Written by Colleen Wolpert
Lepidoptera (Leps) is the word for an order of insects that includes butterflies and moths.
The life cycles of butterflies vary from species to species. Some live most of the year as an egg and others live most of the year as a butterfly. Many caterpillars eat in the fall and finish eating in the spring. Some species have one generation (i.e., brood) per year while others create multiple broods in a few short months. The overwintering stage is different for each species – egg, young caterpillar, middle instar caterpillar, full grown caterpillar, pupa / chrysalis, or butterfly.
Life cycles were captured at different moments in many of the submissions from the mating Promethea moths submitted by John Baumlin to freshly emerged butterflies. See the full series illustrated with the images of the Black Swallowtail by Diana LaBelle and Monarch by Sarah Darling-Jones.
This series by Diana LaBelle illustrates the three stages with the Black Swallowtail.
Silkmoths such as the Promethea must lay eggs on host plants as quickly as possible, because silkmoths do not feed as adults. All of their energy comes from the fat stored in their caterpillar stage. Once they burn off that fat storage their life ends. Therefore, it is important that they get the business of mating and egg laying done without distraction from our lights.
Leaving lights on for an extended period of time can trap them to the point of exhaustion. Once they slow down, they are more vulnerable to predators.
They are called silkmoths because they spin silk cocoons to enclose themselves before shedding their caterpillar skin inside to pupate. Most moths make cocoons that provide this added protection, but there are many species including most Sphinx moths (aka Hawkmoths) that include the Clearwings that pupate in a naked state in the leaf litter or just below the soil surface in an earthen cell.
The Snowberry Clearwing as submitted by Kelly Frederick Sweet is one of 3 Clearwing moth species we have in our area. Most likely to be seen are the Hummingbird Clearwing Moth with its pale colored legs and green-brown body and the Snowberry Clearwing Moth with its black legs and bumblebee-like body.
Butterflies pupate as a chrysalis which is what is exposed after the final larva exoskeleton is stripped away (aka skin shed or molt). It is what is inside rather than what is formed around the caterpillar.
In the fall, one can tell if a butterfly will emerge before winter or remain in its chrysalis until spring by looking at how it is attached to a surface. In Jessica Pack‘s photo of a Monarch chrysals, one can see that the cremaster is attached to its silk pad at only one point.
On the other hand, in Diana LaBelle’s photo of a Black Swallowtail chrysalis, there are multiple points of secured attachment including a girdle that looks like a sling. One can see the shed exoskeleton of the caterpillar below the chrysalis.
In addition to the difference in how they pupate, butterflies and moths differ in design. The main difference is their antennae which are used for smell and balance. Leps smell for food sources such as nectar in flowers, sap, and roadkill / dead things. They also smell plants to determine the preferred hostplants for their caterpillars which can be very picky about what they eat. One can crush dill and get a female Black Swallowtail to reverse her flight to locate one her caterpillars preferred plants. A caterpillar raised on dill is featured in Diana's Black Swallowtail image.
Antennae are also used to capture the smell of pheromones to locate a mate. Butterflies have antennae that either have a club on the tip or a bent elongated tip. Male moths have full feathery antennae and females have either restricted feathery antennae or threadlike antennae. The filiform antennae of beetles, bees, and some other insects are more segmented threads. This American Snout photographed by Renee DePrato shows the clubbed antennae indicating that it is a butterfly.
Love those Leps: Part 2
We received so many great images to support our lepidoptera blog that Colleen has chosen to split this blog into two parts. Check back next week for more interesting facts about moths and butterflies.
About the Author
Long-time lepidoptera enthusiast, Colleen Wolpert has introduced butterflies and moths into her practice as a Clinical Social Worker. Her ground-breaking methods of teaching children how to befriend butterflies has helped children and families to connect socially as well as with nature. Colleen has been very active with local natural history organizations, including Waterman Center, in many roles. She leads nature walks, gives talks, writes articles and has taught a number of butterfly and moth workshops. At her home, Colleen works to cultivate her own backyard habitat to provide an environment conducive to butterflies and moths throughout their life cycle.