Interesting 7-spot Ladybird

[JRsbugs]

Hi,

I only got one pic of this before it flew, but I noticed it's head appeared to be all black, although I couldn't be certain there's no white showing on what is visible. The white patches on the pronotum are mostly black too, and the white areas around the central black spot of the elytra are missing.

I have seen an occasional Ladybird with damaged elytra, but this doesn't look like damage. Has anyone seen one like this?

Janet

[Dogghound]

Probably one which emerged/developed later on in the year, the lower temperatures subsequently resulted in more melanin being produced giving it a darker appearance. The elytra look almost clear to some extent. I think its to do with the conditions of its development in this one. There are white(grey) bits on the corners of the pronotum.

[Klaas Reißmann]

Hi Janet,

deffinitely very interresting. Haven't seen one like this before. There even is the white marking around the scutellum missing. would be something interresting for the variations of Coccinellidae of kerbtier.de. You should make an offer to Christoph. He surely will be glad to show this picture.

Regards
Klaas

[JRsbugs]

Dogg, that could be the case, but have you seen any like this? I keep hoping I will see it again but it's been too cold the last two days.

Hi Klaas, I did wonder if Christoph would like to show it, I even tried to flip it vertically but unless he has a programme which can straighten it it will remain crooked. I guess that wouldn't matter, it's not a bad shot! It's interesting that you have never seen one like it given your years of experience! I'll send it to Christoph.

[Dogghound]

Originally Posted by JRsbugs

Dogg, that could be the case, but have you seen any like this? I keep hoping I will see it again but it's been too cold the last two days.

No , ive seen several with spot abberations but nothing like this one.

[JRsbugs]

Originally Posted by Dogghound

No , ive seen several with spot abberations but nothing like this one.

Even more interesting!

I got a 2-spot with 3 big spots too, but I thought the 3rd spot was damage until I saw the pic! It was inside, I put it out after taking some pics. If Christoph wanted that too I didn't get a direct shot from above, but it's nearly from above. I have sent the 7-spot to him and mentioned the 3 spotted 2-spot, apparently they can have none or up to 16 spots but I haven't seen one with more than two spots before.

[Bruce Williams]

Interesting find Janet. Other than the size of spot I've not found this species to be particularly variable - I've certainly not come across anything like this one. The translucent elytra is also quite interesting allowing us a partial view of the neatly folded wings.

Bruce

[JRsbugs]

I hadn't thought about the wings showing through Bruce, although I saw the diagonal lines. I checked some other pics, some do show a little translucency but not as much as this one. Maybe there's not enough calcium in their diet.

Maybe we can call it an Extra-scarce Ladybird? I am getting some unusual ones!

[Paul mabbott]

It's quite common to be able to see the hindwings through the elytra: mostly, of course, when the beetle has recent eclosed and before hardening and colouring of the elytra. However, it also happens when the elytra are thinner than usual which, presumable is due to nutritional factors.

The absence of white markings is intriguing and I don't recall seeing the like. It is odd that it has occurred on both elytra and pronotum (although there is a shadowy grey area on the pronotum ?) since the sequence of pigmentation o the two body parts is different normally. When e talk of pigmentation we tend to think about the black and red (yellow &c) colours but, of course, the white is also a pigment and has to be produced by chemical reaction. It is possible that white formation is in a different layer of the cuticle which may be absent here .... or whatever. Unfortunately, I can find nothing in my literature about the process of white pigmrtation. I shall ask around!

[JRsbugs]

Klaas, Christoph has now put the pic on his site and he managed to straighten it!

Variability of elytral color patterns in ladybirds (Coccinellidae) - kerbtier.de

Paul, thanks for the thoughts on the whatevers! I also had thoughts on the whatevers, I joined the Yahoo beetle group (you probably noticed) and had two responses, one person had seen one similar last year although he said they were not common.

The other person gave a few more interesting details on distribution, and thoughts on what is happening. This is what John Muggleton had to say:

The further east one goes geographically the more variable the colour pattern of
Coccinella 7-punctata becomes, so that all black forms can be common on the
Indian sub-continent. There are also forms where the elytra are black but the
pronotum retains its white markings. I have only once found an all black
specimen in the UK. However your specimen does not seem to fit into this
classic picture. In your photograph the white markings on the pronotum are
still clearly visible but are suffused with a dark pigment. The red on the
elytra also seems to be suffused with a dark pigment. So I am not quite sure
what we are dealing with here. It might be the result of some developmental
problem with the pigmentation rather than an inherited colour variation. One
would need to breed from specimens to discover whether the colour variation is heritable.

My response.. this gave me food for thought!

Thank you for the information John. It is interesting to note the darkening
towards the east! But at what point do we start to get to the east, the 7-spot
is also in the US and the world is spherical. I wonder if that is due to
genetic influences, or to do with heat? Could it also be due to diet, that is
nutrients gained eventually through insects and the plants which they consume,
the plants having taken nutrients from the ground. There are geographical
variations in humans so why not beetles?

This makes me wonder if the rarer variations of the 7-spot found here are
imports brought in with foreign plants. I know two nearby nurseries get plants
from Boskoop in Holland, one also gets bamboo from south of France so I imagine
that is a possibility. I live near Lincoln, I wonder if the dark variations
found in the UK are wide spread?