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One Cool Cat

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spicebush swallowtail_side spicebush swallowtail
Sometimes instead of you searching for wildlife, the animals drop out of the sky and come to you. Perhaps something startled this little guy or it simply lost footing and dropped from the leaves above, landing at my feet.  To my surprise, it started rearing up its head to resemble an intimidating snake. This snake mimicking cat is a Spicebush Swallowtail butterfly caterpillar, Papilio troilus. The beautiful butterfly is mostly black with ivory spots along the bottom and blue (female) or blue-green (male) scales above those spots. The hindwings have a small splash of orange, while the ventral hindwings have two rows of orange spots (See pic here). This is a common species found in yards, fields, woodlands, and along roadsides. The adults frequent many native flowering plants, but they seek out two native plants to lay their eggs. These two main host plants are spicebush (Lindera benzoin) and sassafrass (Sassafras albidum). Each tiny individual egg (~1mm) is laid on the underside of the leaves of the host plant and can develop into a small brown and white caterpillar. The caterpillar will munch its way through the leaves and then molt into a larger sized larva. These larval stages are called instars, and the first four brown and white instars can be mistaken as bird droppings. The fifth instar is the one shown in the picture, with remarkable false eye spots and patterns to mimic a snake. Another amazing adaptation they have is to use silk to roll a leaf up around them and hide within a leaf shelter. Upon nightfall, they will come out and eat as much as possible before hiding again the next day. The caterpillar will molt one last time and become larger and more yellow. It then searches for a place to pupate and will build its chrysalis. Depending on the time of year and photoperiod (day length), the pupa will be either green or brown in order to mimic a green leaf during summer or a brown leaf to overwinter. Keep an eye out for the many life stages of this incredible little animal on your next hike.

~Tracy