Thistle Butterfly, Cosmopolitan, or Painted Lady Butterfly; no matter what you call them, the parade has been spectacular this year. This year has been a good year to see hundreds of butterflies fluttering around.
Painted lady butterflies, Venessa cardui, have been on parade for over a week. They have wing span of 2-2.5” that have an orange-brown upper side of the wing with a patch of white and black. When they fold their wings up, the underside has a black, brown, and gray pattern with several ‘eyespots.’ Painted lady butterflies lay single eggs on their host plant. The eggs hatch in about 7 days into a larvae, or caterpillar, that is yellow, black, and white with tufts of hair that feed for 2-4 weeks. The caterpillars form webs by tying the leaves together to create a protective area for them to feed. The caterpillars can be found on over 300 species of plants. Their favorites include thistles, hollyhock, aster, mallow, and some legumes like soybeans. The adults prefer nectar from flowers like asters, iron weed, joe-pye weed, and sedum.
The reason we are seeing so many painted lady butterflies is because they are currently migrating. The painted lady is called an irruptive migrant, which means that they migrate independent of any season or geographic patterns. The butterflies migrate from California to Mexico and the rest of the United States. High rains in those areas can cause a higher number of butterflies here in Nebraska. Some evidence suggests that the migration of the painted lady could be linked to the El Nino climate pattern. When painted ladies do migrate, they do so in large numbers. When the conditions are right, they migrate by the thousands. Nebraska Extension entomologist Jody Green says that the painted ladies’ migration could be 9,000 miles and span 6 generation.
This year would be a great year to consider becoming a citizen scientist. Citizen scientists are members of the general public who help collect data as part of a collaborative project with professional scientist. The Vanessa Migration Project is an opportunity for you to share your observations of Vanessa butterflies, like painted ladies. You are able to find out how they migrate and distribute themselves across North America each year. Observers and scientists are tracking the movements and seasonal changes in the butterflies distribution as their range expands northward in the spring and retreats southward in the fall. Researchers are also studying the date, location and flight direction of migrations of these butterflies. If you see Painted Ladies in your area in larger numbers, please become a citizen scientist and report on the iNaturalist project page, https://www.inaturalist.org/projects/vanessa-migration-project. For more information about the Vanessa Migration Project, visit: http://vanessa.ent.iastate.edu/node/10482
Don’t let this opportunity flutter by, take advantage of a really awesome phenomenon and help the scientific community while you are at it.
Elizabeth Killinger is the Horticulture Extension Educator with Nebraska Extension in Hall County. For more information contact Elizabeth at firstname.lastname@example.org, her blog at https://huskerhort.com/, or HuskerHort on Facebook and Twitter.