorado potato beetles have cream-to-orange colored bodies and 10 black stripes running down their backs. These 3/8-inch long insects feed on peppers, eggplant, tomato and potatoes.