Arthropod Order Isopoda (Sowbugs)

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Taxonomic Navigation -?-

Kingdom Animalia (Animals)

» Phylum Arthropoda (Arthropods)

» Class Crustacea-Malacostraca (Crayfish, Scuds, and Sowbugs)

» Order Isopoda (Sowbugs)

Family in Isopoda
AsellidaeCress Bugs	2	6

Common Names

Match	Common Name
	Sowbugs
	Cress Bugs

Pictures Below ↓

Sowbugs are not quite as prolific or as important as scuds (Amphipoda), but in certain waters they are more common and serve the same role.

They should not be imitated with the same patterns because they are much more wide and tend to sprawl their legs to the side instead of tucking them neatly under the body. They crawl around instead of swimming, so they are probably best imitated with a dead-drift (Dead-drift: The manner in which a fly drifts on the water when not moving by itself or by the influence of a line. Trout often prefer dead-drifting prey and imitating the dead-drift in tricky currents is a major challenge of fly fishing.).

They produce new broods once every two months, allowing them to populate a stream very quickly if enough food is there to support them.

This order also includes popular terrestrial (Terrestrial: Insects which live on land and are fed on by trout only when they incidentally fall into the water are known as "terrestrials" to fly anglers, and they're very important in late summer.) species commonly known as pillbugs or rolly polies. They aren't known to be relevant to fly fishermen.

Pictures of 2 Sowbug Specimens:

Caecidotea (Cress Bugs) Sowbug Adult

View 3 Pictures

Collected January 13, 2004 from the Namekagon River in Wisconsin
Added to Troutnut.com by Troutnut on January 25, 2006

Caecidotea (Cress Bugs) Sowbug Adult

View 3 Pictures

Collected January 31, 2004 from unknown in Wisconsin
Added to Troutnut.com by Troutnut on January 25, 2006

Recent Discussions of Isopoda

Some Photos for Fred 4 Replies »

Posted by Martinlf on Jan 26, 2011

Last reply on Jan 28, 2011 by FredH

Do these look like the bug you ask about in your post?

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Jargon Defined:

Broods: When a species produces more than one generation per year, each one is called a brood.

Dead-drift: The manner in which a fly drifts on the water when not moving by itself or by the influence of a line. Trout often prefer dead-drifting prey and imitating the dead-drift in tricky currents is a major challenge of fly fishing.

Terrestrial: Insects which live on land and are fed on by trout only when they incidentally fall into the water are known as "terrestrials" to fly anglers, and they're very important in late summer.

Useful References:

Schwiebert, Ernest G. 1955. Matching the Hatch. MacMillan Publishing Company.