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Macroinvertebrates home

Streams project


East Orange Branch (CTWW_ EOBrnch_1567)

These are the most common macroinvertebrates identified from samples from East Orange Branch by East Orange Road in Orange, Vermont.

Click on images to zoom in. 

ORDER: Ephemeroptera
FAMILY: Baetidae 
GENUS: Baetis 

This mayfly has three "tails" and a unique head shape. Its gills are oval shaped and insert dorsally. More mature nymphs have long, dark wing pads. SMC

ORDER: Diptera
FAMILY: Simuliidae

Simuliidae appear  rather like bowling pins with heads.  We have not identified them past family at this point, but it is in the long-term plan.

Aquatic Bioassessment Laboratory, California Digital Reference Collection

ORDER: Trichoptera
FAMILY: Glossomatidae

Larvae in this family build domed cases made of small rocks, and are often wider at segment 5. The pronotum is covered in dark, sclerotized plates, but there are either no sclerites on the mesonotum, or the mesonotum is unsclerotized with the exception of a few patches. The anal proleg is broadly joined to segment 9; the anal claw has one or more accessory hooks. The  pronotal excision is small (approximately 1/3 anterolaterally) to accommodate the coxae.

Commonly encountered genera include Glossosoma and Agapetus.

ORDER: Ephemeroptera
ILY: Heptageniidae

This is the only Heptageniidae genus present in this area with two tails!

ORDER: Trichoptera
FAMILY: Hydropsychidae

This family of net-spinning caddisflies is very abundant at several sites.  They are important filtering collectors and are quite common at urban and agricultural sites where particles of organic material can be important food resources.  Genus-level identification is possible for mature specimens and we will include the genera we found at your site if possible. Commonly found genera include Cheumatopsyche, Ceratopsyche, and Hydropsyche. Less commonly, we have found Arctopsyche and Potamyia.

When using the key, some features that are challenging to see are the forked trochantin and the paired sclerites in the folds between segments.  Other, more easily seen key features include filamentous gills on the abdominal segments and the sclerotization of the dorsal surfaces of all three thoracic segments. Keep in mind that with smaller or more immature specimens, genus-level ID may not be possible.

ORDER: Diptera
FAMILY: Chironomidae

 Midge larvae tend to be the most common macroinvertebrate at our sites.  As with other Diptera, there are no true jointed legs.  Chironomidae do have a pair of prolegs at each end and preserved individuals tend to curl into a 'C'.  Identification past family requires slide-mounted heads.  We have seen philopotamid caddisflies misidentified with the chironomids and we suspect that that happens when samples are being sorted from trays.  Under a microscope, six prominent legs can be seen on members of the family Philopotamidae.

ORDER: Plecoptera
FAMILY: Perlodidae

Stoneflies in the Perlodidae family do not have branching gills from leg bases. When observing their mouthparts, the glossae and paraglossae form a large three-pronged notch, or opening. Hind wing pads are divergent. Cerci, or "tails," are as long or longer than the abdomen.

ORDER: Diptera
FAMILY: Athericidae

Members of the family Athericidae have wrinkled bodies with prolegs on the ventral side. Their mandibles- which can be seen by carefully cutting the head open- move parallel to each other. On the end of their abdomen there are two lobes fringed with setae.

ORDER: Plecoptera
FAMILY: Chloroperlidae
GENUS: Sweltsa

Chloroperlidae have bodies roughly as wide as their pronotum. Their mouthparts look like this, with their paraglossae are much longer than their glossae and a deep notch in the labium. The genus Sweltsa is characterized by having dark clothing hairs at the base of the coxae.

ORDER: Plecoptera
FAMILY: Peltoperlidae

Peltoperlidae have stout, roach-like bodies and can have conical gills at the base of legs. Ventral overlapping plates are found on their large thorax. They have a single gill posterior to thoracic segment 3.  Peltoperlidae is not covered in the family-level key (Bouchard 2006) used by the Streams Project.

ORDER: Ephemeroptera
FAMILY: Ephemerellidae

The mayfly Ephemerellidae is distinguished by the absence of gills on the second abdominal segment; individuals either have gills on segments 3-7 or 4-7. Some may have operculate (plate-like) gills on the fourth segment, though in many the gills are of identical size.

Commonly encountered genera include Drunella, Ephemerella, and Serratella.


ORDER: Trichoptera
FAMILY: Philopotamidae
GENUS: Dolophilodes

Dolophilodes stands out in the Philopotamidae family due to its slightly asymmetrical frontoclypeus on the anterior margin and its distinguishable projecting foretrochantin.

ORDER: Ephemeroptera
FAMILY: Heptageniidae
Genus: Maccaffertium

This genus of Heptageniidae is distinguished by its gills on the seventh abdominal segment, which are reduced to slender filaments. Gills on segments 1-6 are truncated.


ORDER: Plecoptera
FAMILY: Pteronarcyidae
GENUS: Pteronarcys

Pteronarcyidae have branching gills from the bases of their legs as does Perlidae. What distinguishes Pteronarcyidae from Perlidae is the presence of gills on the first two abdominal segments. There are only two genera in this family, but the other, Pteronarcella, is only found in the west/southwest.

ORDER: Coleoptera

We have found adult and larval riffle beetles. The adults are clearly beetles, but the larvae can be confused with other orders. The forward pointing tooth on the front end of the larvae as described in the key can be a challenge to see, particularly in small individuals.

Larvae are characterized by having a single tarsal claw at the end of their legs, which have 4 segments. Adults, on the other hand, have two tarsal claws at the end of each leg.

Commonly encountered genera include Dubiraphia, Macronychus, Optioservus, Phanocerus, Promoresia, and Stenelmis.

The images are not a substitute for keying, but should serve as an aid in identifying common macroinvertebrates in samples.

Feedback - Partner schools: send us specimens not included above.  Taxonomists: click to email: Declan McCabe
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