According to Tallamy about 90% of insects native to the United States are specialists that "are adapted to find, eat, digest and survive on plant lineages that produce particular types of phytochemicals". Many plants in our landscapes are aliens from other continents and do not have the correct phytochemicals for native insects to eat them. As we rapidly loose our native habitat we need look at increasing the biodiversity of our own communities through using more native species where it makes sense. If we don't have the habitat for our native insects, then we in turn have less bird, reptile, and amphibian species that need insects to survive.
|Buttonbush, great nectar and host plant.|
Just because a plant is pretty (and drought tolerant,disease resistant, and has great form...and...) doesn't mean that it's a plant that supports native insects. Some plants may not seem exciting for insects but are an insect feast. Oaks can support over 500 species of butterflies and moths. Black cherry is right behind them with over 400 species. Personally I've started my own little credit system when I am doing landscape design. I can plant 'that' (example, butterfly bush that has little benefit beyond a nectar source to adult butterflies) if I plant one or two of 'those' (example, Buttonbush or New Jersey Tea which have great benefit to insects, caterpillars and adult butterflies). It certainly has made my design and plant choices more intentional, yet allows me to continue and enjoy some of those non-native species. More of Tallamy's thoughts and research on choosing plants here: http://bringingnaturehome.net/
|Butterfly bush, great nectar plant and poor host plant.|
Here is what I found while walking through the display beds this morning:
|Purple coneflower and bee|
|Milkweed leaf and green lacewing|
|Common milkweed and milkweed beetles|