The skies are aflutter in south-east Queensland with unusually large numbers of butterflies, experts say.

The combination of rain and heat has provided perfect breeding conditions for the insects.

Queensland Museum's director of entomology, Dr Christine Lambkin, said she had received reports of the biggest numbers in 40 years for some species.

"We have seen large numbers of butterflies in south-east Queensland, and northern New South Wales, mainly because we've got both migrations but we have also got emergence," she said.

"So we have got large numbers of all sorts of insects but particularly noticeable are the butterflies.

"I am seeing numbers of one a second ... but I am not sure how long that kept up for. But yes, definitely very large numbers of certain species at the moment," Dr Lambkin said.

Dr Lambkin said the rain, along with the heat, had produced the bumper numbers, with caterpillars gorging on plant growth before transforming into butterflies.

"We have had a long extended dry period that has been broken by good rains at the right time of the year," she said.

"So we have got the warmth as well as the rain and that is what has caused the adults to break the aestivation, which is the insect hibernation, and emerge in numbers.

"Some of them will be trying to mate and lay eggs so that the caterpillars are going to come up on that flush new growth from the rain," Dr Lambkin said.

Brisbane resident Ross Kendall breeds butterflies for weddings and funerals and is president of the Butterfly and Other Invertebrates Club.

He said it had been up to 15 years since he had seen such a big migration of the butterfly known as the blue tiger.

"They are literally flying in their millions and this is because of our good wet season," Mr Kendall said.

"The plants that they breed on have shot up vigorously and females have busily laid lots of eggs, and the caterpillars have survived and gone through to butterflies."

A small white, gold and black butterfly known as the caper gull had also been seen in bigger numbers.

"You often see small numbers of them but this year they are around in their tens of thousands as well," Mr Kendall said.

Mr Kendall said it was good to see the ecosystem thriving courtesy of the rain.

"To know that we have had good rain and a good season and insects are dependent on vegetation and vegetation is dependent on the rainfall and when we have got good rain, there is an explosion in all sorts of insect populations," he said.

"And it is great for the things that then eat insects."

Butterflies not the only insects booming in Brisbane

While it is a treat to see the Blue Tiger, the wet conditions are also prime for locusts. ( Supplied: Hongming Kan )

While soccer fans have descended on Lang Park for the Asian Cup, moths have also been drawn to the action, swarming around players during last weekend's match between the Socceroos and South Korea.

At a press conference, Socceroos forward Tim Cahill was asked whether the moths had been a distraction during the team's 1-0 loss to South Korea.

"Moths and football pitches, they are definitely an element, but when you are playing a football game, we are professionals," Cahill said.

The wet conditions are also right for locusts, which can damage crops and eat pastures, reducing grass for livestock.

The Australian Plague Locust Commission is monitoring numbers of the insects in parts of central and south-west Queensland, around Injune, Rolleston, Roma, St George and Condamine.

The Commission's Chris Adriaansen said there might be isolated areas of high density locusts from late February to early April, but there would not be a widespread infestation of states like the plague of 2009-10.

"Certainly there will be problem numbers for locusts as we often see in seasons such as this," he said.

"Individual landholders will need to look at whether it is worth their effort and money to undertake control on their own properties.

"We will see some areas where higher density patches may affect pastures and crops but we will have to wait and see what the third generation [of locusts] does to see if we have enough of an infestation to warrant a widespread control program."