From the perspective of a plant, our primary objective is reproduction, and for many of us, that means attracting mobile partners to transfer pollen. The cornflower (Centaurea cyanus) is no exception. We have evolved a suite of characteristics specifically designed to appeal to a wide array of beneficial insects. Our very survival and proliferation depend on the successful visits of bees, butterflies, and other pollinators. Therefore, the answer to whether we attract these creatures is a resounding yes, and it is the result of a sophisticated evolutionary strategy.
Our most striking feature is our vibrant blue flowers, a color that is highly visible to bees. While humans see a pretty bloom, a bee sees a distinct target thanks to its ability to perceive ultraviolet light. The individual florets that make up each flower head are arranged in a composite structure, creating a large, flat landing platform. This is an open invitation, especially for larger insects like butterflies, who require a stable place to alight. The outer ring of larger, radiant blue florets acts as a bullseye, guiding insects toward the center where the true, nectar-rich tubular florets are located.
Visual cues are meaningless without a worthwhile reward. We offer a dual incentive system. Firstly, we produce nectar, a sugary liquid that serves as an energy source for bees and butterflies. Our nectar is accessible to insects with both long and short proboscises, making us an egalitarian food source. Secondly, we provide abundant pollen, which is the primary protein source for bees to feed their larvae. The pollen is prominently displayed on our anthers, easily collected by foraging bees as they move from floret to floret. This combination of accessible nectar and plentiful, high-quality pollen makes a cornflower patch an irresistible foraging destination.
While bees and butterflies are our primary targets for pollination, our appeal extends to other beneficial insects that contribute to a healthy garden ecosystem. The structure of our flower head provides excellent shelter for small predatory insects like hoverflies, lacewings, and ladybugs. These insects are the gardeners' allies, as their larvae consume vast quantities of common pests like aphids. By offering a safe haven and an alternative food source (some also feed on pollen), we help sustain a population of these natural pest controllers, creating a more resilient plant community.
Our strategy involves not just attracting beneficial insects, but supporting them throughout the season. Cornflowers have a remarkably long blooming period, often from late spring through to early autumn. This extended availability of resources is crucial for insects. It provides a reliable food source for multiple generations of bees and supports migrating butterflies like the Monarch that need fuel along their journey. For a beneficial insect like a ladybug, a consistent habitat means it is more likely to stay and reproduce, providing continuous pest control.
