Malletts Creek

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Streams logo web.jpg Malletts Creek
Stream code:LCD_MllttsCrk_616
Basin:Lake Champlain
State or Province:Vermont
Country:USA
Latitude:44.63559
Longitude:-73.086612
School:Milton High School


The following are the most common invertebrates collected from this stream site.

Chironomidae

Chironomidae.jpg
Order
Diptera
Family
Chironomidae


Common name
Nonbiting midge
Tied fly
Griffith's Gnat
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 caddisfly family Philopotamidae.

More information on Philopotamidae.




Hydropsychidae

Hydropsyche.jpg
Order
Trichoptera (caddisfly)
Family
Hydropsychidae


Common name
net spinning caddisfly
Tied fly
Emergent Sparkle Pupa, Vermont Hare's Ear
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.

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.

Commonly found genera include Cheumatopsyche, Ceratopsyche, and Hydropsyche. Less commonly, we have found Arctopsyche and Potamyia.

Images of the forked trochantin and the paired sclerites.




Optioservus

Optioservus (Larvae).jpg
Order
Coleoptera
Family
Elmidae
Genus
Optioservus


The larvae of Optioservus have open 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 sutellum observable in the dorsal view.

Images of the straight definition between segments, the dorsal ridgesand the diamond-shaped scutellum.




Stenelmis

Stenelmis (larvae).jpg
Order
Coleoptera
Family
Elmidae
Genus
Stenelmis


The larvae of Stenelmis, as in Ordobrevia, have a sternum on the ventral side of the pronotum. The main difference between the two genera is in the antennae the second segment is less than twice as long as the first in Stenelmis.

The adult Stenelmis has a clear separation between the thorax and abdomen as well as a more distinctly separate head as compared to other genera.

Click here to see pictures of the sternum and antennae-




Psephenus

Psephenus.jpg
Order
Coleoptera
Family
Psephenidae
Genus
Psephenus


The true "water penny" is commonly found in the waters sampled. Psephenus has a rounded shape with relatively smooth edge. The false water penny, whose edges are serrated, has a more oval appearance. The gills on the ventral surface are found only in the true water pennies.

Another genus encountered in this family is Ectopria.



Athericidae

Athericidae.jpg
Order
Diptera
Family
Athericidae


Common name
water snipe flies
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. Our collections include just the single genus Atherix.

Image of the two lobes of the abdomen.



Ceratopogonidae

Ceratopogonidae.jpg
Order
Diptera
Family
Ceratopogonidae


Common name
biting midges
Members of this family look like very straight Chironomidae. They are very long and thin with a distinct head capsule and no prolegs. Some in the lab call them 'bamboo sticks' with eyes.

Image of the distinct head capsule.




Glossosomatidae

Glossosoma - Whole3.jpg
Order
Trichoptera
Family
Glossosomatidae


Common name
saddlecase caddisfly
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.




Simuliidae

Simuliidae.jpg
Order
Diptera
Family
Simuliidae


Simuliidae appear rather like bowling pins with heads. Relatively speaking, we collect few members of this family and have we have not identified them past family at this point.

Click here for a close up image of the heads.




Dicranota

Dicranota cover.jpg
Order
Diptera
Family
Tipulidae
Genus
dicranota


Dicranota can be distinguished by the two tails and their comb feet. There are usually 5 pairs of prolegs on the abdomen with combs on them. In addition, the posterior portion of the abdomen often has a slight swelling.

Image of the prolegs.




Tipula

Tipula cover.jpg
Order
Diptera
Family
Tipulidae
Genus
Tipula


This genus of Tipula is rather large as compared with other genera. Tipula larvae are generally dark brown and have creeping welts.




Baetis

Baetis.jpg
Order
Ephemeroptera
Family
Baetidae
Genus
Baetis


Common name
The Little Olive
Tied fly
Sawyer Pheasant Tail Nymph
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.

Image of the long, dark wing pads.




Chimarra

Chimarra.jpg
Order
Trichoptera
Family
Philopotamidae
Genus
Chimarra


Chimarra are distinguished from the other Philopotamidae by a prominent asymmetrical notch in the frontoclypeus as well as a prominent process on the femur which bears a single hair (seta).

Images of the asymmetrical notch and prominent process.



Dolophilodes

Dolophilodes.jpg
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.

Images of the slightly asymmetrical frontoclypeus, and the projecting foretrochantin.




Pseudocloeon

Pseudocleon whole side.jpg
Order
Ephemeroptera
Family
Baetidae
Genus
Pseudocloeon


Tied fly
Bluewinged Olive
Mayflies in this genus have a distal lobe on their antennal scapes, and the second segment of labial palps has an expanded medial process. Villopores are absent on legs.

Click to see the antennal scapes. The dorsal and ventral views can be seen here.




Epeorus

Epeorus.jpg
Order
Ephemeroptera
Family
Heptageniidae
Genus
Epeorus


Common name
The Quill Gordon
Tied fly
Quill Gordon
This is the only Heptageniidae genus present in this area with two tails!




Leptophlebiidae

Leptophlebiidae whole.jpg
Order
Ephemeroptera
Family
Leptophlebiidae


Common name
pronggill mayfly
Leptophlebiidae are characterized by a somewhat flattened body and forked elongate gills. Commonly found genera include Habrophlebia and Paraleptophlebia.

Image of the forked elongate gills.




Siphlonuridae

Siphlonuridae.jpg
Order
Ephemeroptera
Family
Siphlonuridae
Genus
Siphlonurus


Common name
The Gray Drake
Tied fly
Gold-ribbed Hare's Ear
This family has gills on all abdominal segments. The labrum does not have a deep notch, and maxillae do not have pectinate spines. They have posterolateral spines on their last abdominal segment.

Click to view the spines on the last abdominal segment, unlike those found in Baetidae.




Chloroperlidae

Chloroperlidae.jpg
Order
Plecoptera
Family
Chloroperlidae


Common name
The Yellow Sally
Tied fly
Yellow Sally
Stoneflies from the family Chloroperlidae have cylindrical banded abdomens. When observing their mouthparts, the glossae and paraglossae form a three-pronged (open) notch, and their hind wing pads are parallel (not divergent). Cerci have a vertical fringe of hairs pointing away from the abdomen. Setae on the pronotum are found primarily at the corners.




Leuctra

Leuctra2.jpg
Order
Plecoptera
Family
Leuctridae
Genus
Leuctra


This family of stonefly 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.

Image of the divergent wing pads.




Paragnetina

Paragnetina.jpg
Order
Plecoptera
Family
Perlidae
Genus
Paragnetina


Paragnetina have 3 ocelli (spots) on the back of their head. Like the other Perlidae, there are highly branched gills located on the sides of the thorax. The dorsal sides of the abdominal segments have small hairs on lateral portions but not in the center of the segment.