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Glossary for the Trichoptera of Gunnison County, Colorado

Updated 1 May 2013
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  • abdomen - The segmented back end of an insect. The abdomen may have gills in caddis larvae, but will not have legs. The abdomen has one set of anal prolegs with a sturdy anal claw on the last segment of the abdomen. Small sclerites et the end of the abdomen or on the anal prolegs are sometimes used to identify larvae. If the segments you're looking at have legs or wings, you're admiring the thorax of a caddis.

  • Annulipalpia - A suborder of caddisflies containing the fixed retreat makers and net spinning caddisflies. Adults have a flexible ringed terminal segment of the maxillary palps. Families in the Gunnison Basin include: Hydropsychidae, Philopotamidae, and Psychomyiidae. Also called Hydropsychoidea.

  • antennae - The first pair of appendages on a caddisflies head. Larvae have very small antennae so they are inconspicuous unless you are looking at a Leptoceridae larvae. Antennae location is important when identifying the larvae of the caddis family Lepidostomatidae. Adults have long filiform antennae (see the photo).

  • anterior - Indicates towards the head of an animal. Anterior may indicate a structure in front of (towards the head or front of the animal) another structure on a caddis. See posterior.

  • apneustic - a tracheal system with no open spiracles, caddis larvae are apneustic.

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  • chitin - a nitrogen-containing polysaccharide that forms a rigid plate called a sclerite.

  • chloride epithelia - Oval structures on the abdomen of caddis larvae that are used by the larvae for osmoregulation and by humans for identification of genera. They are often faint and hard to see.

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  • dorsal - Indicates the back of an animal.

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  • ecdysis - Molting, when the insect sheds it's external exoskeleton to allow growth to the next instar.

  • electroantennogram - tests whether antennae react to a substance. Often used studying phermones.

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  • fenestra - area of transparent cuticle, sometimes surrounded by a darker marking. Often present in pairs.

  • fuscous - dark brown, almost black
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  • guttae - small spots or dots
  • guttated - marked with small spots or dots
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  • Holometabola or Holometabolous - Caddisflies undergo complete development or complete metamorphosis, which means they go through 4 life stages; egg, larva, pupae and adult. As a result of time spent as a pupae, the insect can completely reorganize it's internal and external organs. Therefore the adults look very different from the larvae. Contrast this with the development of stoneflies or mayflies which undergo hemimetabolous development, skipping the pupal stage.

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  • instar - Caddis larvae molt through 5 instars. Every time they shed their exoskeleton, the larvae grow larger and are considered to be in the next instar. Each instar is usually logarithmically larger in mass than the last instar. Experienced field biologists may be able to estimate caddis larvae instars while the animals are alive in the field. With each instar, the larvae may gain gills, setae or other traits which is why you need an older or later instar larvae for identification purposes.

  • Integripalpia - Portable case makers. Adults have an unringed terminal segment of the maxillary palp. Gunnison Basin families include: Leptoceridae, Molannidae, Apataniidae, Brachycentridae, Lepidostomatidae, Limnephilidae, Uenoidae and Phryganeidae.

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  • labrum - Somewhat similar to the upper lip of a mammal, it is located below the cylpeus on the anterior or front of the head.

  • luteous - egg-yellow or clay yellow (Hagen 1861)
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  • multivoltine - a life cycle that allows several generations per year. There will be more than one adult flight period per year.

  • muscle scar - a dark or light ovoid scar on a sclerite. Caddis use them to attach their muscles, humans use them for identification.

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  • ochre - yellow-orange, tan
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  • pile - small hairs, sometimes in rows (Hagen 1861)
  • pilose - clothed with small hairs, often in rows (Hagen 1861)
  • phylogenetics - the study of evolutionary relationships between species using morphology or DNA.

  • posterior - indicates towards the back of an animal, away from the head. Posterior may be used to indicate a structure behind another structure. The opposite of anterior.

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  • sclerite - a chitinous or hard plate on an insect, bounded by sutures or lines of division. For example, in caddis larvae the head is always completely sclerotized, while the thorax may have a variety of different sclerites depending on the species of animal under consideration. Frequently used for identification purposes.

  • sensu stricto or stricto sensu - Taxonomists use these latin phrases to indicate "in the stricter sense", abbreviated s.s. Stricto sensu is often used when discussing a subgenera with the same name as the genus under consideration. This may apply to other taxonmic levels such as families or species.

  • setae - a bristle or hair-like structures on insects. Used by humans for identification.

  • Spicipalpia - A suborder of caddisflies called the closed-cocoon makers. This refers to their practice of weaving a case for pupation at the end of their last larval instar. Adults have pointed maxillary palps. Includes the families Glossosomatidae (stone, turtle-like case), Hydroptilidae (woven purse-like case) and Rhyacophilidae (free living). DNA evidence may eliminate this suborder.

  • synapomorphy - A shared trait between taxa and their common ancestor. But the next ancestor back does not share the trait. This allows scientists to group species by probable relatedness. Sometimes a species will secondarily lose a trait even though most of it's sibling species have it. Synapomorphy is a term used when discussing phylogenetics. For example, Lepidoptera and Trichoptera have a syapomorphy of glands on the 5th sternum.

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  • thorax - the part of an insect body between the head and abdomen. In caddis larvae, the thorax has legs attached, adult caddis have legs and wings attached to the thorax.

  • TSN - Taxonomic Serial Number, a unique number for each species, genera, and all taxnomic levels created by Integrated Taxonomic Information System for use in databases.

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  • univoltine - an insect life cycle that has one generation per year.

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  • ventral - indicates the underside. Humans think of it as the belly side of an animal.

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    Hagen,HA 1861 Synopsis of the Neuroptera of North America with a list of South American species. Smithsonian Miscellaneous Collections 4, glossary on pages 340-344.

    Brown, Wendy S. 2009 Key to the Trichoptera of Gunnison County, Colorado