Here be dragons!

Yesterday we had our second Young Naturalists catch up via Zoom, looking once more at the moths in the light trap using the digital microscope and also at some pond creatures I had caught out of the new dipping pond first thing.

We talked about dragonfly and damselfly nymphs and had another look at an exuvia I had found floating in the pond (the dried outer casing left behind when the nymph finishes the aquatic stage of its lifecycle), looked at lesser and greater waterboatmen and a couple of different diving beetles and a diving beetle larva, talked about what materials cased caddisfly larva use to make their cases (the one I caught was thinner and more streamlined than the one in the photo below, living in a tiny tube made of pieces of reed or leaf), talked about the feathery gills on the baby newts or efts which enable them to breathe underwater and are absorbed as they develop, and watched a whirligig beetle whizzing around on the surface of the water – they definitely have the best name out of all the pond creatures!

I didn’t get round to taking any photos of the creatures as a number were trying to escape whilst I was talking about them, so they were swiftly released back into the pond whilst volunteer Nigel chatted through the moths he had caught in his light trap at home. Here are some photos I took a while ago now, it was quite nice to go pond dipping again!

Nigel had also prepared an A to Z of birds quiz which kept the group entertained, especially as not all of the birds were native to this country. Bonus points were also awarded for additional questions about each bird, so I think the group learnt a thing or two, including where Nigel has been on past holidays!

After a very soggy start to the day the sun came out after lunch so I went for a walk around the reserve. In the meadow I was treated to some great views of a female Black-tailed skimmer, who I had disturbed when passing but seemed content to settle again on the grass:

Female Black-tailed skimmer

Female Black-tailed skimmer

Seeing dragonflies and damselflies at rest is one of the best ways to tell the two apart, dragonflies rest with their wings outstretched, as above, whereas damselflies rest with their wings held together over their abdomen or body:

common blue damselfly

Common blue damselfly at rest

I also found a Mint moth, Pyrausta purpuralis enjoying the ox-eye daisies. Although the grass and flower stems turned brown very quickly with the absence of rain, the flowers themselves are still blooming.

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Mint moth, Pyrausta purpuralis

On my way up to Lapwing Hide I saw what I first thought was a bumblebee, but on closer inspection realised it was a bumblebee hoverfly.

Bee mimic hoverfly volucella plumata

Bee mimic hoverfly, Volucella bombylans var. plumata

This hoverfly is an excellent bumblebee mimic. There are two main varieties, Volucella bombylans var. plumata seen above has yellow bands and a white tail, mimicking the Garden, White-tailed and Buff-tailed bumblebees whilst Volucella bombylans var. bombylans is black with a red tail, mimicking the Red-tailed bumblebee.

Mimicry reduces the chances of the fly being predated because it resembles a bee. In addition, the females lays their eggs in the nests of bumblebees and wasps where the larvae feed on the nest debris and occasionally the bee larvae as well.

On my way back to the Education Centre I was lucky enough to spot another female Black-tailed skimmer, who also posed beautifully so I could take a really good look and take some more photos:

Female Black-tailed skimmer 2

Female Black-tailed skimmer

Female Black-tailed skimmer 4

Female Black-tailed skimmer

Female Black-tailed skimmer 3

Female Black-tailed skimmer

Dragonflies have amazing vision, which they use to locate and catch insects whilst on the wing. Like most insects they have have compound eyes: each eye contains several thousand individual facets, with each facet containing a tiny lens. Combining all the images from each lens makes their sight better than most other insects.

Their eyes are holoptic, which means they meet along the middle of the head and take up most of it, wrapping around the head from the side to the front of the face. In comparison a damselflies eyes are also large, but they do not meet and there is always space between them. This is known as dichoptic and can be seen on the Banded demoiselle below:

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Banded demoiselle

Our Young Naturalists group is kindly supported by the Cameron Bespolka Trust.

30 Days Wild – Day 14 – Garden Safari

I spent almost all of the day in the garden, working in bursts until I got too hot, then just sitting back and watching. There was a lot to see, twice groups of crossbill flew over, these birds breed very early in the year and then the families set out to look for ripening cones from which to prize the seeds. In some years, when the breeding season has been good but the cone crop is poor, birds will fly very long distances, hundreds or even thousands of miles. These are known as irruptions and are characteristic of species that exploit locally abundant, but unreliable food sources.

The main interest was the insects though, the pond continues to draw in dragonflies and this fine male broad-bodied chaser spent most of the day nearby.

broad-bodied chaser

broad-bodied chaser (male)

Whilst looking in the flower border at something else this recently emerged emperor dragonfly was spotted, not by me, although I was looking at something about 15cm away!

emperor

Emperor

As it was so close I got a few closer shots of the head and eyes. They have almost all-round vision with thousands of tiny facets to the eyes, which also have different coloured zones.

emperor head

emperor head

It was not just dragonflies though, there were meadow browns in the mini-meadow and a red admiral on privet flowers, a small white attempting to lay eggs on the cabbages was less welcome though. The wild carrot is now coming into bloom and attracts quite a few species, including a second garden record of the mottled bee-fly, first seen a few days ago.

heath beefly

mottled bee-fly

Beetle included a Welsh chafer on a pink bistort flowerhead.

Welsh chafer

Welsh chafer

Lots of bees mostly evaded my camera, but I did get this male leaf-cutter bee resting on the side of the bee hotel, I confess I totally failed to identify this and had to be put onto the right course, I still find bees difficult!

Hoplitis claviventris 4x3

leaf-cutter bee (male)

However prize of the day goes to an especially brilliant bug. I was working near the house when I was called to see “A red and black shieldbug” an exciting prospect as there is a recently colonising species spreading at present. However I was in the middle of  a task so had to wait a couple of minutes before going over, luckily the bug was still there and it was an ornate shieldbug.

ornate shieldbug

ornate shieldbug

A species which is slowly colonising the south coast, something to look out for on plants of the cabbage family, this one was on rocket in our salad patch. Unlike some other species people ask us to look out for this one is pretty much unmistakable and really stands out, although it does come in various colour forms, so they don’t all look like this one.

 

 

30 Days Wild – Day 13 – The Eyes Have It

After the long sunny spell of lockdown we are now in a spell of old fashioned English summer weather, a bit of sunshine then a shower or even a thunderstorm.

silt pond

Approaching shower over the Ivy Silt Pond

When the sun comes out it is strong and very warm, these conditions are actually good for insect photography as the insects need to warm up after each cloudy spell meaning they are basking a lot more than in continuously sunny conditions. The timber of the planters outside the Centre make an idea spot to warm up and are being used by lots of species.

leaf cutter bee

leaf-cutter bee

I know Tracy has already posted some pictures of the green-eyed flower bee, but prepare yourselves for another, as they are very smart little insects.

green-eyed flower bee

green-eyed flower bee (male)

The eyes of many insects are very large and provide a huge field of view using an array of separate element arranged together in a compound eye. This is evidently very effective  enabling them to move at speed, through dense vegetation and often backwards or sideways. In some insects the eyes are patterned or coloured, the green-eyed flower bee is both as are the horseflies.

Tabanid

band-eyed brown horsefly Tabanus bromius (male)

This is a male horsefly and so it won’t bite, like a lot of male flies it has much larger eyes than the female providing very close to all-round vision. The size of the eye facets also varies across the eye surface, sometimes in ways that will identify the species. It seems that the larger facets give better acuity. Male horseflies feed at flowers, so not too difficult to find, the large eyes are for finding and  identifying females and avoiding predators as many are large and tempting prey for birds. Horseflies are also very fly fast and it seems they can process visual information much faster than we can allowing them to navigate between obstacles at high speed. The males of many species also perform dance flights, often in the very early mornings, long before the day has warmed up.

I made a site check walk around the reserve, which told me that the rain has produced a spurt of growth in brambles and next week I will need to get out and cut the path edges again. I also found a “new” pyramidal orchid, that is one somewhere I had not seen before and a very fine example it was.

pyramidal orchid

pyramidal orchid

The marsh thistle is just coming into flower, it comes in two colour forms, this being the pale one and is a plant I always associate with silver-washed fritillary, as they seem particularly fond of nectaring at the flowers.

marsh thistle

marsh thistle

Although I ran the moth trap there was not a great deal caught. In the great days of the Victorian moth collectors they did not have lamps to attract moths in any quantity and so found lots by looking for and then rearing larvae. I found this caterpillar on an oak branch, checking in the excellent and recently published Field Guide to Caterpillars by Barry Henwood and Phil Sterling, I concluded it was almost certainly a maiden’s blush.

maiden's blush

maiden’s blush (I think)