I initially thought it was just a big stupid ant who dared to wander around the spider's nest. Was it not afraid of being eaten by spiders? I didn't expect it to sense my camera lens close to it, and it turned around and stared at me with big dark eyes with sunglasses. I suddenly realized...Aha! You are not an ant, you are a spider that looks like an ant. Your name is "Antmimicking spider".
Generally speaking, the body color of the Antmimicking spider is dark. But the Myrmarachne formosicola has a more variable body color, ranging from reddish brown to brown. Its head is black, with a white triangular spot on the lower edge, and a wide black horizontal band instead of a constriction on its abdomen. In contrast, the Myrmarachne formosana has a obvious narrow in the front third of its abdomen, that looks like a bottle gourd.
一般而言，蟻蛛的體色黑溜溜的一片。然而，擬台灣蟻蛛(Myrmarachne formosicola)體色較為多變，大致呈紅褐色至褐色。牠的頭部黑色，下側緣有一枚白色三角斑，腹部不具縮隘，而是有一條寬型的黑色橫帶。相較之下，台灣蟻蛛(Myrmarachne formosana)腹部前三分之一處明顯收窄，呈葫蘆狀)
The male spider has a pair of well-developed big jaws (chelicerae). The jaws I observed was only a usual size, and it should be a female spider. Myrmarachne formosicola are generally distributed on flat to mid-altitude mountainous areas. They look like ants, but they are much larger than most small ants on my balcony. Internet data say they are 6.8mm long.
to be continued... (未完待續...)
Note 1: Ants do not rely on their eyes to perceive their surroundings, so they will not respond to people's approaching actions at a certain distance. They are always busy working. But the central pair of eyes among the eight simple eyes of antmimicking spiders are like a pair of sunglasses. They are so big and they can see if people get close to them. So they may hide or run away; they may also turn around and stare at people with sunglasses.
Note 2: There is a class of members of the Salticidae (Jumping spider) family, which resemble ants in appearance and are classified into the genus Myrmarachne sp.. They are called antmimicking spiders. Why simulate ants? Perhaps because ants have fewer natural enemies. So jumping spiders imitate insects such as ants that are not popular with predators and will reduce the chance of being preyed. Many creatures that hunt by sight do not like to attack ants or regard ants as unpalatable food.
Antmimicking spiders move mostly by walking, but if they want to move from one leaf to another, they often do it by jumping (because they are members of the Jumping spiders). This is weird, how can an ant jump? As a result, we will find that this is antmimicking spider instead of an ant.
參考資料: 模仿螞蟻的蜘蛛 楊家旺 (2009.05.24)