Taxonomic Atlas of the Caddisfly Larvae
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Taxonomic Atlas of the Caddisfly Larvae (Class Insecta: Order Trichoptera) Recorded at the Old Woman Creek National Estuarine Research Reserve and State Nature Preserve, Ohio by Tamara S. Keller and Kenneth A. Krieger National Center for Water Quality Research Heidelberg University Tiffin, Ohio, USA 44883 March 2009 Atlas of the Caddisfly Larvae (Class Insecta: Order Trichoptera) Recorded at the Old Woman Creek National Estuarine Research Reserve and State Nature Preserve, Ohio Acknowledgments The authors are grateful for the assistance of Dr. David Klarer, Old Woman Creek National Estuarine Research Reserve, for providing funding for this project and for his critical reviews of drafts. This work was funded under contract to Heidelberg University by the Ohio Department of Natural Resources. This publication was supported in part by Grant Number H50/CCH524266 from the Centers for Disease Control and Prevention. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of Centers for Disease Control and Prevention. The Old Woman Creek National Estuarine Research Reserve in Ohio is part of the National Estuarine Research Reserve System (NERRS), established by Section 315 of the Coastal Zone Management Act, as amended. Additional information about the system can be obtained from the Estuarine Reserves Division, Office of Ocean and Coastal Resource Management, National Oceanic and Atmospheric Administration, U.S. Department of Commerce, 1305 East West Highway – N/ORM5, Silver Spring, MD 20910. Financial support for this publication was provided by a grant under the Federal Coastal Zone Management Act, administered by the Office of Ocean and Coastal Resource Management, National Oceanic and Atmospheric Administration, Silver Spring, MD. Copies of this publication are available from the Ohio Department of Natural Resources - Division of Wildlife 2514 Cleveland Road East Huron, Ohio 44839 This publication can be downloaded at www.heidelberg.edu/wql/educationoutreach Introduction Both the formal biologist and the amateur naturalist often encounter lists of animals and plants when they read published scientific reports and visit nature centers. Rarely do they have ready access to photographs for each member of the list. Ceraclea sp. larva in case This document constitutes one of several chapters of a comprehensive atlas of the rivers and wetlands. Foods of larval biota of the Old Woman Creek coastal caddisflies vary from algae and coarse wetland system (OWC) along Lake Erie plant particles to other invertebrates. in Ohio. This chapter provides a detailed The larvae themselves serve as an pictorial record of the aquatic larvae of a important food source for a variety of group of insects, the caddisflies (Order fish. Trichoptera). Caddisfly larvae are well known for their Invertebrates occur in great abundance construction of cases, nets and retreats. in freshwater ecosystems, including The design and composition of the cases Great Lakes wetlands such as the and retreats is dependent on the marshes and swamps that make up ecological niche of each species. OWC. A few of those invertebrates, such Trichoptera families are usually as freshwater mussels, grass shrimps, categorized according to which type of and giant water bugs, are readily visible retreat they build. Cases and retreats because of their large size. Many are composed of silk which the larva freshwater invertebrates, however, are emits from a specialized mouthpart (the so small that special attention must be labium) and often incorporate sand, given to collecting – and seeing – them. vegetation, and rock fragments. Thus, most groups of invertebrates go unnoticed by casual visitors to aquatic Characteristics of Larval habitats. Larval caddisflies of the Order Trichoptera Trichoptera are no exception. Furthermore, once collected, the ability As members of the insect Order to distinguish one kind of caddisfly from Trichoptera, caddisflies have four life another requires careful observation stages: egg, larva, pupa, and adult. In through a dissecting microscope. most families, the female deposits eggs in or above water, and the eggs of Family This atlas presents detailed photographs Polycentropodidae can actually survive of critical diagnostic features that permit dry conditions. The larva of most the correct identification of most caddisfly caddisfly families undergoes five stages, larvae found to date at OWC to the or instars, before fastening its case to a taxonomic level of genus. solid substrate when entering the pupal stage. Generally, the pupa emerges as Caddisflies are found in a wide variety of an adult after two or three weeks. freshwater habitats, especially creeks, Mtt General features of a caddisfly larva are Mtn Mst shown in the photographs on this page. Msn The body is divided into three regions: head (H), thorax (T), and abdomen (A). Pt Head structures include a labrum (L) and G a submentum (S). Mouthparts used in Pn Sc identification are the mandibles (M) and the maxillary palpi (MP). AC The three thoracic segments are the Lateral view of Hydropsyche sp. prothorax (Pt), mesothorax (Mst), and metathorax (Mtt). The dorsal surfaces of the thoracic segments are called the pronotum (Pn), mesonotum (Msn), and metanotum (Mtn) and often possess hardened plates known as sclerites (Sc). The ventral surfaces of the thorax are the Tr Hydropsyche sp. prosternum (Ps), mesosternum (Mss), trochantin and metasternum (Mts). Club hairs (CH) L and scale hairs (SH) are present on the thorax and abdomen of some genera. M Tr CC MP The abdomen usually features gills (G) Oecetis sp. head and always terminates in two prolegs (P), F each with an anal claw (AC). The legs Ti consist of five parts: the coxa (C) and TCTa trochanter (Tr), closest to the body, and the femur (F), tibia (Ti), and tarsus (Ta). A S Hydropsyche sp. H tarsal claw (TC) is present at the end of middle leg each tarsus. A sclerotized appendage CH called a trochantin (Tr) is present at the base of the foreleg of some caddisflies. Ps Mss T Layout of this Atlas Ceratopsyche sp. Mts The following pages are organized Lateral view alphabetically by family. Collectors have identified twenty-two genera of caddisflies SH in seven families (Hydropsychidae, P A Hydroptilidae, Leptoceridae, Limnephilidae, Philopotamidae, Phryganeidae, and Polycentropodidae) within the OWC wetland system, which excludes the Hydropsyche sp. Chimarra sp. ventral view, Lateral view showing recurved abdomen free-flowing upland reaches of Old Woman All taxonomic information on each page Creek. Specimens in all seven families was derived from three or more and fifteen genera were available for references, which are abbreviated as inclusion in this atlas. shown below followed by the page number(s): This publication should not be used as the sole source to identify the genera of larval H = Hilsenhoff, W.L. 1995. Aquatic trichopterans of OWC because it is likely Insects of Wisconsin, keys to Wisconsin that additional families and genera will be genera and notes on biology, habitat, found in new collections. The references distribution and species. Publication No. cited on this page should be used to obtain 3 of the Natural History Museums definitive identifications. The species Council, Univ. of Wisconsin-Madison. within each genus are not included here, Cooperative Extension Publications, and the species of some genera cannot be Madison, Wisconsin. identified in the larval stages. M&H = Morse, John C. and Ralph W. Each genus of caddisfly larva is illustrated Holzenthal. 1996. Trichoptera Genera. and described on a single page of this In Merritt, R.W., and K.W. Cummins atlas. Because the identifying features of (Eds.). An Introduction to the Aquatic the Order Trichoptera and the particular Insects of North America. 3rd Ed. family are repeated on each page, the Kendall/Hunt Publ. Co., Dubuque, Iowa. page for each genus can be used independently. Photographs are labeled V = Voshell, Jr., J. Reese. 2002. A with identifying letters and lines or brackets Guide to Common Freshwater that indicate diagnostic structures. Some Invertebrates of North America. The photographs show specimens collected McDonald and Woodward Publishing within OWC; specimens from other Co., Blacksburg, Virginia. ecosystems were used if they were of superior quality. The exact specimens W = Wiggins, Glenn B. 1996. photographed are recorded at the bottom Trichoptera Families. In Merritt, R.W., of the page. and K.W. Cummins (Eds.). An Introduction to the Aquatic Insects of Beneath the descriptive features, each North America. 3rd Ed. Kendall/Hunt page lists where within OWC the genus Publ. Co., Dubuque, Iowa. has been found. That information was derived from reports compiled by Herdendorf et al. (2001)*. It is likely that future collections will reveal some of the genera in additional habitats. The general ecology of the genus is briefly summarized, * Herdendorf, C.E., R.C. Herdendorf, and D.M. including its habit (such as sprawler or Klarer. 2001. Catalogue of the invertebrate fauna climber) and its functional feeding group of Old Woman Creek estuary, watershed, and adjacent waters of Lake Erie. Technical Report (such as predator), and for some genera, No. 12. Old Woman Creek National Estuarine special notes about its habitat or water Research Reserve & State Nature Preserve, quality requirements. Huron, Ohio. Checklist of Genera of Caddisfly (Trichoptera) Larvae Reported in the OWC Wetland System Specimens reported as collected at OWC