Perfume and Pollination 2 - The Rose

Fragrance has long served the interests of roses by attracting both natural pollinators and human propagators. The scent of our native Halibut Point rose rivals the best of Syrian fragrances.

Virginia rose, Rosa virginiana

Compared to the privet, rose fragrance takes the high road emphasizing subtlety over quantity.

Small Carpenter Bee, Ceratina sp

Our rose draws admirers close with brightly colored petals, where its perfume seals the enchantment. This pattern favors us visually-oriented humans. It works well for various bees too, although bees can undoubtedly detect the fragrance at a greater distance than our own smell-deficient species.

Bicolored Striped-sweat Bee, Agapostemon virescens

Bees of many descriptions fly to the flowers. They satisfy their nutritional needs and carry pollen from the male stamens of one blossom to fertilize the female pistils of another. Erotic elements weave through all parties to the story ‒ flora, fauna, and civilization.

Masked Bee, Hylaeus sp.

Bumblebees can be frequently recognized among insects drawn to the alluring rose. Yet I am puzzled at never having seen a honeybee in its vicinity. That curiosity calls for further exploration.

Two Miner Bees,  Andrena sp., and a Carpet Beetle, Cryptorhopalum triste

Within the vastly diverse insect world only one other order, Coleoptera‒Beetles‒seems to have in important role in the pollination of roses at Halibut Point.

 Coleoptera derives from two Greek words, koleos meaning sheath and ptera meaning wings. Beetles are distinguished from other insects by their front pair of wings (elytra) modified into a protective, often colorful cover over their membranous pair of flight wings. To fly, beetles have to hold their elytra outstretched. They characteristically have chewing mandibles rather than piercing, sucking mouthparts.

Tumbling Flower Beetle 1, Falsomordellistena pubescens

Coleoptera, with about 400,000 species, is the largest of all orders. It constitutes almost 40% of described insects and 25% of all known animal life-forms.

Tumbling Flower Beetle 2, Mordella marginata

Even the tiniest species are wonderfully diverse, complex, and integrated to their circumstances.

Long-horned Flower Beetle, Strangalia luteicornis

The flattened dish of the Rosa virginiana inflorescence follows the shape of most beetle-pollinated flowers. Its pollen is easily accessible and the plant's ovaries are relatively well protected from the biting mouthparts of beetles. 

Rose Curculio, Merhynchites bicolor

Rose curculio weevils drill holes and lay eggs in developing buds where their larvae feed on the reproductive parts of the flower. These depredations may still serve the ultimate purpose of cross-fertilization as pollen-covered beetles move from plant to plant. It would be interesting to chart the balance of losses and gains from their activity.

Hairy Flower Scarab Beetle, Trichiotinus affinis

Some beetles disfigure flowers by chewing holes in the petals. But petals are not an end in themselves. They exist to bring insects in contact with pollen. In the case of roses, fragrance lies within the petals themselves. They tempt, and are tempting to some tastes. 

Roses concoct exquisite scents from an array of more than 300 chemical compounds, of which only 4 produce most of the fragrance. According to Flower Power Daily.com, perfume harvesters have to collect as many as 60 roses to distill just one drop of essential oil and 250 pounds of petals are required to make an ounce of it. Clearly, in its own sphere, each flower orchestrates its grand purposes economically with only the tiniest potions released to the breeze.