How To Tell a Good Bug From a Bad Bug

It’s hard to know which bugs in the garden are helpful and healthy and which ones will grow into unfriendly, garden-destroying predators.

The University of Connecticut Home and Garden Education Center offers weekly columns elucidating important topics, including this week’s column on how to treat friendly pollinators such as butterflies.

A first step in protecting young pollinators is to be able to recognize them. The photos, right, for example show a swallowtail larva with spots on its stripes; and a monarch butterfly larva with just stripes. Novice gardeners (and even relatively experienced ones) might not know that larva is another word for caterpillar — and might not know that these large striped caterpillars/larvae will someday grow into beautiful butterflies, especially if you can protect and nurture them.

Once you know how to recognize beneficial bugs, it’s helpful to know how to nurture and protect them.

UConn’s gardening columnist Dawn Pettinelli goes so far as to recommend planting a pollinator garden, with plants that have healthy and delicious pollen. 

The first thing you need to do, of course, is create a safe space in your early spring garden for eggs and nests.

“Leaving an undisturbed, bare patch of soil or pile of brush in your garden will provide habitat for ground-nesting and cavity-nesting bees,” Pettinelli says in her column.

The next thing to worry about after nests and eggs? Food.

“To encourage the presence of butterflies, it is essential to supply food for their larvae, also known as caterpillars,” Pettinelli says. 

“Monarch butterflies are considered specialists, meaning they only complete their development when feeding on one particular plant: milkweed. 

“A few native species of milkweed are butterfly milkweed (Asclepius tuberosa), common milkweed (A. syricacia) and swamp milkweed (A. incarnata). 

“Others, like the black swallowtail, feed on members of the parsley family.”

Knowing what these butterflies eat can also help you identify which caterpillars are living in your garden. If you have a lot of parsley and you see a fat, stripey caterpillar, look closely to see if there are spots as well; chances are that you’ve got swallowtail larvae growing big and strong on your herbs.

Find UConn’s list of Northeast pollinator plants at https://pollinator-resource-center/northeast.   

When you go to the garden center this spring, you can even purchase plants that will entice pollinators to come live with you. Pettinelli particularly recommends perennial plants because they definitely have pollen (which can sometimes be lacking in annuals that are bred for a particular look).

Pesticides should be strenuously avoided; don’t use them at home and check to be sure none have been used on your plants before you buy them (this is a factor in favor of shopping local; the staff at your favorite nearby garden center probably know more about the plants they’re selling than the average big box store employee). 

Native plants should be prioritized. In her column, Pettinelli says that, “The color and shape of a flower will influence the types of pollinators that will visit it. For example, bees are attracted to white, yellow and blue flowers while butterflies prefer blooms that are red, orange, pink and purple. 

“Native plants to incorporate into pollinator gardens include: Anise hyssop, Beebalm, Goldenrod, Moss phlox, New England aster, and Purple Coneflower.”

These two photos from the University of Connecticut Home and Garden Education Center show two types of proto butterflies (the monarch has just stripes, the swallowtail also has spots) that should be nurtured if you spot them in your  yard. Photo courtesy UCONN

Photo courtesy UCONN

These two photos from the University of Connecticut Home and Garden Education Center show two types of proto butterflies (the monarch has just stripes, the swallowtail also has spots) that should be nurtured if you spot them in your  yard. Photo courtesy UCONN