Buggin with Bridgey – September 2021

Buggin with Bridgey is a Monthly report of sightings from the Let’s Go Buggin Photography 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.

Nature & Photography Tour Cairns Botanic Gardens – Let’s Go Buggin SEPTEMBER Monthly Report

‘Feelin Crabby?’

Crab Spiders (Thomisidae)

Crab spiders are a family of arachnids that have similar anatomical features, especially in the eye configuration. There are a number of species that are common in the Cairns Botanic Gardens and I regularly find them on Let’s Go Buggin Tours as well as in my backyard and other gardens all over the area.  They are in great numbers right now, which seems to be aligned with the start of the spring season.

Crab spiders get their name from their crab-like appearance.  They will hold their two sets of front legs in a very similar position to a crab and are often witnessed walking sidewards and backwards!   Their eyes are quite small compared to a lot of other spiders.  Especially Jumping spiders whose eyes can be 20 times larger!

Crab spiders don’t build webs, instead will hunt as ambush predators.  In fact their bodies are known to reflect UV light and in doing so will attract bees towards them, much like flowers attracting bees.  Once an insect or spider comes within striking distance it is almost certainly a victim of these skilled hunters.  I’ve seen them take down prey five times their own size, including large caterpillars, larger spiders and butterflies.

All Photographed in the Wet Tropics.  1. Spectacular Crab Spider (Thomisus spectabilis) showing yellow colour morph 2. Leek-green Flower Spider (Lehtinelagia prasina)  3. Unknown Thomisid  4. Stephanopis sp.  5. Cymbacha sp.  6.  Bird-dropping spider (Phrynarachne decipiens)

Beautiful Crab Spider (Poecilothomisus speciosus)

The Beautiful Crab Spider is thought to be fairly common in the wet tropics, however rarely seen.  I can say I’ve only seen seven of these amazing spiders, which is a shame, because a real-life spotting of these spiders is an alarming experience with their bright white and yellow colouration being a major contrast to its environment.  They are quite simply stunning little spiders.

I once was lucky enough to have one in my backyard. She had sewn together some palm leaves and each time I went to look at her she came raging out with her arms in a very defensive dance towards me. I could see she had a nest she was protecting.

I have since seen another five or so of these spiders in the Cairns Botanic Gardens and other locations around Cairns and Babinda.

1. My first sighting of a Beautiful Crab Spider at Babinda Boulders.  2.  A defensive mother protecting her egg sack (top right corner) in my backyard in Cairns.

A few days later, I spotted Sara eyeing off a Green Grid Stink Bug (Antestiopsis cederwaldi) that I’ve been seeing so many of lately.  I quickly grabbed my camera and came out and she had decided to go for the beetle.  I watched her with the beetle for a minute or two while I took these photos…and then she decided to release the beetle.

As to why she did this is a mystery, any crab spider expert witnessed this behaviour before?  The beetle was fine, it moved around the flower and eventually settled just inside the cluster of flowers where Sara was sitting on the other side.   It seemed as though they are just going to tolerate each other?   How can this be?  Checked a bit later and the beetle had moved on.   Did the beetle not taste good?  Was it immune to its venom??  A quick Google of this species will show there is not much known about this bug.  Any Bug experts out there?

Well if you made it this far in my Blog you must be at least semi-interesting in the world in our gardens.  I’d love to show you more on a Let’s Go Buggin Tour!