Insects Archives - Page 5 of 7 - A Year in the Valley

These are not caterpillars!

Technically not in the watermeadow, they were on an alder sapling in the top garden, these are the larvae of a Birch Sawfly (Craesus septentrionalis).

These larvae suddenly seemed to appear during the afternoon on the patio. Birch fly larvae feed in crowds on young trees, stripping the leaves of mainly alders and birches from late August to October. They have four rows of around ten black spots running down the length of their body and three pairs of legs followed by rows of false legs, which you can see in the photo.

There was conflicting information online – a different species of Birch Sawfly (Cimbex femoratus) had a plump green larva with a dark stripe running down its back, while Craesus septentrionalis is also known as Nematus septentrionalis, which itself is also known as the Hazel Sawfly. I also read that Nematus septentrionalis was formerly known as Craesus septentrionalis. It all seems a bit ‘mix and match’.

Unlike caterpillars, which only really eat single plant species, the sawfly larvae enjoy a varied diet of maple, hornbeam, hazel, ash, poplar, willow, rowan, alder, and birch. The larvae will pupate and then emerge as small, black adult Birch Sawflies.

UPDATE – From now till 10 March 2024, I’m going to post three times a week only. This is because there will be limited access to the watermeadow and also, I’m not expecting to see as many new species. I should still hit my target as I have been posting more than one species on many days so far. This will give a more accurate representation of the year than if I had relied on a backlog of summer observations to pad out the wintery days.

Daisy D

10 September 2023

Insects

Birch Sawfly

Burdock Gall Fly

It was worth taking a photo of yet another small fly, as this one turned out to be a different species again. This is a burdock gall fly (Terellia tussilaginis). They have this pale green colour and brown banding on their wings. The larvae live on burdock flowers, causing galls and live in the old flowerheads over the winter.

Daisy D

09 September 2023

Insects

Burdock Gall Fly

White-tailed Bumble Bee

I’m playing catch-up for the next few days, as I have a back-log of photos to identify and log (and also sciatica, so I am not tackling the steps down to the watermeadow). This is a white-tailed bumblebee on some toadflax. It is similar to the garden bumblebee and the buff-tailed bumblebee, but its bands are bright yellow, like lemon curd, whereas those of the buff-tailed bumblebee are more orange-yellow, and the garden bumblebee has beige stripes. They all have a white bottom, though the white-tailed bumblebee has the purest white.

They can all be found in a variety of habitats, as long as there are flowers present.

Daisy D

01 September 2023

Insects

White-tailed Bumblebee

Midges and Moles

Looking up to the alder treetops, I could see a swirl of midges scribbling in the sky and I couldn’t resist a photo. This is how I am recording all the tiny gnats and midges that will never pose for photoshoots – as one generic entry – at least until I get a better idea or opportunity.

And I loved that bit of clear blue in between all the mizzle and showers we have had lately!

Meanwhile, down at my feet moles have been busy digging their way round the watermeadow. We are never going to see an actual mole, but here is the evidence. We often have ‘evidence’ in the upper garden, too, and although they can be destructive, it’s a delight to know that moles are still around. I remember the school playing field studded with mole hills when I was at primary school but have rarely seen them since.

We wonder where the moles go in the winter, as they don’t hibernate. Instead they dig deeper into the ground below the frost and carry on eating earthworms until the spring when they build bigger chambers underground and rear their young.

But how does that work in a wetland habitat? Moles can swim and are adapted to live in a low-oxygen environment. Whilst they are not aquatic mammals, they can cope with a flooded tunnel, but will move to higher and drier ground if the ground becomes submerged.

Daisy D

31 August 2023

Animals, Insects

Midges, Mole

Bronze Shield bug – First Instar Nymph

I thought this striking bug was a type of ladybird, but it turns out that it is another one of those instars. It’s the first instar of the bronze shield bug, which due to its bronze colouring is quite difficult to spot. This species is widespread but not common.

The nymphs feed on plant sap and insects and are partial to caterpillars. New adults normally emerge from July, overwinter as adults, and then mate the following spring. So, it seems a bit late in the summer for a first instar, as we are told that there is only one generation per year.

Daisy D

30 August 2023

Insects

Bronze Shield Bug

Common Bluebottle and Flesh Fly

I had already seen a green bottle and had been expecting to see the blue bottle first. But, really, what’s the difference between them?

Size – the blue bottle flies are larger than the green.

Colour – metallic blue vs metallic green.

Breeding – both lay their eggs on dead and decaying animals, the eggs hatch in less than a day and burrow deep into their food supply. They are important in breaking down the carcases of dead animals, but cause contamination issues if they get into food production areas. Whilst green bottles have the same breeding habits, they are considered less of a nuisance as they are less likely to come indoors and are reliant on warmer weather.

Uses – Green bottles will also invade living tissue, which is bad for sheep, when they burrow through dirty wool, but good for humans where they are used in medicine to remove infected tissue to speed up healing.

Flesh fly – I think this black and white checked fly is quite attractive in a tweedy sort of way. It’s a fly I have seen around, but not really thought about. It’s not as iconic as the blue bottle, or as unexpectedly striking as the green bottle.

So how does this differ from the ‘bottles’? Well, mainly because rather than lay eggs in their food source, it deposits the first instar larvae (maggots) directly onto carrion, compost, excrement etc. The larvae prefer moist conditions but can be found in urban or rural environments. However, they are an outdoor species, so are not thought of as a nuisance. Also, note, they are omnivorous, so will eat up their veg, as well as meat.

Daisy D

28 August 2023

Insects

Common Blue Bottle, Flesh Fly

Moth Fly

This was such a tiny moth, that I nearly didn’t see it. Only it turned out not to be a moth. Moth flies are also known as drain flies and can be problematical as the larvae live in water and feed on bacteria, which means they can lurk around drains and bathrooms. Moth flies come in different colours – black, grey, or brown. You will notice that they rest with their wings ‘ajar’, not closed like most butterflies or open like most moths. Their life span is only around five weeks – up to 15 days in the larval stage, 20-40 hours to pupate and 20 days as an adult.

Daisy D

27 August 2023

Insects

Moth Fly

Clover Head Weevil

This weevil was really difficult to identify. It resembles the pepper weevil, which isn’t resident in the UK. But then I found the clover head weevil (Hypera meles). It has a distinctive red/sepia colouring with pale stripes, which varies in intensity. Very active in mid-summer it burrows into the soil on the warmest, driest days and goes dormant. This process is called aestivation and is done to help insects, amphibians, and fish deal with hot and dry conditions to stop them from drying out. The weevil then becomes active again in the autumn. It lives in meadows where there is clover, we have clover on our pathways and on the bank of the stream.

Daisy D

26 August 2023

Insects

Clover Head Weevil

European Drone-fly

I noticed this distinctive egg-timer shape on its back and two white stripes. The drone-fly is so called because it resembles the drone of the honeybee. The markings can be quite variable, but they have a pale face.

The larvae live in moist, nutrient-rich places – standing water, moist compost or sileage. The adults are found around flowers feeding on nectar and pollen. They are also known as flower flies.

Daisy D

25 August 2023

Insects

European Drone-fly

Common Green Shield Bug – 4th Instar

When I identified the dock bug, I learned that an instar was a stage between moults of the larvae of an insect. And this is the fourth instar of the green shield bug, which I could tell from the pattern on its shell and its shape, which is more rounded than the shield shape of the adult. There are five instars before the adult emerges.

UPDATE – You will notice that the green shield bug is on some water pepper. The water meadow is thick with flowering water pepper and water mint at the moment, as well as fresh grass. Presumably it is a fresh crop of reed canary grass, the old flowering grass having dried out, keeled over and mostly disappeared into the undergrowth.

Yesterday, I saw a frog hopping along the riverbank, but it was too quick for me – as usual. Other misses include a mouse or vole that ran across the path (Hard Knot Pass) in front of me and, what we think was the elusive green cricket flying up the garden towards a willow sapling growing at the foot of the bank (Vole County). Mr C and I were looking out from the decking and quickly rushed down the steps, but could we find it!! I think it must have gone into the undergrowth, as we didn’t see it fly away.

UPDATE PHOTO – Adult Common Green Shieldbug spotted 10/03/24.

Daisy D

23 August 2023

Insects

Common Green Shield Bug