Amorpha juglandis
In 3 days ~10%
Amorpha juglandis, the walnut sphinx, is the only species in the monotypic moth genus Amorpha, which is in the family Sphingidae, erected by Jacob Hübner in 1809. The species was first described by James Edward Smith in 1797.
It is native to North America, where it is distributed from the Atlantic Ocean to the Rocky Mountains in Canada and the United States. The wingspan is 45–75 mm. The adult moth is nocturnal, active mainly during the early hours of the night.
The caterpillar feeds on alder (Alnus), hickory (Carya), hazelnut (Corylus), beech (Fagus), walnut (Juglans), and hop-hornbeam (Ostrya) species. When attacked by a bird, the caterpillar produces a high-pitched whistle by expelling air from pairs of spiracles in its abdomen. This whistle is similar to the alarm signal produced by various bird species. One group of researchers in Montana hypothesized that this is a form of mimicry that functions as an antipredator adaptation to startle the bird, causing them to potentially reject the caterpillar.
Bura, V. L.; Rohwer, V. G.; Martin, P. R.; Yack, J. E. (2010). "Whistling in caterpillars (Amorpha... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Great Smoky Mountains National Park | 🇺🇸 United States | |
| 2 | Cumbres de Monterrey National Park | 🇲🇽 Mexico | |
| 3 | Shenandoah National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Austin | 🇺🇸 United States | |
| 2 | Dallas | 🇺🇸 United States | |
| 3 | San Antonio | 🇺🇸 United States | |
| 4 | Monterrey | 🇲🇽 México | |
| 5 | Houston | 🇺🇸 United States | |
| 6 | Washington | 🇺🇸 United States | |
| 7 | Toronto | 🇨🇦 Canada | |
| 8 | New York City | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Walnut Sphinx sighting in Washington on a given day, based on 9 verified sightings from GBIF citizen-science data. It is the 1256th most-seen of the 1807 insects we can rate there. Over three days the chance rises to about 10%, if each day is a fresh chance.
Any time of year
In every month with enough records, under 5% of wildlife watchers report a Walnut Sphinx in Washington on a given day, so our monthly data shows no clear season.
Between midnight and 3 am
Across all the parks we cover, that three-hour window holds the most Walnut Sphinx sightings with a recorded time, and about 6 in 10 of them come between 6 am and 6 pm: it is seen both by day and at night.
6th of 8
Of the 8 cities where we can rate Walnut Sphinx sightings, Washington ranks 6th at under 5%. The best odds are in Austin (United States, about 10%), Dallas (United States, about 10%) and San Antonio (United States, about 10%).
Same family: Sphingidae
The closest relatives of the Walnut Sphinx that you can see in Washington (family Sphingidae, Sphinx Moths) are Hummingbird Clearwing (about 10%), Catalpa Sphinx (about 10%) and Snowberry Clearwing (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Walnut Sphinx is recorded against all the insects logged in Washington (9 verified sightings), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
