A Butterfly and a Bush: A Love-Hate Relationship

When a newly eclosed Western tiger swallowtail, Papilio rutulus, lands on a butterfly bush, the colors are striking.

The yellow and black butterfly contrasts well on the purple blossoms of Buddleja davidii.

While the majestic butterfly is widely loved, the plant, also called summer lilac, is not. It's considered an ecological threat and a noxious weed by the Invasive Plant Atlas of the United States: "Buddleja davidii readily invades disturbed sites and riparian areas. Although butterflies will use this plant as a nectar source their larvae cannot survive on it. By replacing native larval food source plants butterfly bush can have a negative impact on wildlife."

B. davidii is native to Sichuan and Hubei provinces in central China, and also Japan. The genus, Buddleja, is named for the Rev. Adam Buddle, an English botanist. The species name honors Father Armand David, a French missionary and explorer in China, Father Armand David, who was the first European to report the shrub, according to Wikipedia. It won the RHS Award of Merit in 1898, and the Award of Garden Merit (AGM) in 1941. 

Now nurseries are selling non-invasive hybrids,  with such names as "Lo and Behold" and "Blue Chip" and "Flutterby."

Nevertheless, who can resist photographing the Western tiger swallowtail as it stops to nectar on a butterfly bush?

Lo and behold...