University of Kentucky Entomology for Kids: Bolas Spiders

If this were not from an Entomology Department website I might have dismissed it as a probable hoax:

Bolas spiders are relatively rare members of the large family known as orb weavers. Instead of using a typical web to capture prey, nearly mature and mature female bolas spiders swing a droplet of adhesive on a thread at flying insects.

Mastophora hutchinsoni is one of five Mastophora species known from the United States and occurs over much of North America. It has only one generation per year in Kentucky and overwinters in the egg stage. Spiderlings emerge in May. Males, which are much smaller than females, mature in late June and early July; and females mature in early September. Eggs are produced from late September to late October or early November. Newly emerged spiderlings do not use a bolas, but instead hunt by placing themselves on the underside of leaf margins where they ambush small prey that crawl along the leaf margin. Mature and nearly mature female M. hutchinsoni use a bolas to capture moths.

Only male moths were captured, specifically three species of Noctuidae (bristly cutworm, bronzed cutworm and smoky tetanolita) and one species of Pyralidae (bluegrass sod webworm). Among 492 prey captured by more than 20 spiders at two sites during 1985 and 1986, smoky tetanolita moth and bristly cutworm moths accounted for 93% of the total. The flight behavior of approaching moths, the limited kinds of moths caught from a large population of other kinds of available moths, and the fact that only males were caught support the hypothesis that the spider attracts its prey by producing chemicals that mimic the sex pheromone of these moth species. A spider often captured more than one moth species on a given night.

Roundabout hat tip to this Bogus Gold post, which got me to the University of Kentucky Entomology Department website, on which I am having oodles of fun...

But, to continue...bolas spiders? I didn't know about these creatures. (Pause while blogger googles a bit...)

Hey, here we go. Australia has bolas spiders, too, and here's one they call the Magnificent Spider. From the picture, I'd have to say the looks are more strange than magnificent, but to each his own, I guess.

From the Australian Museum Online fact sheet on bolas spiders:

The Bolas spider group has evolved a highly sophisticated way of capturing prey. These spiders use a single line of sticky silk to capture moths, which are lured by pheromones released by the spiders. There are several species worldwide, with three species found in eastern Australia: Ordgarius magnificus, O. furcatus, and O. monstrosus....

Monstrosus? That I'd like to see... ( And while this picture might serve for a poster for a boy's room, I don't think I could identify any spider from it... )

During the day, the Magnificent Spider hides in a retreat made by binding leaves together with silk. Preferred trees include natives such as eucalypts in dry or wet sclerophyll forests, but these spiders are also found in suburban gardens. Often the spider's characteristic spindle-shaped egg sacs are hanging near the retreat. Ordgarius magnificus is found in Queensland and New South Wales...

A medium sized spider (1.4 - 2.5 cm), the female Magnificent Spider is very distinctive in its markings. It is white with two bright yellow knobs on its abdomen, and a number of salmon-coloured spots and blotches as well. The body and limbs are covered with long fine hairs, especially the forelegs. The male is tiny (1.5 mm).

What's that saying about truth being stranger than fiction?

A question. In Kentucky bolas spiders are in the genus Mastophora, and in Australia they are in Ordgarius? (Just to make it even more fun, on the Magnificent Spider fact page it says that Ordgarius magnificus used to be known as Dicrostichus magnificus.) How many genera of bolas are there anyway?

P.S. I have a sense of humor. If you make up something like Neckwearichus I won't throw things at you. I might groan, but I won't throw things at you - as long as you make it clear that you are being funny and not relaying actual scientific information. Note: I've just checked my UK dictionary, and it doesn't have bola ties listed. Nor bolo ties - the same thing, just spelled differently. Hmmm. You can't get the joke if you don't know about bola ties... See here for examples, and here for history and commentary. Some people just call them western ties, if that helps any, but around here we call them bolos or bolas.

P.P.S. If you don't know about the original bola, the weapon for which the spiders are named, see these pictures for examples.