IN THE PARK - Caterpillars

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SPICEBUSH SWALLOWTAIL (Papilio troilus)

Though Spicebush Swallowtails have been plentiful in the park, we haven't really seen many of their caterpillars in the park. The host plants for their caterpillars are Spicebush, Sassafras, Bays, and Camphor Tree. We haven't had of these plants in the park. With the addition of a pair of young Camphor Trees (Cinnamomum camphora) last year, we were happy to find multiple caterpillars this Spring behind the house.


female


Camphor, a plant not native to North America, native to East Asia, is a host plant in residential areas, where it is often a landscape or garden plant.


Spicebush Swallowtails usually lay their eggs on the bottom of the leaves of their host plants.


The young, freshly hatched caterpillars resemble bird droppings, which is a trait found amongst a few species of Swallowtail butterfly.


As the caterpillar grows, it loses the bird dropping appearance and usually turns green with large false eye spots, somewhat resembling a small snake.


The caterpillars are often found in refuges made by curling the edges of the leaves of their host plants with sticky silk.


The caterpillar may less commonly also be yellow or orange.


Like most Swallowtail caterpillars, they have an Osmeterium, as scent gland that resembles a snake tongue or horns, and releases an chemical odor reportedly repellent to other insects, a strong mix of Turpenes.


the chrysalis, which is usually held against vegetation by a line of silk


Though usually brown in color, the chrysalis may also be green or yellow.


an adult Spicebush nectaring at flowers

New In The Park - Caterpillars

Black Swallowtail (Papilio polyxenes)

Well, its been a relatively mild winter here in Houston, with few really cold periods. The cold snaps we had, though fairly cold for the region, didn't last for more than a few days at a time. This and the the current warm February and March weather has lead to early wildflower bloom and butterflies laying eggs weeks early. We already have Monarchs on the Milkweed and Gulf Fritillaries on the Passion Vines.

Something I noticed a few days ago were a few Black Swallowtail caterpillars on the Dill and Fennel plants in the park's herb garden. This isn't that common an occurrence in our park, regardelss of the early appearance, so its quite a pleasant surprise.


A close up view of 2 polyxenes caterpillars on one plant. The mother only lays 1 or 2 eggs on each larval host plant.


The Black Swallowtail caterpillar can extend its osmeterium when threatened. Only the Swallowtail caterpillars (there are man varieties of Swallowtail) have these. The osmeterium releases unpleasant odors when extended, and may help to visually shock a predator.


2 Caterpillars on the flower stalk of a Dill plant (Anethum graveolens)


Black Swallowtail caterpillars are always found on plants in the Carrot Family (Apiaceae), like this Green Fennel (Foeniculum vulgare) in someone's garden.


The chrysalis of a Black Swallowtail, which are much harder to find than the caterpillars.


Adult Papilio polyxenes mating


The very tiny egg of the Black on the leaflet of an Italian Parsley (Petroselinum crispum)

Another Winter Visitor to the Park

Today we spotted another winter migrant in the park, the BROWN THRASHER (Toxostoma rufum). A friend told me she had seen him earlier in the day, and I found him thrashing with his beak, looking for small invertebrates and seeds, through some dead leaves under bushes.


Brown Thrashers are related to Mockingbirds and Cat Birds, and can mimic up to 3000 calls of other animals.

Winter Migrants in the Park (UPDATE)

We just spotted a beautiful male SUMMER TANAGER (Piranga rubra) hunting bees next to the house yesterday. Usually we get a female in the park this time of year, but almost never a male. I hope he stays for awhile ( in lieu of flying down to Central America).

VOCAB ALERT!!!

Sexual Dimorphism: when males and females have a different appearance


Male Summer Tanager


Adult males are obviously red




Male in it's 1st Spring


Females are usually yellow




Okay, so there is a reddish color phase that
females sometimes exhibit, but they are never
as bright red as the males.

SOUTH FOR THE WINTER

When people say that birds "go South for the winter", Texas is one of those Southern destinations for birds. At the park, some of those winter migrants (birds that migrate here to spend the winter) have arrived. Here is a brief photo gallery of some of the current birds of winter.

YELLOW RUMPED WARBLER






ORANGE CROWNED WARBLER






PINE WARBLER






RUFOUS HUMMINGBIRD








YELLOW BREASTED SAPSUCKER


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