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2. Specimen Discussion
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3. sedge larva

I've found some sedge larva (?) in a small stream in Wales, living in small tiny, tiny pebbles, like a tunnel! I do recognize the head and legs and would love to know a little bit more about them! Some also had sticks glued to the pebbles, looking like grasshoppers that's drowned! I shall look forward to hearing from you on my e-mail - helenemills2@yahoo.co.uk - Thanks Helene Mills

Helene-

Caddisfly larvae are generally classified as net spinning, free living, or case building. The netspinners build a retreat incorporating a silken net to capture food, similar to a spider web, only underwater. The freeliving build no shelter. The casebuilders build either a portable or fixed case for their protection.

A species which builds cases generally constructs them so similarly, that a case can often be identified to genus level simply by virtue of its shape and the materials used in its construction.

Does that have to be Rhyacophila because the larva is green. Dave Hughes calls hydropsyche larva, (spotted sedge) green rock worms as well. Or has that been keyed out further?

Hydro's are quite different looking. They have notable gills along the underside of the abdomen. Many Rhyaco's have that brilliant blue-green coloration. Hydro's are normally duller in color, usually tan to olive, although some can be a fairly bright green.

That's the trouble with common names. In this case "green rock worm" is a good description, but unfortunately for many critters.

Thanks Paul.