Giant Swallowtail and Monarch

Subject: Is this a Giant Swallowtail?
Location: Fullerton (Orange County) CA
July 31, 2014 8:20 am
Here is a better photo of our overnight visitor. It landed on the night blooming jasmine at dusk yesterday and settled in for the night. To my surprise it is still there as of 8 a.m. It is quite large, at about 4″ across, warm black with striking yellow markings. When viewing from the kitchen window slightly above, there is a thin edge of yellow showing on the ‘shoulders’ so that it presents as a heart. It’s beautiful. Thank you for your wonderful website.
Signature: Likes Bugs

Giant Swallowtail
Giant Swallowtail

Dear Likes Bugs,
You are correct that this is a Giant Swallowtail, a relatively recent resident of Southern California.  The Giant Swallowtail is native to the eastern portion of North America, but the caterpillars, known as Orange Dogs, adapted to feeding on the leaves of orange and other citrus trees, and as the cultivation of citrus spread west, the range of the Giant Swallowtail followed.  We believe they first appeared in Los Angeles in the 1990s.  According to the Los Angeles Times:  “The giant swallowtail butterfly,
Heraclides (Papilio) cresphontes, is native to the Southeast. Since the 1960s, populations have spread west following a corridor of suburban development and the species’ favorite larval food source — citrus — through Arizona, into the Imperial Valley, then San Diego and north to Orange and Los Angeles counties. They’ve been sighted as far north as Santa Barbara and Bakersfield.  Numbers have surged since 2000, says Jess Morton, president of the Palos Verdes-South Bay chapter of the Audubon Society. Members have held a butterfly count at the same location, on the first Sunday in July, every year since 1991. According to their records, a single giant swallowtail was first seen in the South Bay in 2000. They counted 23 in 2007.”  According to the Kaufman Field Guide to Insects:  “Ranges throughout most of the east;  more limited distribution in the southwest, but has expanded into the Los Angeles basin within the past 20 years.”

Thank you so much Daniel. We have two tangerine trees, a lemon, a grapefruit, a valencia orange, and two washington navel oranges on our 8,500 sf lot. So yes, there is lots of citrus here for the larvae.
I found it so interesting that it settled on the leaves, spread it’s wings and went to sleep. It took off when the sun hit it at about 9a this morning. It is the first of that kind I’ve seen here (northern inland hilly Orange County – warmer than the coast.)
The Monarchs on the other hand, are plentiful. We have many milkweed plants for them and they put on a show – photo attached.
Thank you again for your help!
Nancy Rennie


Hi again Nancy,
It is our observation that Monarchs seem more plentiful this year than they have in recent years.

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