Dear Readers, I don’t know what you were doing yesterday (the hottest day of the year so far here in London) but I and a group of intrepid spider spotters of all ages were out in Coldfall Wood looking for spiders with expert arachnologist Edward Milner. The number of species of spiders recorded in Coldfall Wood is 141 at present (with 2 new species found today), so it just goes to show how complex the web of life in woodlands can be.
First up is the Bird Dropping Spider (Cyclosa conica), which has an absolutely distinctive abdomen. It is a tiny spider, so it was helpful to have Edward’s hand lens to see the fine detail. As is often the case with small invertebrates, it’s the detail that’s so exciting – the white patterning on the spider, plus its habit of sitting in the middle of its orb web with its legs tucked in, makes it look like a bird dropping or a piece of discarded food. It was a new one for me, and I suspect for the rest of the group (photograph above)
Next up is a buzzing spider and a new species for the wood, Anyphaena numida. During the breeding season, the male taps a leaf, producing an audible buzzing sound. We already had a record for a different species of buzzing spider (Anyphaena accentuata) but this one is being seen regularly in the London area now, having made the jump from mainland Europe. It will be interesting to see if it becomes more common than the established species. Note the ‘boxing glove’ structures at the front of the spider – these are pedipalps, which the male spider uses to transfer sperm into the female. Truly the sex life of spiders is a complicated thing!
Then there was a mesh/blue web spider, Dictyna uncinata. This is another tiny spider that makes its small, intricate, fleecy web in vegetation or amongst leaf litter on the ground. Under the hand lens you can see the pattern of white hairs against a brown background.
But not all the spiders were tiny. We managed to see one of my favourite spiders, the black lace-weaver (Amaurobius ferox).
Although not very big, this is a magnificent spider. The one that we saw looked almost jet black. The web, when new, has a lace-like appearance and a blue tinge. This is a spider that practices matriphagy – in other words, the spiderlings will cannibalise their mother after hatching.
Then there was this spider, apparently known as the ‘Silver Stretch Spider’, at least in North America, and as one of the long-jawed orb weavers over here. It has a distinctive long thin abdomen, and long legs. On the web, the spider forms the shape of a stick, which makes it difficult to see. Over 60% of its diet in one study was mosquitoes, with an average of 3.7 mosquitoes consumed every day through the summer season.
And finally, I can’t leave the description of our walk without a quick chat about another orb-web spider, Metellina segmentata. This smallish spider has the most exciting love-life. The male is attracted to the female by a pheromone that permeates her web, but once he’s arrived, he has to be careful – males have been seen to wait for in a corner of the web for up to a month before approaching the female. What’s going on? The male is waiting for the female to have caught a large fly so that she won’t be hungry when he approaches. In a twist worthy of Machiavelli, if another male is also waiting for the female one male may kill the other, truss him up and leave him as a ‘gift’ for the female to feed on. Once the female at least seems to be full up with food, the male will approach and try his luck. During all this time, he hasn’t been able to eat at all. It’s pretty clear that being a male spider is not a walk in the park.
So, all in all it was a great walk, with many other spiders and invertebrates found, lots of questions asked and most of them answered. There was a general lessening of fear in people who were nervous about spiders, and hopefully a greater understanding of their variety and the diversity of the ways that they live. Plus, it was wonderful to watch the enthusiasm of the children for the spiders and for all the little creatures living in the leaf litter and the dead wood and the plant life. It’s so important to kindle that flame of interest in the young, and then to nurture it. We need all the entomologists that we can get.