Lamoille River

ORDER: Ephemeroptera
FAMILY: Baetidae 
GENUS: Baetis 

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

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.  Chironomids 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 the philopotamids.

ORDER: Diptera
FAMILY: Simuliidae

What's not to like about blackflies?  Our second most common dipteran.  Rather like a bowling pin with hands attached at the head end.  We have not identified them past family at this point, but it is in the long-term plan.
NABS

ORDER: Plecoptera
FAMILY: Perlidae
GENUS: Hansonoperla

This stonefly is characterized by the filamentous gills located in the "armpit". Another important feature is the paraglossae and glossae extending different lengths. The occiput lacks a row of spinules and there are a few setae behind the eyes.

PHYLUM: Annelida
CLASS: Oligochaeta

Aquatic earthworms lack legs and are characterized by having 20 or more segments. Unlike leeches, they lack a suction disk.

© Aquatic Bioassessment Laboratory, California Digital Reference Collection

ORDER: Trichoptera
FAMILY: Glossomatidae
GENUS: Glossosoma

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 no sclerites on the mesonotum. 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.

ORDER: Trichoptera
FAMILY: Rhyacophilidae
GENUS: Rhyacophila

Rhyacophila is a common caddisfly in Otter Creek. In our lab it is known as the "Michelin Man" due to its large white banded body. It has a very obviously checker-patterned head. It also has a terrifying anal claw which has large accessory hooks. SMC

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: Plecoptera
FAMILY: Perlidae
GENUS: Agnetina

The Agnetina has a rounded abdomen that appears to striped. The key defining characteristic is the three ocelli on the dorsum of the head (3 black dots at joint with the prosternum). Like other Plecoptera, it has 2 tails and 2 claws on its tarsi. SMC

This stonefly is characterized by the filamentous gills located in the "armpit". Another important feature is the paraglossae and glossae extending different lengths. The occiput has a transverse row of little hairs evenly spaced. Agnetina has another row of hair on abdominal segment 7 which is spaced evenly across the whole segment.

ORDER: Ephemeroptera
FAMILY: Heptageniidae

This family of mayflies can be characterized by their distinctly flattened heads and striking resemblance of the character 'Jack Skellington' from the movie 'The Nightmare Before Christmas.' This family can either have two or three tails.

ORDER: Ephemeroptera
FAMILY: Ephemerellidae
GENUS: Drunella

The mayfly Drunella is distinguished by its large femoral “biceps” on the front legs. The body rests in one plane with the biceps at the same level as the head and junction with the thorax.

© US EPA

ORDER: Diptera
FAMILY: Tipulidae
GENUS: Hexatoma

These tipulids can be identified by their swollen 7th abdominal segment.

ORDER: Diptera
FAMILY: Tipulidae
GENUS: Antocha

This small dipteran in the cranefly family is quite common.  It is distinguished from most other dipterans we found by the 'creeping welts' that appear as prominent dark stripes along the abdomen.  The dark head is usually partly exposed; however, it can be pulled back into the thoracic cavity during preservation.
NABS

ORDER: Coleoptera 
FAMILY: Elmidae
GENUS: Optioservus

The larvae of Optopservus have a closed coxae, as determined by the straight definition between segments on the ventral side of the pronotum.

The adult Optioservus have a compact appearance, especially the head and thorax. There are also dorsal ridges and a characteristic diamond-shaped feature observable in the dorsal view. SMC

ORDER: Plecoptera
FAMILY: Leuctridae
GENUS: Leuctra

Among our most common stoneflies, this family is fairly slender by stonefly standards.  The divergent wing pads are a helpful characteristic. Leuctridae  are similar in overall shape to the Capniidae; however, Leuctridae often do not have pleural folds. If they are present, they only extend from abdominal segments 1-7.  Leuctra  are recognized by abdominal terga with posterior fringes of short hairs and last few segments with longer hairs. NABS

ORDER: Megaloptera
FAMILY: Corydalidae
GENUS: Nigronia

Members of the genus Nigronia share some superficial commonalities with Trichoptera, but on careful inspection one can see the two pairs of anal claws that help place it in the order Megaloptera.  The size of mature larvae is impressive; specimens from other genera exceed 8 cm in length.  The abdominal segments have ribbon-like gills on the lateral portions. The mouth has mandibles that are serrated and used for biting prey.  They can be confused with the more slender whirligig beetle larvae; whirligig larvae also have simpler jaws.   SMC