Comments on ID?

mortenoen · Post by **mortenoen** » Fri Mar 10, 2017 8:17 am

This is another one of my Baltic Amber Eocene period inclusion bugs. I'm starting to get pretty good on identifying my insects by now, but this one is a mystery to me, and here is why: I think it's the order of Coleoptera, the beetles. And I think it's a Weevil, or snout beetle i.e. Curculionidae Curculio. But here are some problems. The snout of my beetle is very long (of course indicating it might be a female) but it is also segmented. Note that the antennae are not on the snout (as on the Proboscideus) but barley vissible higher up, like the Glandium.So this fits with the european Glandium. But all these Curculio beetles have jaws or cutting tools at the very end of theire snouts,(to drill into nuts and lay eggs) while mine has flagellum, or 3 threads, possibly for feeling or tasting.And the snout does not curve. It's also tiny, only 1.5mm. So have I actually found an evolutionary dead end, or an extinct species?
I could ask on the bugguide.net, but they don't like European bugs over there, so I'm trying here first. Maybe some of you have seen something like it.

Pentax Q7, 25mm Rodenstock Omegaron f.4 @ f.4.7, 80 images, Stacked to 5 Dmap images, then Pmax stacked in Zerene (Thanks for that tip!). Immersed in VG.

Peter M. Macdonald · Post by **Peter M. Macdonald** » Fri Mar 10, 2017 12:06 pm

What you have here is some form of Hemiptera, with its piercing mouthparts on display. You can see that this is segmented. The snout of a weevil does not have this segmentation.

It is probably not possible to identify the specimen fully, due to the "milky" nature of the amber. This is caused by a reaction between the plant resin which makes up the amber and the moisture from the inclusion. It seems that the moisture originally formed an emulsion with the resin. As the water has been driven off as the sediments which contained the amber has matured, the chemical composition of the milkyness has changed somewhat, so making it difficult to determine whether the fats in the insect were also involved in creating the milkyness.

Peter

mortenoen · Post by **mortenoen** » Fri Mar 10, 2017 2:03 pm

Thank you so much Peter!

So I was not even in the right order

I have tried for an hour or so to find a Hemiptera with a very long rostrum, but no luck so far. I'm not giving up, only taking a break. Will be back when I crack this one. Those mouth parts are nasty business!

I knew about the milky part. I have a splendid book about it. It's complicated, and not well understood, but fluids and resin have to be in a perticular state for this to occur, and it's very usual in Baltic Amber, and almost always only on one side of the iclusion (90%). This fact has led scientists to belive that the sun also plays a part i this chemistry (i.e. that the sun "burns" the cloudyness away on one side). Very interesting indeed! And thanks once again!

MarkSturtevant · Post by **MarkSturtevant** » Sat Mar 25, 2017 8:28 am

I propose it to be a planthopper nymph (Hemiptera). The weirdly long proboscis can be explained by shrinkage of the abdomen. That is, the insect lost a lot of fluid, and its soft abdomen shrank by quite a bit.
Surprised and sorry that the people over at Bugguide were not more helpful since an ID to order and maybe to family would have been ok.

rjlittlefield · Post by **rjlittlefield** » Sat Mar 25, 2017 8:35 am

MarkSturtevant wrote:The weirdly long proboscis can be explained by shrinkage of the abdomen. That is, the insect lost a lot of fluid, and its soft abdomen shrank by quite a bit.

That sounds plausible, but I'm still bothered by the ratio of proboscis to leg length. Is that within range for current bugs?

--Rik

mortenoen · Post by **mortenoen** » Sat Mar 25, 2017 9:39 am

Thanks for all input. I would estimate that as it is, the proboscis is almost twice the length of the entire body. At first view I actually thought it was cerci because of the length.

MarkSturtevant · Post by **MarkSturtevant** » Sat Mar 25, 2017 10:58 am

Good point on the short legs, as that might help narrow down the ID. The less mobile ones in this group are rather stationary or nearly stationary parasites on plants, and they have short legs. A spittlebug nymph for example: http://bugguide.net/node/view/582874/bgimage There are others with shorter legs than that.

mortenoen · Post by **mortenoen** » Mon Apr 17, 2017 4:36 pm

I sugest this to be a Homoptera Aphidoidea, a Greenfly and a bug. A suborder of the Hemiptera. It is usual to find in Baltic amber, and the key described in Andrew Ross' book "Amber, the natural time capsule" (Natural History Museum, London 2009) fits perfectly. Thanks to this book a lot of my inclusions are now ID'ed