During a few select months of the year in the arid heart of Australia, butterfly populations explode and take on an important role in the desert’s ecology.
- Butterflies play a vital role in the pollination of flora in arid desert zones
- Their numbers increase in the months when it’s not too hot nor too cold
- In spring, the butterflies are different to the ones you would see earlier in the year
Kym Schwartzkopff, a senior wildlife ranger with Northern Territory Parks and Wildlife, said when the air temperature was not too hot nor too cold, a kaleidoscope of butterflies spread their wings over the dusty red landscape.
“Generally, butterflies start at the end of March and go through until April,” he said.
“During July we’re right into the colder months, so there won’t be anything at all as it will be too cold for anything to move.
“Once it starts warming up again, you’ll get another influx of butterflies back out around September and October.”
Butterfly numbers depended on rain and accessibility to food, Mr Schwartzkopff said.
“We’ve had good rains in the last couple of months, and we’ve got a lot of flowering plants and a lot of grasses that are coming up at the moment that the larvae are feeding on, so they’re making the most of it.
“The food source the butterflies rely on are more the flowering plants.”
The insects have a longer life cycle than moths, which generally only live for several days, although they appear four weeks ahead of the butterfly season.
“Most butterflies would probably last up to about two weeks at the most,” Mr Schwartzkopff said.
And that fortnight is crucial for the survival of native flora, he added
“So without the butterflies, you’ll mostly find in Central Australia that there would be a lot less flowering plants around the place.”
Fascinating to watch and study
Several varieties that come out in autumn include the pea blue and the caper white, which is a migratory butterfly.
“So they follow their food source around and they feed mainly on a type of caper vines, which are passionfruit, wild orange, those sort of things,” Mr Schwartzkopff said.
The little pea blue is common for the region and, interestingly, help ants survive in the hard climatic conditions.
“You see those more around mulga or flying fairly close to the ground. They predominately feed on the the mistletoe plants around the area.
“Their larvae pupate inside ant holes. The ants gather up the eggs that the little butterfly produces and take them down into the holes.”
The caterpillars live off the ant larvae, but in return, Mr Schwartzkopff said, they give the ants “a little sack of honey or sweet nectar which the ants love, so they look after the caterpillars until they’re coming out and pupate.”
In spring, the butterflies are different to the ones you would see earlier in the year.
“You’ll get more of the glass wings, the common egg flies, which is a large butterfly and they’re quite dark.”
Mr Schwartzkopff said given social isolation restrictions, more people should take notice of the influx of butterflies.
“Most people do see butterflies around, but most really don’t take much interest in them,” he said.
“They’re always there, but once you start taking a bit of a look and getting to see what’s what, they’re a really fascinating little insect to watch and study.”
It’s all about sex
Even though butterflies play an important role in the pollination of native species, they are not born pollinators given their short lifespan, according to bee trainer Vicki Simlesa.
“Eighty per cent of their food source comes from bees, not butterflies, given their lifespan at six weeks is much greater than the butterfly,” she said.
“In the two-week lifespan of butterflies, they are more interested in sex, whereas bees are colony-driven to support their queen and the existence of the colony as a whole.”
Ms Simlesa said the female worker bees headed out of the colony without any sexual appetite.