Brachycentrus
Larva 3
Size: 9- 12 mm
Body: Light cream/white, sclerites cover first two thoracic segments, tiny sclerites on third
segment. Larvae lack humps on either top or sides of first abdominal segment.
Legs: Dark brown
Case: Four-sided, neatly constructed of wood and plant material. Described as “chimney like” or
“log-cabin style”.
Larva Look Alikes 3
Larva Look Alikes:Brachycentrus larvae construct a distinctive four-sided case made of strips of wood
and plant material. The only other caddisflies that make a similarly four-sided case are some species of
another common caddisfly, Lepidostoma sp., and those cases of the latter are constructed of cut squares
of plant material rather than of thin strips.
Adult 3
Size: 10 to 12 mm
Body: Highly variable, bright/light green to very dark grey-brown
Wings: Highly variable, light tan to medium grey-brown
NOTE: Examination of mouth parts, legs, and thorax under high magnification is
necessary to reliably identify this caddisfly to genus. Collection of representative adult
specimens is highly recommended for confirmation.
Adult Look Alikes 3
Adult Look Alikes: Owing to variability in coloration within this genus (from light green to almost black)
and general similarity in size and color to other caddisflies, collection of representative adult
specimens is highly recommended for later examination under magnification.
Habitat & Distribution 3
At least five species of Brachycentrus inhabit flowing waters of central New England.
Among these, B. numerosus and B. appalachia likely produce the largest hatches and
are therefore of the most importance to anglers. B. solomoni (also known as the black
caddis) and B. americanus may also be locally important on certain waters. B.
numerosus is known as the dark grannom, while B. appalachia is known as the apple
caddis or grannom. Identification to species would require close inspection of the
abdomen under high magnification. The apple caddis is known to occur in both light
and dark varieties (see photos above), with the light variety sporting a light green
abdomen and light tannish wings, while the dark variety is a dark brown with medium
grey-brown wings. This difference in coloration is related to time since emergence, with
newly hatched individuals being lightest.
Life Cycle & Emergence 3
While other species of Brachycentrus may hatch later into the summer or have
extended hatches (most notably B. americanus), both B. numerosus and B. appalachia
are known to be late spring/early summer hatches which occur over the course of only a
few weeks. Both the emergence and egg-laying habits of Brachycentrus render them a
valuable food source for trout: pupae emerge in the surface film, sometimes struggling
for a length of time to free themselves of the pupal shuck, while adult females land and
ride on the water’s surface to deposit their eggs, once again creating an easy food
source for fish.
Massachusetts: May into and through June, depending on weather and water
temperatures.
Degree of difficulty 3
This table is meant to help users get an idea of how easy/hard it is to ID this species to any taxonomic level, and to give an idea of the characters (or features) that are important to accurately identifying a specimen. As a general guideline, these degree of difficulty levels translate to the type of effort needed to reliably ID a specimen to that taxonomic level, as long as the associated features are confirmed. Of coarse there will/may be exceptions to these general rules.
Brachycentrus sp.
Taxonmoic level
Taxonomic Name
Feature
Degree of difficulty
Order
Trichoptera
Wing Shape
1.5
Family
Brachycentridae
mouthparts under the scope/adults spikes on legs and warts on back
5
Genus
Brachycentrus
mouthparts/legs etc.. under the scope
5
Species
sp.
Many species
NA
Degree of Difficulty
Degree of Difficulty
Description
1
Can be ID’d on the wing or water.
2
A specimen in the hand can be ID’d.
3
Can be ID’d by studying a decent photo of the specimen.
4
Can be ID’d by studying a captured & preserved specimen, usually under some magnification.
5
Proper ID requires study of preserved specimen under magnification, usually looking for some feature that can be difficult to confirm. Usually requires training or confirmation from a professional.
Sources and Credits
- (c) jwsinton, some rights reserved (CC BY-NC), uploaded by jwsinton
- (c) gailhampshire, some rights reserved (CC BY), http://www.flickr.com/photos/gails_pictures/6266228785/
- (c) Jay Aylward, some rights reserved (CC BY-SA)
