'Extremely fortunate' conditions bring caper white butterflies to Adelaide

Insect enthusiasts are welcoming the arrival of a surge of native butterflies to Adelaide amid wet weather conditions in Central Australia.

Kris Messenger from Bugs and Slugs, an invertebrate education service in Adelaide, said heavy rains further north had provided ideal conditions for caper white butterflies to thrive.

She said the white-and-black-tipped-winged insects generally rested on native and introduced caper plants as part of their move south for the summer, to escape the heat and limited food supply.

"It's all driven by the extremely fortunate weather conditions we've had inland," Ms Messenger told ABC News.

"(The caper white butterflies) complete this annual migration, which you might not notice in an average year, unless you've got a caper bush.

"They do it every year, but this year's been particularly good for butterflies across the board, because it's been so wet in Central Australia and their numbers have really built up, so there's just a gazillion of them."

However, while they might live for weeks, or even months, the butterflies that arrive in Adelaide are not the same ones that depart the middle of the country when the migration begins.

"The same butterfly that leaves Alice Springs is not the same butterfly that arrives in Adelaide," Ms Messenger said.

"It might be generation five or four that arrives here."

Gardens are safe

Keen Adelaide gardeners do not have to worry about the caper white caterpillars eating their vegetable patches.

The butterflies drink nectar, and the caterpillars only feast on caper bushes.

Kate Grigg purposefully grows many plants that attract lots of insects and wildlife, including a large caper bush in her front garden.

She said the bush saw the arrival of the migrating caper white butterflies about two weeks' earlier than anywhere else in Adelaide.

When she notices the butterflies, she provides that intel to Ms Messenger as a "butterfly spotter".

The conservationist and horticulturist is not sure why the caper white butterflies love her garden so much.

"But I think we're pretty lucky here and we get them in plague proportions,"

Ms Grigg said.

"It's all about promoting biodiversity really, but also things that make me happy."

Ms Grigg has also noticed the higher than usual numbers of caper butterflies this year.

"It seems to be the first year that we're getting the males and the females, so they're mating on the bush which is something that I haven't actually noticed previously," she said.

She wanted to encourage people to plant caper bushes in their yard to attract the butterflies.

"It's pretty much that simple," she said.

"They (the caper white butterflies) will track 'em down, and they are such a hardy plant you really don't need much experience to look after them."

Butterflies and other insects

Large numbers of dragonflies and other insects were also expected, according to Ms Messenger.

"It's fair to say it's the year of the bug this year, the insects and the invertebrates are having a very good time,"

she said.

"I've seen lots of dragonflies completing their life cycles, there's lots of food for them to eat.

"We're probably seeing a lot more grasshoppers, because there's a lot of pasture food for them."

Ms Messenger said there were several other butterflies that people should also be on the lookout for, including chequered swallowtails that host on native scurf pea, red spotted jezebel butterflies that are attracted to quandong and the yellow admiral butterfly and lesser wanderer butterfly.

"(The lesser wanderer) is a little bit like a slighter smaller monarch mimic," she said.

"Monarch (butterflies) are an invasive species, so they are around at the moment as well. 

"But the lesser wanderer is the native version of a monarch, and they're around in pretty big numbers at the moment too."