Spider identified and mantispid emerges

We have identified  the crab spider as Poecilothomisus speciosus (thanks Colin). It is the sole member of the genus in Australia, and is only found in north eastern Queensland. We are not sure why the Australian spider has been placed in a genus by itself, whilst the related overseas species are all members of Platythomisus - had me confused.

Today the eggs hatched but only a handful of tiny spiderlings emerged from the egg sac. The reason for this was because an invader had also been occupying the egg sac - a mantispid.  Mantispids are mantis-like Neuropterans and some species select spider eggs as food while they are in larval form. Mantispids use two strategies to access spider eggs; some larvae find an egg sac and burrow in through the silk, while other species hitch-hike upon the female spider and enter the egg sac as it is being constructed. We are not sure which strategy this particular species used, but it was successful.

The mantispid shortly after emerging from the egg sac.

Mystery spider

For the second time in recent years I have swung my torch around to reveal a brightly coloured spider sitting in a tree and knew that I was looking at something very unusual.

In 2006 it was the Tiger Huntsman which turned out to be the first recorded specimen of an undescribed species in the genus Typostola - it is still awaiting description. The fact that you can still find species that are new to science is one of the very exciting aspects of the wet tropics.

This time however, the spider may not be one that is undescribed, but one that is not well documented in Australia. Its movement and body form are clearly that of a crab spider; family Thomisidae. After some sleuth work I have managed to tentatively identify it as Platythomisus sp.. Around 20 species are recorded from Africa, through southern Asia, but apparently not in Australia.

The obvious question beckons: Is this an Australian species or is it an introduced specimen? The plot thickens further as I found this specimen peeking out of a curled leaf whilst incubating eggs.

I will endeavour to contact an arachnologist who has experience with Australian Thomisids to answer this one. Stay tuned!

The specimen is quite large compared with the majority of Australian Thomisids. Body length 14mm.

The markings on this specimen are quite stunning and are very similar to Platythomisus spp. found throughout Asia. It does have distinct differences though.

For a small spider it is quite aggressive and actually tried to bite my finger whilst I was taking these photographs.

One of the first things that struck me was the superficial resemblance to the spitting spiders Scytodes. Interestingly, one species of Platythomisus has been named P.scytodimorphus

Daylight robbery

This stunning fly is one of several species of Robber flies (Family Asilidae) that are active at the moment around our home. Robber flies are active hunters that catch prey in flight, or pluck it from foliage. They have huge eyes, excellent vision and a capacity to turn their heads rapidly to keep track of prey or threats. They feed through a large proboscis which is driven into their prey to extract its body fluids. Some species are nocturnal and we have observed them feeding on large cockroaches, but the species below is active by day. Robber flies will often fly short distances and return to the same area to wait and watch for potential prey, making them reasonably easy to observe and photograph.

This Robber fly is feeding upon a blowfly

Sun lover

Cockroaches aren't usually associated with sunbaking, however cockroaches in the genus Elipsidion are renowned for basking in the sun during the day. They are spectacular cockroaches with vivid markings, some even have transparent window-like areas in the pronotum. I photographed this specimen soaking up the rays in the dryer country west of Kuranda. It is a young specimen (a nymph), and will have fully functional wings once it matures. These cockroaches inhabit the foliage of various plant species, and most likely feed upon pollen, honeydew and fungi.

Our porch visitor

To our delight, a Yellow-bellied Sunbird, Nectarina jugularis, has made its suspended nest right next to our rear patio door. This species is a small nectar feeding bird, only 10-12cm in size. We were able to watch the bird produce its nest from the very early stages; the bird returning every minute or so with more building material. Once the pendulous nest was completed, the soon to be mother settled in and we have only seen glimpses of her through the nest’s small circular opening.

Yellow-bellied Sunbirds lay 1-2 eggs with an incubation period of 14 days. Young fledge 15 days after hatching although the survival rate for nestlings is only around 20%. Two nights after the nest was built we were awoken by a terrible shrieking sound coming from the nest. We suspected a Brown Tree Snake, Boiga irregularis, was attacking the bird, but upon inspection no such predator was present. The Sunbird has since been seen in her nest so everything appears normal again. We can only wait and see what happens and wish her luck.

The Yellow-bellied Sunbird halfway through nest construction

Experts in camouflage

One of the largest and most common katydids in northern Queensland is also one of the most seldom seen. The Spiny Tree Katydid (Phricta spinosa) has excellent camouflage and positions itself motionless on tree trunks through the day to avoid detection by visual predators. The specimen pictured below was beside a rainforest walking track, where I witnessed tourist after tourist wander by within 40cm of the katydid looking for nature, but obviously not looking hard enough...

The Spiny Tree Katydid resting on a small tree adjacent to the walking track.

A close-up of the head of the katydid. The spines, colour and pattern all help to break up the outline of the animal resulting in excellent camouflage.

Eight legs beats thirty

On a recent field trip to collect house centipedes (Scutigeridae) for the filming project we are working on, I found a large specimen but not quite in the way I expected. This one had just been caught by a Brown Huntsman (Heteropoda sp.) and probably wasn't going to be much use to us on set! These centipedes have 15 pairs of long thin legs, and needless to say they move very fast. As quick as huntsman are, it is still surprising that it managed to catch such a sensitive and rapid moving animal.

House centipedes have two large compound eyes contrasting with other groups of centipedes which have smaller simple eyes. They are predatory and venomous, injecting their venom through short modified legs which act as fangs. These 'venom claws' are located just below the mouths of house centipedes.

The name 'house centipede' originated overseas due to some species occurring inside houses. Ironically most species of house centipedes never come inside.

The Brown Huntsman (Heteropoda sp.) feeding on the house centipede.

A specimen we found a couple of nights later at the same site. This species can attain a body length of almost 60mm with a leg span of over 100mm.