Although bees and butterflies get the most attention as flower pollinators, beetles actually make up the largest population of pollinating animals. Beetles are most commonly attracted to bowl-shaped flowers with exposed reproductive organs as well as white or dull-green blossoms that are open during the day with a strong fragrance and moderate nectar production.
Beetles pollinate sweet shrubs (Calycanthus sp.), attracted to the maroon to dark-brown, 2-inch-wide flowers by their spicy fragrance. Sweet shrubs are small deciduous shrubs that grow 4 to 7 feet tall and are commonly found growing along the coastal plains of the southeastern United States. Thanks to pollinating beetles, sweet shrubs produce globe-shaped, tan-colored fruit capsules that enclose a nut and are 2 to 3 inches long.
Beetles pollinate tree peonies, herbaceous peonies and hybrids of the two types. Peonies (Paeonia sp.) are unique in that they secrete nectar not only from their flowers but also from their leaves or stems. These "extrafloral nectaries" on the peony plants attract beetles because the nectar is even easier to access.
Beetles are especially attracted to the white magnolia (Magnolia sp.) flowers, especially the larger, easier-to-access blooms of the Southern magnolia (M. grandiflora) that can grow up to 12 inches in diameter with wide petals. Magnolia flowers also attract pollinating beetles with their flower fragrance, which can be rather strong.
Beetles are drawn to the spicebush's (Lindera benzoin) small yellow, open flowers that provide easy access to the nectar. Found along the eastern coastal states, the spicebush grows 8 to 12 feet tall and wide, forming a rounded, deciduous shrub. The spicebush has light-green, 3.5- to 5-inch-long leaves with smooth edges that turn golden-yellow in fall. In September, the spicebush produces scarlet-red oval drupe fruits that are about half an inch in diameter.
Goldenrods (Solidago sp.) bloom in autumn, attracting and providing nectar for pollinating beetles. Their long clusters of small yellow flowers in racemes attract all types of pollinating beetles but most commonly provide a meeting spot for the yellow and black goldenrod soldier beetles. The exposed blossom racemes provide easy climbing platforms for beetles as well.