Cabbage White Butterfly Gardens for North American Cabbage Whites

Summary: Drought, shepherd’s purse and Virginia peppergrass kill cabbage whites in planned or wild cabbage butterfly gardens of Canada, Mexico and the United States.

cabbage white butterfly (Pieris rapae) nectaring rough blazingstar (Liatris aspera): Dr. Thomas G. Barnes/University of Kentucky, Public Domain, via USFWS National Digital Library

Cabbage whites are visiting planned and wild cabbage butterfly gardens even though climate change threatens the lepidopteran's extinction by 2050, according to an entry Jan. 16, 2016, by Butterfly Conservation in Twitter.

The United Kingdom-based British charity brings worldwide attention to the effects of chemical controls and climate change on cabbage whites through A Gardener’s Friend or Foe? The Twitter entry considers replacing chemical controls with manual removals of the champagne-colored lepidopterans’ caterpillars from cabbage plants to diversion plots of wild mignonettes and nasturtiums. It describes cabbage whites as “drought sensitive insects” and “important pollinators” native to Eurasia and North Africa and naturalized in Australia, New Zealand and North America.

The plucky pollinators nevertheless emerge among the 59 species already sighted in the United Kingdom, according to entries Jan. 21, 2016, on the Butterfly Conservation website.

Cabbage whites frequent planned and wild white cabbage butterfly gardens throughout Canada, Mexico and the United States because of introductions into Quebec, Canada, in the 1860s.

Scientists give cabbage whites ecological classifications as generalists because of their tolerances of disturbed sunny habitats and open sunny woods and of diverse fast-growing, nutritious crucifers. Cabbage white butterflies have the ability to detoxify the herbivore-deterring glucosinolates (mustard oils) synthesized by crucifers even though they will die from eating selenium-rich mustard greens. The adult stage is incapable of sequestering mustard oils to repel vertebrate predators even though the larval stage repels such invertebrates as ants by secreting mayolenes.

Cabbage whites join checkered whites at waste areas even though the latter tolerates shepherd’s purse and Virginia peppergrass whereas the former favors garlic mustard and wintercress.

Typical life cycles and natural histories keep cabbage whites alive in planned and wild cabbage butterfly gardens throughout North America for 32 days to eight-and-one-half weeks.

Cabbage white butterflies live for 4 to 7 days as tiny yellow eggs that are deposited one at a time and that sport 12 lengthwise ridges. They may spend 14 days to 4 weeks as green caterpillars that have a light yellow stripe and that molt (shed their skins) through 5 instars. They need 8 days to 3 weeks to pupate into brown or green-colored chrysalises that can overwinter and start the adult stage in the following spring.

Maturity offers adult cabbage whites 6 days to 1 1/2 weeks to flaunt black-tipped forewings, black-dotted once each for males and two for females, and creamy undersides.

Cabbage whites promise arrivals of spring in their late February flights through planned and wild cabbage white butterfly gardens and of winter in their mid-November excursions. Cultivated and native crucifers qualify as hostplants for depositing eggs on leafy undersides whereas black-eyed Susan, buttonbush, dandelions, red clovers, violets and wild strawberry represent food. Adult cabbage whites relish nectaring on the same flowering plants that serve as larval food sources: black-eyed Susan, buttonbush, dandelions, red clover, violets and wild strawberry. The speedy strength in 1.7-inch- (4.32-centimeter-) long wingspans serves to help cabbage whites avoid and elude predatory earwigs, fireflies, lacewings, praying mantises, songbirds, spiders and toads.

Try moist, open, sunny lawn corners, roadside ditches and vacant lots as North American gardens if you regard iconic white cabbage butterflies as friends, not foes.

Cabbage white butterflies (Pieris rapae) are also known as small whites: BC @savebutterflies via Twitter Feb. 4, 2016

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

cabbage white butterfly: Dr. Thomas G. Barnes/University of Kentucky, Public Domain, via US Fish and Wildlife Service National Digital Library @ http://digitalmedia.fws.gov/cdm/singleitem/collection/natdiglib/id/7985/rec/2

Cabbage white butterflies (Pieris rapae) are also known as small whites: BC‏ @savebutterflies via Twitter Feb. 4, 2016, @ https://twitter.com/savebutterflies/status/695183590896828416

For further information:

BC‏ @savebutterflies. 4 February 2016. "Last Feb we had our first sighting of a Small White butterfly -- have you seen one yet?" Twitter.
Available @ https://twitter.com/savebutterflies/status/695183590896828416

Butterfly Conservation. 16 January 2016. "Cabbage White: Gardener’s Friend or Foe?” Twitter.
Available @ https://twitter.com/savebutterflies/status/688405434789658625

“First Butterfly Sightings 2016.” Butterfly Conservation > Butterflies and Moths.
Available @ http://butterfly-conservation.org/52/first-sightings-2013.html