This is a summary of a video posted on YouTube by Doug Tallamy, an entomologist and author of Nature’s Best Hope.
You are nature’s best hope.
There are millions of specialized interactions in nature. For example more than half of insects are pollen specialists. That means they can only access pollen from one particular family of plants. If that plant is not available, the insect cannot survive. With the shortage of insects goes the decline of birds and other wildlife. I am old enough to remember, that when driving in the summertime, collisions with insects were so numerous that the windshield had to be cleaned at every fill up.
There are many reasons behind the decline in insect species. Tallamy spends very little time enumerating them. Rather, he talks about the hopeful things that we can do. We can save nature and slow down the food web collapse. Indeed living with nature is the only viable option.
He talks about rebuilding nature where there are lots of people. In cities, rural residences, suburban yards, power line corridors, rail and roadside corridors, there are many opportunities to rebuild functioning ecosystems.
He urges that we start with the most important species. Flowering plants and native trees support a huge variety of caterpillars. And caterpillars transfer more energy from plants to other animals than any other plant eaters. For example, 96% of terrestrial birds require insects to feed their young. The caterpillars are essential as they are filled with nutrients and are easy for young birds to eat.
We must choose our plants carefully as 90% of insects are host plant specialists. For instance, if you want monarch butterflies you require milkweed. Native oak trees, in particular, are good at rebuilding the food web. Over 500 species of moth feed on oaks.
Tallamy has started a project called homegrownnationalpark.org. It’s mission is to restore biodiversity and ecosystem function. He points out that an area bigger than New England is devoted to lawns in the United States. Lawns are essentially food deserts. If half of those lawns could be converted to functioning ecosystems over 20,000,000 acres could be rehabilitated. That is an area bigger than the 10 largest US National Parks.
He lists the keys to success.
*Shrink the lawns. This can be done by homeowners individually, within the neighbourhood, or within a municipality.
*Plant keystone plants. 5% of native plants produce 75% of caterpillar food and 15% make up 90% of caterpillar food. Non-natives are relatively poor at supporting insect populations. He does not disparage non-natives (with the exception of invasives) but recognizes they are poorer at supporting the food web. It is the absence of native plants rather than the presence of non-natives that is the problem. While 70% native biomass is the ideal a minimum of 30% native is required.
*Kill the lights. If you must use lights at night, use motion sensor lights or convert to yellow bulbs as these do not interfere with nighttime flying insects.
*Do not use pesticides.
*Design insect friendly landscapes. A layered landscape with trees, shrubs and flowers provides an opportunity for insects to pupate in the leaf litter or underground. Beds around a tree provide great habitat.
Here is the link to find the video presentation. It is a fast paced, well illustrated and informative work.
Submitted by Don Farwell