Monday, June 20, 2016

National Pollinator Week

A bumblebee, sweat bee, and orange-spotted mint moth all feeding on a native Green-headed Coneflower. 

     Happy National Pollinator Week! To help celebrate, I hope to post about a pollinator each day for us to learn about and appreciate. But first a bit on pollinators in general. There are over 200,000 species of pollinators worldwide. These include such animals as bees, wasps, butterflies, moths, flies, beetles, and hummingbirds. We owe them much, as it is often said that one out of every three bites of food we enjoy is due to the direct actions of an animal pollinator. In fact, three quarters of all plants regardless depend on animal pollinators in order to reproduce. 
     When thinking about planting things to benefit our pollinators who benefit us so often, it is most important to consider the use of native plants. Some studies show that native plants are four or more times more attractive to native pollinators than exotic plants. This of course makes perfect sense since these plants and animals evolved together, sometimes to the point that one cannot exist with out the other. 
     So the most important consideration is to plant plants that are locally native. These plants are not only adapted to grow in this type of habitat, but are what the pollinators have been using for thousands of years. It is always best to use straight wild species, rather than cultivars or nativars which have been selected for certain traits. When we plant a flower that has been bred to appeal to us through a novel color or look, it may not have the same appeal to the pollinator its parent plants originally evolved with. What we think might be more attractive often isn't the case with the pollinator, some of which see flowers through different spectrums or look for certain traits in them. This is especially true of plants bred to have double flowers or blooms with extra large petals, since they often sacrifice nectar/pollen for the extra showy flowers.
     Finally something to consider are the multiple uses you get with native plants. Many exotic plants may have a pretty flower that may (or may not) provide nectar for a short time each year while blooming, but it otherwise provides little habitat for pollinators or other native wildlife. Take the Chinese Aster (Callistephus) for example. It is a pretty flower, comes in many color forms and is widely planted (and escaped and naturalized into some areas). The blooms on some varieties provide some nectar and pollen to a few pollinators for a short bloom time each year. But only two species of caterpillars have been recorded as feeding on it. It is for the most part and for most of its plant life a barren habitat for wildlife, taking the place of what might have been a much more beneficial native plant.

A Pearl crescent Butterfly feeds on a native Orange Coneflower, but only because its caterpillar had a native aster to feed on, the only thing the caterpillars can eat.

     Contrast that with one of  our many colorful and attractive native aster species, many adapted to a variety of growing conditions. Now you have flowers that not only provide attractive flowers for the garden and a similar look, but also serve a habitat function. In addition to pollinators visiting them, most also supply seeds for birds such as finches and sparrows. But 109 different caterpillar species have also been documented feeding on them. These in turn feed the vast majority of our nesting native birds (97% of terrestrial birds feed on insects, particularly during the nesting season, most of which are caterpillars) and most of the 17 bat species found in our region (all of which are insectivores and many of which prefer moths over other insects). 
     So you can see how something as simple as choosing a native plant species can not only serve to provide for pollinators, but then serve other habitat functions as well. So this National Pollinator Week, enjoy the pollinators in our gardens, farms, and parks. If you're able to, include locally native plants in your gardens. This way you too can help the pollinators who are always helping us. 

Three Tiger Swallowtail Butterflies, Virginia's state insect, feed on a native Buttonbush. Nineteen species of caterpillars feed on the plant itself and many birds eat the nutlets.  

1 comment:

  1. More determined than ever to plant and promote native!