late long-horned caddisfly

(Triaenodes tardus)

Conservation Status
late long-horned caddisfly
Photo by Alfredo Colon
  IUCN Red List

not listed


N4N5 - Apparently Secure to Secure

SNR - Unranked


not listed


Late long-horned caddisfly is common small caddisfly. It occurs in North America mostly in the east and in the Pacific Northwest. In the United States it occurs from Maine and North Dakota south to Ohio and Kansas, and from Washington to northern California, with scattered records in between and in the south. It is common in Minnesota, where it is the second most widespread caddisfly species. Global Biodiversity Information Facility (GBIF) shows more records from Minnesota by far than from any other U.S. state or Canadian province. Larvae eat living plant material. They are found in the beds of submerged aquatic plants, both in the still water of wetlands and along the shores of lakes and ponds, and in the fast moving water of rivers and streams. Adults do not feed. They are usually found near the aquatic habitat of the larvae, but may wander up to several miles. They are active at night (nocturnal) and at dusk and dawn (crepuscular). They are attracted to light.

Adults are slender and 516 to ½ (8 to 12 mm) in length.

There are two compound eyes but no simple eyes (ocelli). The antennae are pale, thread-like, and long, more than twice as long as the forewings. On the first quarter of each antenna there is a dark brown band at the base of each segment. The mouth parts are reduced but the finger-like sensory organs attached to the mouth (maxillary palps) are well developed. On both sexes they have 5 segments. The last segment is not much longer than the other segments and does not have horizontal grooves.

The thorax has three exoskeletal plates above. The plate covering the first segment (pronotum) has a pair of warts separated be a deep notch. The plate covering the second segment (mesoscutum) has two irregular rows of closely spaced bristly spots.

There are 4 membranous wings. The hindwings are a little shorter than the forewings. The forewings are light brown with dark brown markings on the outer third. When the wings are at rest they are held roof-like over the body and the dark brown areas of each wing meet in the middle. No hairs on the forewings have an enlarged or swollen tip (clubbed). The median vein (M) has 4 branches on the forewing, 3 branches on the hindwing. The cubitus vein (Cu) on each wing has 3 branches. There is a small spot on each wing in the fork of the fourth and fifth branch of the radius vein (R4+5).

The legs are relatively long and slender. The fourth segment (tibia) of the middle leg does not have a row of spurs near the tip but does have a row of black spines. The last part of the leg (tarsus), corresponding to the foot, has 5 segments. At the end of each tarsus there is a pair of claws. The claws on the middle and hind legs are equal in length.

The larva is similar in appearance to a caterpillar. It constructs a portable protective tube up to 1516 (33 mm) long in which it lives. The tube is made of plant pieces arranged in a spiral pattern.




Total Length: 516 to ½ (8 to 12 mm)


Similar Species


Lakes, streams, rivers, and wetlands; all habitat types.




One generation per year: May through September




Adults are active at night (nocturnal) and at dusk and dawn (crepuscular). They are attracted to light.


Life Cycle


The female lays a flat oval mass of eggs.


Larva Food


Plant fragments


Adult Food




Distribution Map



24, 27, 29, 30, 82, 83.




Common and widespread in Minnesota



Trichoptera (caddisflies)  








Leptoceridae (long-horned caddisflies)  









Triaenodes marginata tarda

Triaenodes mephitus

Triaenodes tarda


Common Names


late long-horned caddisfly









Paired mouth structures of arthropods located immediately behind the mandible and used for tasting and manipulating food. “Under-jaws”.



Simple eye; an eye with a single lens. Plural: ocelli.



Short for pedipalp. A segmented, finger-like process of an arthropod; one is attached to each maxilla and two are attached to the labium. They function as sense organs in spiders and insects, and as weapons in scorpions. Plural: palpi or palps.



The saddle-shaped, exoskeletal plate on the upper side of the first segment of the thorax of an insect.



On insects, the last two to five subdivisions of the leg, attached to the tibia; the foot. On spiders, the last segment of the leg. Plural: tarsi.



The fourth segment of an insect leg, after the femur and before the tarsus (foot). The fifth segment of a spider leg or palp.






Visitor Photos

Share your photo of this insect.

  This button not working for you?
Simply email us at
Attach one or more photos and, if you like, a caption.

Alfredo Colon

    late long-horned caddisfly      








Visitor Videos

Share your video of this insect.

  This button not working for you?
Simply email us at
Attach a video, a YouTube link, or a cloud storage link.


Other Videos



Visitor Sightings

Report a sighting of this insect.

  This button not working for you?
Simply email us at
Be sure to include a location.
  Alfredo Colon

Location: Woodbury, MN

late long-horned caddisfly  






Created: 12/1/2020

Last Updated:

About Us | Privacy Policy | Contact Us | © All rights reserved.