Orchard Spiders Get Busy

Leucauge argyra is probably the most commonly seen orchard spider on the island, but it was still quite a treat to see a pair mating near Grand Case the other day. I noticed a pair of the spiders on a low-hanging tree branch with a bit of webbing on the leaves. The smaller male was tugging at the lines of silk, presumably to send a message of his intent to the larger female. Spiders often use this type of cue when courting, which varies from web-tugging to dancing and leg waving, depending on the species. The main benefits are establishing that the desired partner is willing to mate, and is of the same species, because each species tends to have a distinctive mating ritual.

In this case, the female was initially facing away from the male, but after some persistent signaling, turned around and spread her front legs, allowing the male to approach. As you can see in the photos, the male spider (on the right) has pedipalps full of sperm. Pedipalps are leg-like appendages in the front of the body, and the tips of the “loaded” pedipalps look like small red balls. The goal for the male is to inject his sperm from his pedipalps into the epigyne of the female, which is located on the underside of her abdomen.

It was a difficult thing to photograph, particularly due to the extreme heat, with just enough breeze to blow the branch in and out of focus, but not enough to cool down the photographer. Immediately after what I believe was a successful coupling, the male disappeared.

One Response to “Orchard Spiders Get Busy”

  1. Andrea Hoegg Says:

    Love the arachnids. I still have one at home I am trying to identify.