Araneae (spiders), continued

On this page, Spider courtship mating and behaviour, how spiders eat, Ballooning, Spiders and gardens, Amazing spider snippets, Featured family list , a whole lot more

Spiders and gardens

Amazing spider snippets

Spider courtship, mating and behaviour

Courtship of the female by the male can be elaborate, but much of this is to make sure that the female can distinguish him from a juicy meal! In the web building families the male will abandon his web on reaching maturity to go in search of females. In the U. K. this happens to males in the Agelenidae family at the end of summer, which is why as the weather cools you will find huge males with swollen palps running across you floor, in your bath, almost anywhere they think there may be a receptive female sitting in a web.

Before mating the male spider deposits a drop of sperm from ducts emptying into his epigastric furrow on the surface of a small sheet of silk, and then transfers this to his palps which swell up to look look boxing gloves (see the photograph below) as they pick it up the sperm by capillary action. The male's palps fit into the female's epigyne like a key fits into a lock. This prohibits mating with the wrong species. Once a male has loaded his palps with sperm he is ready to go off courting.

In species which spin webs (who tend to have bad eyesight) their courtship is based on chemical signaling and vibrations. The male will pluck, tap and vibrate the strands of the web to attract the female's attention. All spiders are very sensitive to vibrations. He may hang around the web for days before making his move.

Some species wait until the female is occupied with prey, e. g. Metellina; others until she is about to moult. Some supply a prey item wrapped in silk as a gift. While she is unwrapping the present the male will mate with her. In species with good eyesight such as the Lycosidae and Salticidae, the males signals his intentions with his legs and palps.

Tegenaria duellica mature male showing palps, chelicera, fang and eyes

The mature male above was found wandering across my floor in search of a female. For this species this is common behaviour at the end of summer and during the autumn.

If the female is receptive, and the male has passed the courtship test she will become relaxed and allow the male to insert his palp into her epigyne. Copulation can last just a few seconds or many hours depending on the species, the position also varies and depends on species. Usually the male inserts one palp, discharges it, then inserts the other. The female stores the sperm in her spermatheca, and it can be used to fertilise multiple broods. A few females will catch and eat the male after mating, but in most cases the male is not eaten, and will go off to try to find another female to mate with.

In some species the mated pair will stay together for a while, but mature males do not live nearly as long as mature females. It is then, once the male has died of old age, that the female will eat the male.

The female stores the sperm until she needs it, and this can be for as long as 18 months if conditions are unfavourable. However she will have to use the sperm before she moults.

Spider ballooning

Ballooning is done by small spiders and spiderlings. In the early summer it is done mainly by young spiders dispersing to a new area, and later in the year it is mainly adult money spiders that balloon.

To balloon the spider climbs as high up whatever structure it is on, turns to face the wind, and releases a few strands of silk. Then it lifts its body up holding on to the surface with just two front legs, and waits till the air currents carries it up.

Ballooning takes place when there is a very light breeze. Of course the spider will have no control over direction or landing place, and so many spiders perish as a result of ballooning.

Spiders can balloon to over 3000 m in height and still survive. They can travel great distances, and are often early colonizers after fire, disaster, etc.

How spiders eat food

Spiders cannot eat solid food. They inject or pour (depending on family) digestive juices into or onto their prey. These juices liquefy the prey with is sucked up leaving only the hard parts. They can eat quite a lot in one go, as the abdomen can expand. Also many species can go a long time without any food at all.

Old proverb

If you wish to live and thrive,
Let a spider run alive.

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