D. L. DEONU A Systematic and Ecological Study of Nearctic Hydrellia Diptera: Ephydridae) SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY NUMBER 68 SERIAL PUBLICATIONS OF THE SMITHSONIAN INSTITUTION The emphasis upon publications as a means of diffusing knowledge was expressed by the first Secretary of the Smithsonian Institution. In his formal plan for the Insti- tution, Joseph Henry articulated a program that included the following statement: "It is proposed to publish a series of reports, giving an account of the new discoveries in science, and of the changes made from year to year in all branches of knowledge not strictly professional." 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Each publica- tion is distributed by mailing lists to libraries, laboratories, institutes, and interested specialists throughout the world. Individual copies may be obtained from the Smith- sonian Institution Press as long as stocks are available. S. DILLON RIPLEY Secretary Smithsonian Institution SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY NUMBER 68 A Systematic and Ecological Study of Nearctic Hydrellia (Diptera: Ephydridae) SMITHSONIAN INSTITUTION PRESS CITY OF WASHINGTON 1971 ABSTRACT Deonier, D. L. A Systematic and Ecological Study of Nearctic Hydrellia (Diptera: Ephydridae). Smithsonian Contributions to Zoology, 68:1-147. 1971.—The adults of 57 species of Hydrellia are described for the Nearctic Region. Adults of Hydrellia are semiaquatic and the larvae are leafminers in aquatic and semiaquatic plants. Twenty-one of the described species are new, and one represents a new geographic distribution record. Some or all of the immature instars of 18 species are described. The male terminalia and certain other critical characters are figured for the adults of 52 species. The larval feeding apparatus of 16 species and the puparia of 17 species are illustrated. Geographic distribution data are given for all species. New and previously recorded host plants are listed for several species, and other biolog- ical information such as habitats and behavior is given for most of the species. The general morphology of the genus, including morphology of the adult feeding appara- tus and gut and internal genitalia, is discussed and illustrated. The general ecology of Hydrellia is discussed in regard to ecological role and distribution, parasitological data, dispersal and zoogeography, behavior, and environmental tolerance. Addi- tional ecological data are included in checklists of known host plants and known hymenopterous parasites of Hydrellia. Literature pertinent to the genus is reviewed. Official publication date is handstamped in a limited number of initial copies and is recorded in the Institution's annual report, Smithsonian Year. UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON : 1971 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington. D.C. 20402 - Price $1.75 (paper cover) Contents Page Introduction 1 Review of Literature 1 Acknowledgments and Repositories 3 Methods and Materials 4 Morphology 6 Glossary 6 External Morphology of Adult 8 Internal Morphology of Adult 13 Morphology of Immatures 15 Ecology 18 Ecological Role and Distribution 18 Parasitological Data 19 Dispersal and Zoogeography 20 Behavior 20 Environmental Tolerance 23 Host Plants and Parasitic Wasps 24 Systematic Treatment 24 Classification 24 Key to Adult Hydrellia 26 Male Terminalia Key to Hydrellia 29 Key to Third-Instar Larvae of some Hydrellia 33 Key to Puparia of some Hydrellia 34 Species Descriptions 36 Checklist of Known Host Plants 106 Checklist of Known Parasitic Wasps 113 Literature Cited 118 Localities of Specimens Illustrated 125 Abbreviations Used on Illustrations 126 Illustrations 128 D. L. Deonier A Systematic and Ecological Study of Nearctic Hydrellia (Diptera: Ephydridae) Introduction available names are valid. These 113 species are dis- tributed as follows: 55 Palaearctic, 35 Nearctic, 1 The Ephydridae constitute a medium-size family Holarctic, 2 Oriental, 12 Australian, 2 Ethiopian, of acalyptrate Diptera. They lead several different and 6 Neotropical. This essentially cosmopolitan modes of life, mostly in aquatic habitats. Hydrellia generic distribution has caused some interest in the and Lemnaphila are the only known genera of dispersal center. Some data possibly indicate this aquatic leaf-mining ephydrids. was in the northern temperate zone. At least two species of Hydrellia—H. griseola and I started this research with the following objec- H. ischiaca—are economically important. In 1953, tives: (1) to describe, redescribe, and construct keys H. griseola destroyed from 10 to 20 percent of Cali- to the adults and as many immature stages as pos- fornia's rice crop, with an estimated loss of $16 sible of Nearctic species; (2) to describe the life million. The same species caused heavy losses of rice cycles and behavior of as many as possible of the in California in 1922. It has damaged rice in Japan Nearctic species; (3) to present a brief morphology in the last two decades. Ulljeborg (1861) first re- of the genus. corded the pest status of H. griseola. He reported the fairly widespread damage of barley, oats, and timothy grass by that species in southern and south- Review of Literature eastern Sweden during the summer of 1860. After this, several authors reported outbreaks of H. griseola The taxonomic literature on Hydrellia dates from in various places in the Palaearctic Region, including 1813, when Fallen described Notiphila griseola and Egypt. Balachowsky and Mesnil (1935) reported several congeneric species from southern Sweden. 50 percent infestation of barley by H. griseola in In 1830, Robineau-Desvoidy erected the new genus northern Europe. Hydrellia ischiaca attacks wild Hydrellia. Macquart (1835), Zetterstedt (1846), rice, which is now a minor crop in Minnesota. Most Walker (1856), Loew (1860), Schiner (1864), of the known larvae of other Hydrellia species feed Brischke (1883), Gobert (1887), Kowarz (1894), mainly in plants of Potamogetonaceae, Alismataceae, and Becker (18%, 1903) made many of the initial and Hydrocharitaceae. contributions to the taxonomy of Palaearctic species. There are 185 available specific names in Hydrellia Strobl (1904), Griinberg (1910), Becker (1919), other than my new species. Of these, perhaps 133 Collin (1928), Frey (1933), de Meijere (1939), have existing holotypes, and perhaps 132 of the 185 Goetghebuer (1942), Grensted (1944), Kloet and have Palaearctic type-localities. Possibly 113 of the Hincks (1945), and Tsacas (1959, 1960) added some descriptions of new species, but primarily they pre- D. L. Deonier, Department of Zoology and Physiology, sented reviews and new distribution records. Dahl Miami University, Oxford, Ohio 45056. (1967) presented a zoogeographical synopsis of 1 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY eleven European species and (1968) described three (1903), Tonnoir and Malloch (1926), Cresson new species along with new records from eastern (1948), and Harrison (1959) published on some or Siberia. Becker's (1896, 1926) synoptic keys to and all of the twelve known indigenous species. The descriptions of Palaearctic adult Hydrellia and Hen- relatively small amount of attention given to Orien- nig's (1943) specific key to larval Hydrellia including tal and Australian Hydrellia is matched only for the Palaearctic species contributed most to the taxonomy Ethiopian Hydrellia. Cresson (1932, 1947b) listed of Palaearctic species of Hydrellia. The recent re- two species, both from the Cape of Good Hope. vision by Dahl (1964) of the Stenhammar and The works of the following authors provide some Zetterstedt collections eliminated much confusion framework for a more searching morphological study and synonymy in Palaearctic Hydrellia. of adult Hydrellia. Becker (1896, 1926), Griinberg Loew (1861, 1862) described the first new species (1910), Cresson (1918), and Wilke (1924) dealt of Nearctic Hydrellia. Loew (1872), Osten Sacken mainly with chaetotaxy, but Cresson did briefly dis- (1878), Becker (1896), Aldrich (1905), Jones cuss facial contour and the supposed absence of (1906), and Coquillett (1910a) presented short sec- vibrissae in Ephydridae. Frey (1921) discussed the tions on Nearctic Hydrellia. Very little additional mouthparts of H. obscura and the cibaria of other taxonomic study of the genus was made until 1915, ephydrids. Seguy (1934) illustrated the head and when Cresson started describing new species. Johann- wing of H. griseola, and Scotland (1940) illustrated sen (1935) has reviewed and presented a key to the by photographs the proboscis, antenna, and wing of known immature instars of Nearctic species. Hennig the closely