Early beetles appear to have been among the primary visitors of primitive flowering plants. An improvement over wind pollination, beetles likely played an important role in the evolution of flowering plants.



Many familiar North American plants are pollinated by beetles. For example, plants in the magnolia family, including the eight species that are native to the United States, have flowers that are specialized for beetle pollination. In fact, though magnolia flowers are often described as "primitive" (relatively unchanged from the ancestral type), some researchers have suggested that magnolia flowers are actually quite specialized and have evolved to promote nearly exclusive pollination by beetles. The beetles appear to be attracted by the odor of the flowers - which is sometimes described as unpleasant - as well as their color. They feed on nectar, stigmas, pollen, and secretions of the petals. Other insects appear to be unable to access magnolia flowers at critical times, while stigmas are mature or while pollen is shed. At least some magnolia species, including one species in Mexico, produce heat.



Odor, often foul or unpleasant, is thought to act as a primary attractant for many beetle and fly pollinators. Beetle-pollinated plants additionally produce heat. The odor may mimic a food source; the heat is thought to help spread the odor and/or provide a direct energetic benefit to pollinating insects