The Other Pollinators

Posted on 19. Jun, 2015 by in Grays Corner, Recent News

Pollination is a process that is of enormous importance to humanity.  Food crops, trees, and ornamental plants all ultimately depend, in order to reproduce, on the transfer of pollen grains from one plant to the next. In some cases, this pollen is carried by the wind, but the most successful groups of flowering plants rely on animals to carry their pollen. These animals are called pollinators. The most familiar pollinators are, of course, the bees. Honeybees, bumblebees, and a variety of less well-known types all play vital roles in pollinating a huge array of flowering plants. However, they are by no means the only pollinators in the world, or even here in Davidson.

The most familiar of these other pollinators, of course, are the butterflies and moths, which are as renowned for their bright colors as they are for their services as plant pollinators. Butterflies and moths have a coiled feeding tube, or proboscis, that allows them to siphon nectar from the flowers on which they feeds. They are not as efficient pollinators as bees are, and fewer species of plants rely exclusively on them for pollination. Many gardeners, as a matter of fact, plant “butterfly gardens”—beds of plants devoted to use by butterflies and moths, whether providing nectar for them or serving as food for them in their caterpillar stages.

Another group of insects that performs underappreciated work as pollinators are those relatives of the bees, the wasps. Most wasps perform incidental work as pollinators at best, but there is one family that is, in fact, the sole pollinators of a major food plant—the fig wasps. Female fig wasps burrow into fig fruit to lay their eggs, pollinating the tiny flowers that line the inside of the fruit as they do so. After laying her eggs, the female fig wasp dies, but her eggs develop inside the fig and hatch into new wasps that eventually fly off to find new figs.

Flies and beetles are two other groups of insects that, while not normally thought of as pollinators, perform important pollinating duties. However, not all pollinating flies and beetles are nectar-eaters. Some are, such as hoverflies, bee flies, flower beetles, and even male mosquitoes. Others, though, more typically feed on dung, refuse, and the bodies of dead animals. To encourage pollination by these animals, some plants have evolved flowers that mimic the appearance and smell of the flies’ natural food. Most of the plants in this second group live in the tropics, but there are some, such as the pawpaw, that live here in Davidson.

No discussion of the diversity of pollinators would be complete without a mention of the most successful group of vertebrate pollinators—the hummingbirds. Many people seem to think of hummingbirds as eating sugar water from red plastic feeders, but in their natural habitat, they are significant pollinators of a number of plants. Hummingbirds are especially fond of red flowers and flowers with long, narrow “trumpets.” Here in Davidson, there is only one species of hummingbird, the Ruby-throated hummingbird. Others, however, live farther west, and the group achieves its greatest diversity of all in South America.

The role pollinators play in their world cannot be understated. Nearly every terrestrial ecosystem ultimately begins with flowering plants, and it is with the aid of pollinators that this dominance has become possible. And, because so many flowering plants are important to human, the existence of pollinators serves as a reminder that humans are never truly outside nature.

Tags: , , ,