Steve Glynn photo’d this Henry’s elfin at Bevan WMA (CUM) on March 29 last year, close to its average first emergence date of March 28. The first report last year was on March 25. The species is currently about two weeks overdue for 2018.
I unplugged the heaters from the yard’s bird baths the other day.
Wishful thinking!
Both were frozen solid this morning.
Needless to say, 2018 has been a late-starting butterfly year.
As of noon, today, April 11, SJBP observer/reporters have found only eight or nine species (depending on how we count the azures):
mourning cloak, question mark, eastern comma, spring azure, orange sulphur, blueberry azure, holly azure, cabbage white, and American snout.
Local weather forecasters are promising temperatures climbing into the 60s tomorrow, however, and — can it be true??– temperatures in the 70s over the weekend.
Which other species can we hope to see soon?
I looked back over ten years of first reports to calculate average early-emergence dates for the butterflies that usually appear by April 20th or so but haven’t yet been reported this year.
My calculations are rough and quick, and I wasn’t sure where to place clouded sulphur and red admiral in the sequence as some of our first reports were likely late flyers from the previous year. Both could appear soon. Please let me know if you note any other species missing — or see any errors.
Henry’s elfin: March 28 (average first report date). Has first emerged in March in five of our ten years — and before April 11 (today’s date) in all ten years. Latest first report: 4-9-14.
Eastern tailed-blue: April 2 (average first report date). Has first emerged in March in four of our ten years — and before April 11 in six of our ten years. Latest first report: 4-24-15.
Eastern pine elfin: April 5. Has first emerged in March in three of our ten years — and before April 11 in six of our ten years. Latest first report: 4-21-15.
American lady: April 5: Has first emerged in March twice in our ten years — and before April 11 in seven of our ten years. Latest first report: 4-15-15.
Falcate orange-tip: April 7. Has first emerged in March in two of our ten years — and before April 11 in six of our ten years. Latest first report: 4-16-15.
Dave Amadio photographed this falcate orange-tip at Riverwinds (GLO) on April 9 last year. Our first report in 2017 was on April 4. It’s another species overdue for 2018.
Juvenal’s duskywing: April 8. Has first emerged in March in two of our ten years — and before today’s date in four of our ten years. Latest first report: 4-17-09.
Frosted elfin: April 10. Has been first reported in March three times in our ten years — and before April 11 in four of our ten years. Latest first report: 4-24-13.
Eastern tiger swallowtail: April 11. Has first emerged in March once (3-31-16) — and before April 11 in four of our ten years. Latest first report: 4-19-14.
American copper: April 12. Has first emerged once in March (3-28-12) — and before April 11 in six of our ten years. Latest first report: 4-28-15.
Pearl crescent: April 15. Has first emerged once in March (3-19-12) — and before April 11 twice in our ten years. Latest first report: 4-30-15.
Black swallowtail: April 18. Has first emerged once in March (3-17-12) — and before April 11 three times in our log’s life. Latest first report: 4-30-15.
Wild indigo duskywing: April 18. Has first emerged once in March (3-30-12) — and twice before April 11. Latest first report: 4-29-17.
Horace’s duskywing: April 19. Has emerged once in March (3-23-12), the only time our first report came before April 11. Latest first report: 4-30-15.
Spicebush swallowtail: April 21. Has first emerged once in March (3-28-12) and twice in May. Latest first report: 5-7-09.
Sleepy duskywing: April 22. Has first emerged once in March (3-29-12) and before today’s date in two of our ten years. Latest first report: 5-7-09.
Keep exploring, everyone!
Jack Connor
Jen Bulava photo’d this Juvenal’s duskywing on April 9 at Wharton SF (BUR) last year. Our first report was on April 2. Its average first date of April 8 suggests it should emerge very soon.
This American copper, photographed by Chris Herz at Riverwinds (GLO) on April 14 was flying close to the species’ average first report date of April 12. Will someone find one in the next week?
Jack- Thanks for putting this concise guide together as we prepare for upcoming explosion of species.