Wednesday, June 14, 2006

Mystery, Mystery, Mystery?

Wayne, Bev, Somebody? Please help. I have some mystery grub/insects larvae or something that I cannot identify. The first larva is currently eating on our goldenrods. I suspect that it is eating both Tall Goldenrod (Solidago altissima) and Canada Goldenrods (Solidago canadensis). That it is eating goldenrod does not bother me too much, but I would like to know what it is.
You can judge the size by the left part of the photo where I left my thumb and finger in the picture. I have not seen any of the tens of thousands of the larva at a much larger size.



The second larva/thing I have no clue about other than it appears to have 6 legs or maybe something with 6 legs is eating something else? I found it on a blade of grass all by itself. No other examples were around. (I put in on a Milkweed simply to have something large enough for my camera to focus upon.) The beast is about the size of a small bean or very large pea. The yellow part moved up and down a bit but there was no other movement even though I picked the blade of grass and moved it across the field to a milkweed for photography.



OK, I have found a photo in Caterpillars of Eastern North America that seems to fit this third caterpillar fairly well. With it I would just like some second opinion. I think it is a Fall Armyworm caterpillar (Spodoptera frugiperda). It was chewing on White Sweet Clover.

6 comments:

bev said...

Well, your first pair of photos are of the larvae of a species of Trirhabda beetles. We have tons of them around our place this summer and they are really doing in the goldenrod. I postd a note to the local nature listerserv for my area this morning, asking if others had noticed high numbers of Trirhabda larvae on their goldenrod and have received one reply so far from a member who said they noticed lots too. Anyhow, there's a photo of one on this webpage -- keep in mind, there are more than one species of Trirhabda. They turn into a yellow and black beetle -- here is a photo which I took of a pair last August.

As for the other two photos, I have no idea about #2. Whatever it is, it looks very weird. I guess I'd have to get a better look at it. It's possible that it's the larvae of some kind of scarab beetle as they do have legs at the front by the head, but that's a pretty jumbled up looking creature, so I can't say for sure.

Regarding #3 - again, I'm not sure of the ID. It might well be an armyworm of some kind. It thought the Fall Armyworm had some striping along the sides and a very dark head, but I think there can be a lot of variation. Unfortunately, many of the less distinctively marked caterpillars are difficult to ID. That's not really all that surprising considering the number of species of moths that we have.

Good photos off all of these insects.

Wayne said...

Wow - OW, I wouldn't have guessed those first two were beetles but I sure do trust Bev's diagnosis especially after looking at the link she gave. Sharp!

That middle one is, as Bev said, quite a jumbled up critter. I have no idea.

And I'm afraid I can't help with the fall armyworm possibility. I do recall that in Florida we lived in fear of armyworms, which can turn a pasture of grass into stubble in hours.

bev said...

O.W. - I've been thinking about the armyworm some more. Do you have a shot of it from the side so that you can see the legs? When ID'ing caterpillars (or similar larvae), a view of the leg arrangement is often useful for figuring out whether it's a lepidoptera larva, a sawfly larva, etc...

Clare said...

Okay, this is just a thought as I really don't know, but for the second creature you have two. The yellow part looks like a pupae of some sort, with the head end facing to the right. The darker parts with the legs appear to be something else entirely (the adult emerging? although it seems to be oriented wrong for that). Perhaps an emergence gone wrong?

Endment said...

Try this site
http://www.whatsthiscaterpillar.co.uk/america/index.htm

Ontario Wanderer said...

Thanks to all for the information you were able to give. Sorry Bev, I don't have any better photos of the "armyworm." If I find another, I shall try to do a photo of leg arrangements. Thanks Endment for the site. I shall look as soon as I have a chance. I've been away from the internet for a few days and have lots of catching up to do.