16-spot ladybird - showing comb-like structure on mandible

[Bruce Williams]

Thought some of you might be interested...

Pics are of a 16-spot ladybird (Tytthaspis 16-punctata). It measured ~3mm.

The pic of the underside of the insect includes a full resolution insert showing the comb-like structures on the mandible which (I've read) are used to comb up fungal spores.

Pics were taken in my garden (Northants).





Bruce

[asheleaf]

great pictures & info. thank you for sharing

Ashe

[JRsbugs]

Hi Bruce, I have yet to see a 16-spot unless I have mistaken one for a 14-spot!

Nice shots I agree, great to see the detail of the combs. I got something similar once with a Keroplatidae gnat feeding on Ivy leaves.

Janet

[Jason Green]

Afternoon Bruce,

Yes, great detail, you don't often get to see the detail of the hind femora like that. The comb-like structure you have high-lit is actually the inner-margin of the maxillary palp's terminal segment. Same function though I'm sure (but not one I'd heard about).

Janet - sweep about in long grass, particularly on a hot day. You may even find the odd one basking on a log in such areas.

Take care,

Jason

[Ukwildlifeo]

Excellent stuff. I must try the extension tubes on something other than pond creatures!

[Bruce Williams]

Appreciate your comments folks.

...and Jason thanks for pointing out my error. I've Googled (as you'd expect) and of course you are absolutely correct. What I thought were the mandibles are in fact the terminal segments of the four segment maxillary palps.

I've since seen a drawing in the Naturalist Handbook #10 that may show the comb-like structure on the mandible. It (the comb) does look very similar to the comb on the maxillary palp but of course they (the combs) may or may not perform the same functions. Anyway here's a drawing of the mandible based on the illustration I mentioned:



CAUTION: I should add that I am useless at following identification keys so it is quite possible that the illustrated mandible may be from an entirely different species of ladybird.

Bruce

[Bruce Williams]

Here's another view of the underside that may show the mandibles. Fairly confident but would appreciate confirmation:



Bruce

[Jason Green]

Not sure! Could be. The palps are used to guide and direct food into the mouth, and so the mandibles could be further back between their bases. I've done a bit of mandible/maxilo/labial palp stuff with bees/wasps in recent weeks but never had to touch ladybirds entomologically so I'll leave it to someone more experienced to say. Where are the labials, too!

An amazing set of images

[JRsbugs]

I've cropped some shots of a 7-spot from 2009 & 2010 which might help show what's going on..

[Jason Green]

Your second image shows the maxillary palps (segs 1-4) and the labials (penultimate and terminal, at least) nicely. I think however the mandibles are obstructed by the clypeus. A real up-and-under job to see them! Pop one on it's back to see when you get the chance, like Bruce has done here.