Insect Picture of the Day

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Here we have a male funnel web weaver trying to work out the delicacies of propagating the species without his specimen becoming a delicacy. The female (blurry, upper right) has already mated this year, but she’s not about to turn away new suitors. Female spiders keep egg and sperm separate after mating, and can use the sperm from a single mating for several years to fertilize their eggs. If a better suitor comes along, she can eject the old sperm in favor of the new, and if a poorer suitor comes along there’s always the potential for eating him. It’s really a win/win for her either way.

The male, upside down in the lower left, is easily distinguished from the female by his smaller abdomen and most importantly, his pedipalps. They are the large dark orbs in front of his face. If you look at the female in the upper left, her pedipalps appear to be little more than a 5th pair of tiny legs. But on the male they are large and distended. If she accepts his suit, he will transfer some of his sperm to his pedipalps, and then reach across her body to deposit it directly on her sex organs.

Of other interest in this picture, this web is about six inches away from the doorknob of my front door. As you can clearly see, I am a terrible housekeeper. More importantly, you can see that the owner of the web has done a brisk business in midges all Summer long.

This photo actually shows an interruption of their courtship: the male had been on top of her web and approaching her when I opened the door. The movement of air currents or vibrations spooked the male, who was carefully listening to the web for the strong vibrations of a spider charging across the web to eat him. He ran underneath for protection; most web owners consider the underside to be dangerously exposed territory and won’t pursue there.

She’s stilll out there, even though the nights are freezing here and about the only food animals left are other spiders. The front door faces East, making a nice light trap in the mornings. I put a thermometer out there to measure it: I am writing this post in the morning, and right now it is 5°C/42°F outside but the thermometer on the front door reads 17°C/62°F.

I don’t know if this is the case for funnel web weavers, but for most spiders this size, the females live for a few years while the males die off each winter. I’ll probably sweep out the front porch in a month or two when it’s too cold to function even during the day. This will give all the front porch dwellers (two funnel web weavers, a praying mantis and at least two hunting wasps have built nests or laid eggs there) a clean habitat come spring.