In Praise of insects!

I’m old enough to remember having to scrape the bugs off the windshield every time we filled up with gas in the summertime. Insects were numerous, especially in the evening. Where did they all go?

I also remember an advertising slogan that said, “The only good bug is a dead bug”. Wrong! Something like 80% of our food plants require insects for pollination. Only about 1% of insects are pests. 

Many products that we use in daily life are produced thanks to insects. Honey, silk, dyes and some medications are just a few. The survival of many plants requires a specific or small group of insects. Pollinators are worth billions annually to the food industry. Like the proverbial canary in the coal mine, insect numbers are indicators of environmental health. Many birds require a healthy insect population in order to survive. Arial insectivores,  such as swallows and chimney swifts have seen drastic reduction in their numbers. We think of chickadees as seedeaters but a clutch of chicks requires thousands of insect caterpillars brought to the nest. Insect numbers globally are down 25% since 1990. This is based on a 166 studies
and 1700 sites around the world.

The dilemma for Gardeners is how to maintain a healthy environment and at the same time limit the damage done by insects.

One way is to tolerate some amount of damage. For instance, we have a goatsbeard that gets eaten down to the stems every year. I used to spray it with neem oil until I realized the little caterpillars were feeding the birds. Now I just enjoy the plant in the spring and let nature take it’s course. On the other hand we have a 30 year old dwarf scented viburnum standard that I don’t want to lose so I do spray it with neem to discourage the caterpillars.

You can encourage natural predators such as frogs, toads and birds by building a water feature or bird or bee houses or by planting hedges or windbreaks which act as refuges for them. Or a simple water dish with a few flat stones will help. Minimizing tillage and leaving plant stems out over the winter also provides food and safety. Planting native trees and shrubs will provide great sources of food for insects while the damage will be minimal as these species have spent thousands of years learning to coexist. Members of the oak, willow, cherry and birch family support the largest numbers of insects.

Floating row covers will protect squash, cabbage, cucumber and similar plants. I enjoy hand picking the potato bugs and Japanese beetles and red lily beetles. There are some websites which will help you distinguish beneficial insects from those you wish to discourage. and are two of them. Bugguide allows you to click on the shape to reduce the choices. There are also some phone apps which allow you to submit a photo and the artificial intelligence will identify the insect or at least reduce the possibilities.
To me, as a home gardener, working with nature instead of against it, is the

Happy gardening.

Submitted by Don Farwell