Thursday, 25 June 2015

A garden stretch spider!

It has been so pleasant today, warm and still, with high clouds. I had planned to do a little evening gardening and I was about to start trimming the olive tree when I noticed a busy spider web spinning. Wait, a stretch spider, Tetragnatha, a new spider for the garden! I rushed back home to fetch the camera and took some photos. I think it is a female, possibly adult. Her yellow abdominal stripe glowing with the flash. I couldn't bring myself to capture it for ID as I would have surely destroyed her web and spoiled her night hunt, so I might do tomorrow. I will update the post if I find out what species she is.

Wednesday, 24 June 2015

The patrolling Red Admiral

Since the beginning of June, Red Admirals have been well established, having returned from the Mediterranean in their one way spring migration. Females should be mating and looking for sunny nettle patches in which to lay their eggs. Males should be looking for receptive females to mate with. They will produce one or more broods in the summer. As temperatures drop in the autumn, butterflies will prepared themselves for the autumn migration and then they become very apparent in gardens, where they feed on buddleia and other nectar rich flowers. Male and female have the same wing colour pattern. If you have a good view of the abdomen when the butterfly is resting with its wings open,  a swollen abdomen will allow you to identify a female, but otherwise it might be easier to tell them apart by their behaviour in early summer.
  Last week, in the afternoon, I have flushed a Red Admiral from the same sunny spot on a grassy area amongst trees, where they were sitting day after day, exactly where I often found them last year. This afternoon was unusually warm and, as I left work, a Red Admiral sat on a low hedge on a wooded glade teeming with nettles in our university campus (above). It would sit and then fly up patrolling around the trees and chasing passing bumblebees in a similar way a Speckled Wood male would do, and then return to the same perch. I had never noticed this behaviour in the Red Admiral, but it appears that I had observed a male, and that red Admiral males actually defend territories. It might seem hard to believe that beautiful, fluttery butterflies actually engage in any kind of aggressive interaction. Indeed, butterflies have no offensive weapons other than their wings, and, butterfly contests, even when they are defending a territory are often perceived as chases instead of aggressive interactions. However, there is now abundant research showing territorial behaviour in a number of butterfly species. The important point is not the presence of an actual fight but the outcome: as a result of the behaviour the owner remains in the territory and the intruder flies away.    Royce Bitzer and Kenneth Shaw carried out research on the territorial behaviour of the Red Admiral on the Iowa University campus. They captured and marked individual Red Admirals with different spots of paint and observed their behaviour once released. They found that Red Admirals spend the morning feeding, but each evening males establish temporary territories for a couple of hours before roosting. Males spent most of their time perched, but occasionally patrolled their territory boundaries. They were not seen feeding. Birds or other butterfly species were chased in a linear way, but male intruders are chased upwards in a spiral. In Red Admiral chases, the owner often retains ownership and the intruder flies away. Good territories are likely to be an area containing resting spots from where passing females can be easily detected, usually with linear features (e.g. a pavement or a few trees in a line). The maintenance of these temporary territories could allow better access to receptive females moving into their roost, as mating is thought to happen in the roosting sites in trees.
A particularly bright red and intact individual, maybe the result of a first local brood?
Two days later a much more faded individual with tattered wings, on the same favoured spot on the grass.

More information
Red Admiral and Painted Lady Research Site. Here.

Bitzer, R. J., & Shaw, K. C. (1979). Territorial Behavior of the Red Admiral, Vanessa atalanta (L.)(Lepidoptera: Nymphalidae). Journal of Research on the Lepidoptera, 18(1), 36-49. here.

Pholcus before and after laying eggs

The first female Pholcus phalangioides laid eggs at the top of the porch last week. The gravid female I was following, which lives under a shelf in the outside toilet was still without eggs yesterday. This morning when I checked, she had laid. Check her abdomen before (below) and after laying (top).

Friday, 19 June 2015

Insects at the University Woodland Area

This afternoon, I joined James Gilbert and Robert Jaques to search for hoverflies, bees and other insects in the woodland area at the University grounds. It was overcast and mild, and a surprising number of insects on the wing. A few Hogweed umbels were a big attractions, as were the buttercups (a handsome Helophilus pendulus above).
The Batman hoverfly, Myathropa florea on hagwort
Nettle tap moth
A male Bombus lucorum swinging from the flowers.
This is a dronefly, Eristalis pertinax.
There were at least three male longhorn, Nemophora degeerella, moths about. They danced as they flew high up. It looks like quite a challenge to fly with such oversized antennae, which presumably attracts the female's attention. This one rested on nettles for a while.
A female Marmalade fly, Episyrphus balteatus, with extended ovipositor.
And to finish, a Speckled Wood. I rarely see these butterflies nectaring. They have a short tongue and like to lap honeydew on tree tops, but the exposed, flat flowers of the hogweed seem to appeal to them.

Sunday, 14 June 2015

A wander for millipedes

We had a walk in our local cemetery today. The eastern part of the cemetery is the oldest and the area has been pretty much left to run wild for many decades. There are huge trees embracing headstones and ivy also covering them, so sometimes it is not obvious you are in a cemetery. It is a muddy and wild place to explore. The cemetery has a lot of dead wood left on the ground and loose stones, which makes it a great place to search for millipedes: today's wild thing.
 We pushed through nettle beds, brambles and hogweed, waded through muddy puddles, crossed others by walking on logs and did a little millipede collection on the way. The wet weather had also brought some interesting fungi.
 Millipedes do often go unnoticed, as they live under the cover of logs, bark and stones, on leaf-litter or in the soil. They have many similar body segments and a pair of legs on each segment. Despite their name, no species reaches 1000 legs. Millipedes have defensive glands and they often open into colour spots on the side of the body called ozadenes. There are about 60 British species of which we found four.
Pterostichus niger ground beetle, centipede, Discus snail under stone.
Tachypodoiulus niger is very easy to identify as it has a black body and white legs. When disturbed it wriggles like a snake. I often find it on dead wood.
In contrast, Cylindroiulus punctatus curls up when disturbed.

Here is once stretched. C. puctatus has a characteristic face mask between its eyes and a clubbed tail end.
In Blaniulus guttulatus the ozadenes are bright red. This species has no eyes and it's thin and tiny
Here are two Blaniulus guttulatus under a stone. They are often found together in large numbers.
A Flat-backed millipede, Polydesmus sp.
The Sycamore embracing a headstone.
A mushroom on yew that looked like mango ice cream.
Lots of Jelly ear fungus.