Dewdrop Spider - Argyrodes antipodianus

Click image to enlarge

Dewdrop Spider - Argyrodes antipodianus

The Dewdrop Spider is also known as the Quicksilver Spider because of their bright silver abdomen, however these are minute spiders, being no larger than a match head (2-3 mm or less than 1/8" in body length) and so are not noticed unless sought. Small size can nevertheless still be an advantage in making a living, for these are kleptoparasitic, which means parasitism by theft and they live permanently as a parasite in the webs of large orb-weaving spiders and particularly the widespread Golden Orb-weaver, Nephila edulis ( Spiders - Modern - Golden Orb ), but they will also occupy other spiders webs. What the Dewdrop Spider seek are large permeant webs made by large docile spiders.

These small spiders actually do the large spiders (whose web they cohabit) a favour by keeping the web clean of tiny flying insects that are much too small for the larger spider to be bothered with, however the dewdrops are not too timid to take a share of the larger spiders meal and will even partake at the same time. The dewdrop spider is quite communal and webs can be occupied by several individuals, but being so small, having others on relatively vast webs that can stretch for 2-3 metres, any disruptive interaction over territory is probably unlikely.

One of the photos above show a juvenile Golden Orb Spider with a dewdrop spider off to the left. It is interesting to note the similar silver reflective color of the larger spider, and as many of the large orb spider hosts reflect light in this manner, I wonder if the silver coloration may have an influence regarding the small dewdrop spiders acceptance within the web.

Comb-footed Spiders - Theridiidae species

Click image to enlarge

A small species with the larger females being around 6 mm (1/4") in body length, they can often be found in considerable numbers around the outside of window frames (they are rarely seen inside). Its fangs are probably to small to penetrate human skin, but like most spiders, the potency of their venom is unknown and they should be treated with respect and not handled.

Comb-footed Spiders - Theridiidae sp.

These Comb-footed Spiders are in the same family as the highly venomous Red-back and Black Widow Spiders, however these other family members are only known for giving the odd painful bite and are not generally considered dangerous, but coming from such a notorious family it would be wise to treat all with caution and not handle them. In the Australian section of the Theridiidae family, there are around 100 species divided into 16 genera, so apart from the Red-back, many tend to look very similar and are not easy to positively identify. They are called comb-footed spiders because of the forward facing serrated hairs on their hind legs, which are used to comb out wide sheets of silk when wrapping captured prey.

In the photographs there are at least 2 or maybe three species. Those with the darker marking on their back are slightly different to the others, although their shape is very similar. To identify similar looking spiders it is important to note their web/retreat and preferred habitat. With the spider in the top three photos, they prefer to make a small untidy web/retreat in the corners of windows, preferably with a light shining through at night to attract small flying insects. The other two photos are spiders that prefer a more lofty open space close to a roof, constructing a more typical Theridiid web of long sticky threads attached to an upper tangled one in a darker location.

The above examples show a preferred habitat and probable prey difference, but there is a more obvious differing characteristic, that being the egg-sac. One has a parchment like sac, whilst the other a soft finely woven one indicating clearly they are separate species. Therefore if you are wandering around and see very similar looking spiders, don't rely on initial observations, have a closer look and you may find you have more than you first thought.

These two Comb-footed Spiders are a little larger than the above species, being around 10 mm (3/8") in body length and are also outdoor types, rarely if ever entering houses. It is possible they are the same species, as these heavily mottled varieties often come in lighter and darker combinations, but I would not place any money on it. Theridiidae species of this size probably can penetrate human skin, so definitely a no, no, regarding handling.

Red-back Spider - Latrodectus hasselti

Click images to enlage

Red-back Spider - Latrodectus hasselti

A very common spider in the Esperance region and most of Australia. Closely related to the American Black Widow Spider and like it, the Australian Red-back also has a deadly bite and is particularly dangerous to young children and the sick. There have been a number of deaths attributed to the female of this spider (the male is too small to penetrate human skin), but this was before an antivenom was developed (over 40 years ago) and since then there have been none. Fortunately, they are not an aggressive spider and usually only bite when picked up, or if firm direct (mostly accidental) contact is made with them.

Their tangled-web is usually made well within 1/2 metre from the ground (1' 6"), with the main part under a overhang that will provide dry shady conditions. It is an untidy web with the upper part being very tangled and entwined with many silken threads extending to the ground where fixed and several sticky droplets attached. When something small wanders into one it becomes stuck to the droplets and the thread will break off at the base. The thread is in tension so when this happens, the captive is lifted into the air where it can be dealt with once it tires. These threads are very strong and I have seen geckos and small skinks caught in them unable to escape. Frogs and large spiders including trapdoor and wolf spiders are also caught and eaten.

The female Red-back Spider is mostly a glossy black with a scarlet stripe down the back and a similar colored hour-glass marking under her abdomen. The markings on some spiders are a bright orange and some have no markings at all, but I have not seen the latter in this area. They vary a little in size from 10 mm to 15 mm (1/2") most of which is a bloated round abdomen.

The male red-back spider is tiny in comparison to the female and usually less than 5 mm. (around 1/8") and although there are often more than one in the females web (they don't build one themselves) and are seldom noticed. They too usually have similar red marking on their body, but not as pronounced.

Red-backs are quite social and often have their extended family staying in the large female's web. Sometime a mature female will also be present, but she is always smaller. The juvenile female has very attractive stripes down the sides of her abdomen that will be lost when she matures.

Juvenile males are quite weird with little coloration and appear to be something from another world.

A juvenile female Red-backed Spider with a mature male.