Buggin with Bridgey – May 2023

Buggin with Bridgey is a Monthly report of sightings from the Let’s Go Buggin Cairns Nature Tour in the Cairns Botanic Gardens.  As the months roll by, subtle changes in the seasons bring sightings of new creatures and this report aims to give people a wrap up of the current animals seen as well as provide an ongoing citizen science account of our wonderful critters that can be seen in the tropical north of Queensland.

BIG in Cairns Botanic Gardens – Arthropod Edition!

Following on from the April blog ‘Big in Sumatra’ I thought I would continue the theme and talk about the big ‘little’ things that can be found in the Cairns Botanic Gardens.    Of course, arthropods could be considered small things when you comparing it to a human or a snake but there are several types of spiders for example that we do consider big ‘spiders’ so I will be focusing on species that are big within their own group of animals.

Longicorn Beetle (Rosenbergia megalocephala)

Unfortunately I’ve only seen fantastic beetle once, but wow did it leave an impression!    It appears that it isn’t a very common species as according to iNaturalist there are only a few observations mostly in Far North QLD an one in Darwin. I feel very privileged that I was able to meet this big beetle. Its body is about five centimetres long, a lovely cream colour with black spots and orange on the sides. Its antenna spanned 15 centimetres.  Now that’s one big beetle!

A big longhorn beetle sitting on a green fern. It has long antennae and is creme coloured with an orange stripe and black spots.

Longicorn Beetle (Rosenbergia megalocephala)

Giant Golden Orbweaver (Nephila pilipes)

Impressive, formidable, scary, gorgeous…all these words have been used to describe this huge orbweaver that is a common site during Let’s Go Buggin morning and Night tours. Fully grown females can reach as large as a large male human hand. Their webs can be one and a half metres wide. Their webs are certainly not one you want to walk through…but this is only a instinctual fear…as these spiders are not medically significant and rarely bite.  Their name comes from the gold silk that can be seen on the Web. The silk is so strong that it can capture small bats and birds which will feed the spider for a month or so.

A big long legged spider with orange and red legs sitting on a web with a Cicada caught in the web

Giant Golden Orbweaver (Nephila pilipes) with cicada in caught in the web

Cairns Birdwing (Ornithoptera euphorion)

Australia’s largest endemic butterfly lives in Cairns and lucky for us it is quite common.  It’s a regular sight to see them gliding around the Cairns Botanic Gardens and the Wet Tropics of Queensland.  It’s the adult females of this species that are the huge bird-like black beauties gracing us with their presence.  Their wingspan can reach an impressive 15 cm (5.9 in) in females, and 12.5 cm (4.9 in) in males.  We can see them at any time of year but most of the sightings are during the wet season.  You can often find courting pairs flying around together. The male will keep guard of his female after he meets with her to ensure that she will not meet with any other males.  Of course, a big butterfly needs a big caterpillar and these glorious black spiky caterpillars will wow anybody that sees them.

A freshly emerged Cairns Birdwing Butterfly sitting under a leaf while its wings dry. You can see the cocoon in the photo. Australia's Big butterfly in the Cairns Botanic Gardens.

Freshly emerged male Cairns Birdwing Butterfly (Ornithoptera euphorion)

A sleeping big Cairns Birdwing Caterpillar in the Cairns Botanic Gardens

Cairns Birdwing caterpillar (Ornithoptera euphorion)

Grey Huntsman Spider (Holconia immanis)

I’ve had a soft spot for this species ever since I came across a resident who I named ‘Henrietta’.  She was living on a Raintree in the Cairns Botanic Gardens.  We would see this big beauty regularly on our night walks. We watched her over nine months hunting on her tree.  When we first met her she was perfect, huge and beautiful, and impressed all that saw her.  Around two months later she was missing her two front legs. She disappeared for a month or two and then returned with fresh new legs.  We later saw another individual on the tree.  We continued to see Henrietta for another few months and then she seemed to vanish. We have since seen what I can only assume were the next generation not once but two years running. We are currently enjoying seeing Henrietta III on the same tree on a weekly basis. The species is considered Australia’s third largest huntsman spider, reaching 16 cm across and can be found throughout the eastern coast of the Australia.

A big Grey Huntsman Spider sitting on a moss covered rock

Grey Huntsman Spider (Holconia immanis)

Giant Rainforest Mantis (Hierodula majuscula)

Anyone who has been following me knows my love of mantises. We do have one of the biggest hanging out in our gardens of Cairns.  The species is usually very cooperative in front of the camera. You can get a variety of poses from them and they often look directly at the camera lens which makes this species an absolute delight to photograph. They can be found on the coast of Queensland in rainforests and also fringing grasslands and residential areas.  Most individuals are green but there is a colour morph of a rich purple-brown colour and also a bright yellow.

Giant Rainforest Mantis (Hierodula majuscula)

Spiny Rainforest Katydid (Phricta spinosa)

One of the most impressive beasties you can come across in the rainforest of the wet Tropics of Queensland is this big Katydid.  It’s an endemic species, so for those of you who are into big arthropods, this should be on your wish-list on your next visit to Cairns.  When they are young they have a flamboyant camo design on their body that is incredibly ornate. Once they get to around six centimetres and emerge into their adult phase, they lose this coloration and turn a creamy-brown. Antennas can reach 20 cm so full length of the species can reach around about 30 cm.

A green spiny grasshopper-like insect sitting on a leaf. A Spiny Katydid is a big insect found in the Cairns Botanic Gardens.

A young Spiny Rainforest Katydid (Phricta spinosa)

Spiny Katydid closeup. A green spiny grasshopper-like insect sitting on a leaf.

I hope you enjoyed seeing some of the BIG arthropods in the Cairns Botanic Gardens. If you would like to take a deeper dive into some other encounters you can check out my Let’s Go Buggin Project on iNaturalist here.

Keen for a Let’s Go Buggin Tour? Use ‘blog’ as the coupon code for 15% discount on your tour booking here.

Next Blog in late June.

🐞 💚 🕷


Bridgette uses a variety of Olympus OM SYSTEM Cameras and Lenses