To Catch a Cabbage White...On a Wing and a Prayer

To catch a cabbage white butterfly...

It was early October and a gravid praying mantis, almost ready to deposit her ootheca, was hungry.

She crawled behind a cactus in our yard, waiting for prey.

It did not take long. A cabbage white butterfly, Pieris rapae, fluttered down and made the fatal mistake of landing right next to Ms. Mantis. 

The rest, they say, is...dinner.

Cabbage whites are in the news now because UC Davis distinguished professor Art Shapiro is sponsoring his annual Beer-for-a-Butterfly Contest. If you collect the first cabbage white of the year in the three-county area of Sacramento, Yolo and Solano, you'll get a pitcher of beer, or its equivalent. 

Shapiro, a member of the Department of Evolution and Ecology faculty, has sponsored the “Suds for a Bug” contest since 1972 to determine the butterfly's first flight of the year. He launched the contest as part of his long-term studies of butterfly life cycles and climate change.  P. rapae is emerging earlier and earlier as the regional climate has warmed, said Shapiro.  "Since 1972, the first flight of the cabbage white butterfly has varied from Jan. 1 to Feb. 22, averaging about Jan. 20." (See Bug Squad for contest details.)

Note that the cabbage white butterfly is not an insect to treasure.  As a caterpillar, P. rapae is a major pest of cole crops such as cabbage. UC Statewide Integrated Pest Management Program (UC IPM) says the cabbageworm is active throughout the year in California. "Cabbageworm larvae chew large, irregular holes in leaves, bore into heads, and drop greenish brown fecal pellets that may contaminate the marketed product. Seedlings may be damaged, but most losses are due to damage to marketed parts of the plant," according to the UC IPM website.

Indeed, if you grow cole crops, you're probably ecstatic about a praying mantis nailing a pest.

This mantis is a Stagmomantis limbata, as identified by Lohit Garikipati, a UC Davis alumnus studying for his master's degree at Towson University, Md.

A predator and a prey.

On a wing and a prayer.