Oval St. Andrew's Cross Spiders (male and female)

Description:

There are six Species of Argiope Spiders in the Philippines, but only three of them are present in the area where I live. They are A. catenulata, A. luzona and A. aemula. My favourite is Argiope luzona because it is, by far, the most numerous in our area and creates the widest range of web decorations. However, Argiope aemula, the spider shown in this spotting is very beautiful and I don't see it very often. So, I was extremely happy to see both male and female today. Pic #1. A dorsal view of the female, sitting on the hub of her web. She is a fully grown adult (approx. 25 mm. body length), Pic #2. A rather poor ventral view (too much spider silk getting in the way). Pic #3. The male spider, sitting on the stem of a dead Tropical Whiteweed, right at the edge of the spiral capture zone of the female's web. He is very small (only around 6 mm, body length). He appears to have all four legs on his left side, but on his right side, he has completely lost legs No.1 and 2. only small stumps remain of legs No.3 and 4. More about that in Notes. My pictures of the male and female are not to scale, but it is easy to see that the male is so small that he could easily fall through the mesh gap in the female's capture zone spiral. Pic #4. A view of the female, showing a wrecked Three-arm Discontinuous Cruciate Stabilimentum (A. aemula never makes a Continuous Cruciate Stabilimentum). The cause of the damage is almost certainly an accidental "walk through" by a neighbour's water buffalo. Grass is in short supply, in the dry season. So, we allow neighbours to graze their animals on our land when their own grasses run out.

Habitat:

Spotted in the farm on Tropical Whiteweed (Ageratum conyzoides Linn.) known in the Philippines by various names in many dialects. In our local dialect, this plant is called Salunay. Plant information - http://stuartxchange.com/Bulak.html

Notes:

Spiders, in general, live brutal lives and Argiope spiders are no exception. They live by capturing, killing and eating insects and they, in turn, are often captured and killed by other predators, noteably Mantises (which lurk near the perimeter of the spider's web and grab the spider if it comes within reach. A mantis is too smart to step onto the web) and Spider Wasps (which zoom in at high speed and snatch an inattentive spider from its hub). So, the spider must not spend too much time near the edge of its web, if a prey insect lands there and when it is sitting at the hub, it must be attentive so that it might spot a spider wasp and escape by "shuttling" to the other side of the hub. However, none of this is in play here. The tiny male must mate with the female to pass on his genes to the next generation. He has to wait, for days, watching for a sign that the female will accept him then he must copulate, and try to escape. An attempted escape is rarely successful. The female launches a savage attack, after mating, and nearly always kills the male and eats him. If the male is super-fast, he might escape, but will often be injured severely, like the male in my photos. Perhaps the strangest part of this murderous mating is that a male which survives the first mating, will rest for a while and then go and mate again (if the female allows it), but there is no surviving the second time. When the mating is finished, the female, once again, attacks the male which no longer even tries to fight for survival. It, knowingly goes to its death on the second mating. I am not sure about this, but it might just be that the male understands that if, by some amazing chance, he kills the female.... there would not be a next generation and it would all be pointless.