There are five members of the Eristalis family likely to be found Dorset and they are all rather similar to the inexperienced eye! Quite often records will have an element of doubt about them as even specimens within the same species can differ in markings. The differences between species can be as slight as the width of the tibia (part of the leg!) or small markings on the wing. Not an easy task without catching specimens for microscopic identification.
Eristalis nemorum is one of the smaller members of the eristalis genus. It is very common and found in a diverse array of woodland and grassland environments throughout the late spring, summer and in to the autumn. The segements of the abdomen seem to me to be much more pronounced with white bands in this species than in the other small eristalis species, arbustorum.
In this species the male can often be seen hovering
Whilst bladder wrack is the best known of the wrack seaweeds the one most often seen is actually the channelled wrack (Pelvetia canaliculata). Growing freely near the high water line it is adapted to withstand long periods of exposure to the air without drying out. The weed that is out of the water the longest is usually blacker than the paler colour of that which is covered for longer. It does not have bladders for flotation as it rarely needs to float. It may appear to have bladders at the ends of its fronds but the swellings are not full of air, they contain a jelly substance and are the fruiting body of the seaweed. Channelled wrack grows in large masses and can be seen on sea walls, quays and piers as well as the upper reaches of rocky shorelines but each plant only grows to about 18 inches long due to the amount of time it is our of water. It is common around British shores and Dorset is no exception to that. In Scotland it has been used as cattle fodder but I was surprised to r…
The centre of the web is a funnel in which the spider waits. Around the entrance are lots of single strands, a bit like trip wires, that stop insects from an easy escape and gradually bring them nearer to the central funnel from where Agelena can strike!
I have heard people refer to these as Funnel Web Spiders which, of course they are not. Funnel Web Spiders are renowned for being very poisonous where as this spider is quite harmless (to humans).
The are extremely nervous creatures and quickly retreat in to their funnels which makes photographing them very difficult.