Black Swallowtail - Alabama Butterfly Atlas

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Black Swallowtails are common, widespread, but often overlooked residents of Alabama's natural and suburban areas. This species is one of the few whose caterpillars are encountered more often than adult butterflies. Many herb gardeners are familiar with the striped "parsley worms" that eat their herbs, but do not realize that they are larvae of the large black butterflies that visit their flowers.

Many of Black Swallowtail's native host plants are extremely poisonous, but its caterpillars can detoxify the chemicals. In very young larvae, the white "saddle" contains uric acid that may function to help protect the caterpillar from the phytochemicals it ingests. Older larvae are bright green with black dashes and yellow dots that form bands on each body segment. From a distance, this coloration is cryptic: it camouflages them with their environment. Viewed at close range, it may also be aposematic, using a classic combination of warning colors (black and yellow) to discourage predators. Broods from the spring and early summer typically form green chrysalides that are attached to green leaves or stems. This species spends the winter in the pupal stage, so as day lengths shorten, caterpillars are triggered to form brown chrysalides. They usually attach to something non-deciduous like bark or stone, which offers better stability and protection for winter months.

Adult Black Swallowtails are mildly distasteful because of the toxic host plant chemicals their caterpillars ingest. In addition to their own slight toxicity, females strongly resemble Pipevine Swallowtails and are considered part of the Pipevine Swallowtail mimicry ring. Males perch on tall grasses, shrubs, or small trees where they have a clear view of the surrounding area. From those vantage points, they periodically patrol for females.

Apart from the Pacific Northwest, Black Swallowtails range across the United States. In Alabama, they occur in every county.

Distribution and Abundance

A dot on the county map indicates that there is at least one documented record of the species within that county. In some cases, a species may be common throughout the county, in others it may be found in only a specific habitat. The High Count information shows the highest numbers recorded for this species as well as when and where they occurred.

The sightings bar graphs depict the timing of flight(s) within each of three geographic regions. Place your cursor on a bar within the graph to see the number of individuals recorded during that period.

The abundance calendar displays the total number of individuals recorded within each week of the month. Both the graphs and the calendar are on based data collection that began in 2000.

The records analyzed here are only a beginning. As more data is collected, these maps and graphs will paint a more accurate picture of distribution and abundance in Alabama. Submit your sightings to albutterflyatlas@gmail.com.

Sightings in the following counties: Autauga, Baldwin, Barbour, Bibb, Blount, Bullock, Butler, Calhoun, Chambers, Cherokee, Chilton, Choctaw, Clay, Cleburne, Coffee, Colbert, Conecuh, Covington, Crenshaw, Cullman, Dale, Dallas, DeKalb, Elmore, Escambia, Etowah, Geneva, Hale, Henry, Houston, Jackson, Jefferson, Lauderdale, Lawrence, Lee, Limestone, Lowndes, Macon, Madison, Marengo, Marion, Marshall, Mobile, Monroe, Montgomery, Morgan, Perry, Pickens, Pike, Randolph, Shelby, St. Clair, Sumter, Talladega, Tuscaloosa, Walker, Washington, Wilcox

Sightings in the past 5 years
Sightings in the past 5 - 10 years
Sightings more than 10 years ago

High count(s):

24 - Jefferson - 9/2/2018
21 - Shelby - 9/30/2019
19 - Shelby - 7/23/2020

View county names by moving the mouse over a county or view a map with county names

Jan				Feb				Mar				Apr				May				Jun				Jul				Aug				Sep				Oct				Nov				Dec
1	2	3	4	1	2	3	4	1	2	3	4	1	2	3	4	1	2	3	4	1	2	3	4	1	2	3	4	1	2	3	4	1	2	3	4	1	2	3	4	1	2	3	4	1	2	3	4
2			6	5	10	5	24	27	39	45	67	33	29	22	10	37	31	25	80	30	67	69	74	107	89	95	129	93	100	103	126	94	47	42	57	28	10	1	1	2		2				1	1

Habitat

Various open areas including weedy fields, pastures, roadsides, woodland edges, marshes, and gardens. Seldom seen in deep forests.

Host Plants

Black Swallowtails use a wide variety of plants in the Carrot/Parsley family as their caterpillar hosts. A member of the Citrus family, Rue, is also chosen.

In addition to the plants highlighted in blue below, these common herbs have also been documented as Black Swallowtail hosts in Alabama:

Parsley (Petroselinum crispum)
Dill (Anethum graveolens)
Bronze Fennel (Foeniculm vulgare)
Florence Fennel (Foeniculm vulgare azoricum)
Lovage (Levisticum officinale)
Rue (Ruta graveolens).

For more information about these plants, please visit the Alabama Plant Atlas using the links above.

Landscaping Ideas

Black Swallowtails are common visitors to gardens that include their host herbs and vegetables. Surprisingly, caterpillars are more frequently seen than butterflies! Plant enough host plants to feed your family and your swallowtails. Consider adding native carrot family members to your landscape: Common Golden Alexanders are wonderful landscape plants and provide early spring host opportunities.

Swallowtails are avid nectarers and are especially attracted to native wildflowers such as milkweeds (Asclepias spp.), Joe Pye Weeds (Eutrochium spp.), Purple Coneflower (Echinacea purpurea), blazing stars (Liatris spp.), and phloxes (Phlox spp.).