How many entomologists can you fit under a horse chestnut tree?

Preston Montford FSC Field Centre - Wednesday 15th June

Nine of us assembled in the car park at Preston Montford on a day of changeable weather. At the time of assembling it was dry. 

Preston Montford is an old country house that has extensive grounds of diverse character. In 1957 it became a Field Centre for the Field Studies Council. For some of us it was the main site of our activities under the Invertebrate Challenge and bio.fell projects and the neighbouring FSC offices now hosts the Tomorrow's Biodiversity project. More information about the centre can be found here and Tomorrow's Biodiversity here. The head of the centre had kindly given us permission to explore the grounds and do what we enjoy doing.

We were joined at the start by two members of the FSC staff, one a member of the Tomorrow's Biodiversity project and the other a recent recruit who was getting a feel for the activities of the her new employer. They were only able to accompany us for an hour or so and what an hour they chose.

After much preparation and chatting and only minimal searching in the car park we moved off towards an enclosed grassland with a mature lime and horse chestnut side by side. No sooner had we got there when the heavens opened.

"Only a passing shower" was the hope.

Initially we milled around sheltering under the two mature trees, which proved to be excellent umbrellas. Then we did a bit of leaf litter sifting.



It continued raining so I "bravely" ventured from the dry under the tree and did some vacuuming of the vegetation around the trees to put in the tray to look for things of interest.

It continued to rain. I looked at the sky hoping to see a glimpse of blue, but it was just various shades of grey.

Then the rain eased off and those who had sheltered under the lime emerged and milled around the horse chestnut and found a 22-spot ladybird with a white pronotum (normally yellow).



It started raining again, so we all huddled under the horse chestnut and waited.

Excitement. A slug was found on the main trunk.



This was identified as Arion ater as it writhed when it was stroked; the only slug, apparently, that does this. When I say writhe, first you have to be patient to see it and second it is a very slow process. Slugs are not known for their speed of action.

The rain stopped and our FSC colleagues departed. We emerged from the tree and made our way to the series of pools that form part of the sewage system at the centre.

The rain had left the vegetation sodden so sweeping with a net was not really an option as it resulted in a very wet net with very wet, bedraggled insects caught in it. Using a beating tray was a better option but only slightly as there was so much water about that the tray soon became a miniature swimming pool. The best option was to use our eyes, ears and cameras.

A pair of mating fold-wing craneflies Ptychopera contaminata were noted:



Nearby a Bloodvein moth was resting:



And on a leaf was this larva in its curious but wonderful construction. I have seen a photograph of a similar case before but cannot remember what creature makes it.



We moved on around the pools.



The SUN came out. We lunched.

By the third of the main pools there is an old high brick wall where the vegetation has been allowed to grow. A splendid bee hotel is sited at one end. This area provided a lot of interest as the sun and wall combined to provide a warm humid atmosphere.

A "jewel" wasp Trychrysis cyanea was found on the wall.



The hoverfly Anasimyia lineata was on the vegetation.



And another hoverfly Xanthogramma pedissequum s.l. was nearby.



Identifying the last hoverfly used to be easy but a similar species has now been found in Britain so it now needs a detailed examination to separate the two.

Then a pair of Early bumble bees (Bombus pratorum) were seen mating.



Apparently mating bumble bees are not seen very often so we were privileged to witness it here. The bees completely ignored the crowd that surrounded them and just carried on and on. Bumble bee mating is not a quick process. They eventually separated and went their own ways.

Unfortunately the rain started again and it was heavy. This time there were no large trees to shelter under so, after a few minutes, we decided to call it a day and head home.

My thanks to David Williams for allowing me to use some of his excellent photographs in this report.