Author Archives: Kristin S.

What’s Hiding in Your Leaf Pile?

Autumn leaf piles mean different things to different people. If you’re a child, leaf piles invite jumping and hiding and all sorts of fun. To many adults, all of those autumn leaves must be raked, blown, piled, chopped, dragged, or somehow transported to another place, anywhere that is not our lawn.

But if you’re a nature lover, a pile of dead leaves is teeming with life! For many creatures, leaf piles are places to hibernate, hide, hunt, scavenge, and survive. Look what I found last year while digging through leaves:

Giant Leopard Moth Caterpillar

Giant Leopard Cat - Nov 2012(small) (2)This gorgeous caterpillar curls up in a ball when disturbed, revealing bright red bands in between black bands of bristles. It hibernates in the same curled-up position under leaves, loose bark, and logs. Next summer, it will transform into a white moth with black spots, somewhat resembling a Dalmatian puppy.


A Woolly Bear Caterpillar

Raking Leaves - Nov 2012 WB(cropped) (2)We frequently see this orange- and black-bristled caterpillar crossing roads in autumn to find a hibernation spot. The woolly bear hibernates under leaf piles, logs, and rocks and will emerge in the spring to feed again before transforming into the brownish, less vibrant Isabella Tiger Moth.


Sowbugs and other decomposers

Sowbug Sowbugs, which are crustaceans rather than insects, have 12 legs and 7 armored plates, reminiscent of ancient creatures. Sowbugs hide in damp places, like piles of leaves, and feed on decaying organic matter. Given enough time, sowbugs will eventually convert your leaf pile back into soil.


What can we do to protect these fascinating creatures?

Here are some steps to encourage creatures like those pictured above. You may not find all the ideas practical, desirable, or applicable to your situation and that’s fine. Use what works for you.

  • Rake as few leaves as possible. In my yard, I only rake a central grassy area, leaving leaf litter in the flower beds and yard edges. Sure, it’s not as attractive as mulch, but it works to keep down weeds and it provides habitat for cool creatures.
  • Be gentle. If I find a hibernating creature while I’m raking, I move it to a protected spot in a leafy area of my flower beds. For any creatures I’ve missed, I gently rake leaves onto a sheet and deposit them in a nearby wooded area, hoping they’ll emerge in the spring unharmed.
  • Create a “pile of life.” When my children were younger, we created a huge pile of leaves each fall that we let sit year round. Every few days we would check the pile to observe all the natural drama. We found sowbugs, worms, fungal strands, and millipedes. One time we even chanced upon a ring-necked snake chasing a toad. Consider creating your own “pile of life.”

By Kristin Steinmetz, teacher naturalist at Broad Meadow Brook Wildlife Sanctuary in Worcester.

The Secret Life of a Giant Silk Moth

Cecropia MothIf you’re under the impression that moths are dull creatures who eat holes in sweaters, you haven’t encountered a giant silk moth. Luna moths, Promethea moths, Polyphemous moths, and Cecropia moths are all native silk moths of the subfamily Saturniinae.

These amazingly large, stunningly beautiful moths are found throughout Massachusetts, but we rarely see them. Flying mostly at night and spending much of their lives as caterpillars and cocoons, these moths fly under the radar. Observing one in action is always a WOW experience.

Life Cycle of The Cecropia Moth

In late May and early June, adult Cecropia moths (pictured above) emerge from their cocoons. With a wingspan of 5 to 6 inches, the Cecropia moth is the largest moth in North America. Adults are born without mouth parts, do not feed, and have one job: to mate and reproduce. Males have large feathery antenna, which can pick up the scent of a female from a mile away.

After mating, females lay more than a hundred eggs, usually in small rows on the underside of leaves. Around 10 to 14 days later, tiny black caterpillars emerge. The caterpillars are eating machines and feed on the leaves of many common trees including cherry (a favorite), sassafras, lilac, ash, apple, poplar, and willow.

Cecropia Eggs

The caterpillars go through 5 instars (i.e., skin sheddings), and grow very large. By the 5th instar they’re often at least 4 inches long and thicker than an adult thumb. They are also remarkable looking, with a frosted green coloring and red, blue, and yellow knobs extending from their bodies. Children often remark that it looks like ladybugs are riding on the caterpillar’s heads!

Cecropia Caterpillars - Cara Yacino

The caterpillars have many enemies and mortality rates are high. After weeks of eating and growing, the rare caterpillar that has successfully reached the 5th instar is ready to cocoon. On a branch or twig, the caterpillar will spin a rough, brown, spindle-shaped cocoon. The caterpillar will spend the winter in the cocoon, transforming into an adult moth, ready to emerge in late spring.

Cecropia Moth Cocoons

Status of Cecropias

Sadly, Cecropia moth numbers appear to be in decline due to habitat loss, pesticide use, and parasitism by a tachinid fly introduced to control the Gypsy Moth. (See Boettner et al, 2000). Maintaining a pesticide-free yard full of native plants and natural spaces is one way to help these amazing creatures. Some people go a step further and raise silk moths to increase their numbers, a labor-intensive and rewarding experience.

Learn More

Join a mothing or insect program at a Mass Audubon wildlife sanctuary near you.