I^.Yry•^:.F- the UNIVERSITY of ILLINOIS LIBRARY

\i.^-^-^.: mm.i^.yry•^:.f- THE UNIVERSITY OF ILLINOIS LIBRARY NATURAL HISTORY SURVIY 5705 ILL V. Zcop.4 ^w^^Fm^^^^^ t ILLINOIS BIOLOGICAL MONOGRAPHS Vol. II January, 1916 No. 3 Editorial Committee Stephen Alfred Forbes William Trelease Henry Baldwin Ward Published under the Auspices of the Graduate School by THE University of Illinois Copyright, 1915 By the University of Illinois Distributed June 29, 1916 STUDIES ON GREGARINES Including Descriptions of Twenty-one New Species and a Synopsis of the Eugregarine Records from the Myriapoda, Coleoptera and Orthoptera of the World WITH FIFTEEN PLATES BY MINNIE ELIZABETH WATSON Contributions from the Zoological Laboratory of the Uniyersity of Illinois under the direction of Henry B. Ward No. 65 THESIS Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Zoology in the Graduate School of the University of Illinois 1915 TABLE OF CONTENTS INTRODUCTION page ^ Technic 7 Previous Work on Gregarines _ 9 List of Terms Used in Describing Gregarines „ 10 PART I BIOLOGY The Hosts Infected 12 Localities Represented 14 Seat of Infection 14 Seasonal Variation within the Host 15 Relation of Parasite to Host Tissue 16 Movement in Gregarines 20 Summary „ 20 PART II MORPHOLOGY OF GREGARINES Morphology of the Sporonts 27 The Stenophoridae 27 The Gregarinidae _ _ 30 Life History of a Typical Cephaline Gregarine 32 The Question of Sporont Maturity 33 The Cysts 34 Cyst Formation in the Gregarinidae Leidyana erratica 34 Cyst Development and Dehiscence 36 PART III SYNOPSIS OF THE EUGREGARINE RECORDS OF THE MYRIAPODA, COLEOPTERA, AND ORTHOPTERA OF THE WORLD Introduction _ 40 Brief Synopsis of the Families and Genera of the Tribe Cephalina (Delage) of the Suborder Eugregarinae (Leger) 43 Genera of Uncertain Position 48 Polycystid Gregarines in the Diplopoda 48 Polycystid Gregarines in the Chilopoda 80 Polycystid Gregarines in the Orthoptera 94 Polycystid Gregarines in the Coleoptera 128 Appendix An Unnamed Didymophes from a Japanese Beetle 198 6 ILLINOIS BIOLOGICAL MONOGRAPHS [216 PART IV THE CEPHALINE GREGARINES OF THE WORLD TO- GETHER WITH THEIR HOSTS 200 HOSTS WITH THEIR CEPHALINE GREGARIXE PARA- SITES 207 List of New Species 215 BIBLIOGRAPHY 216 EXPLANA TION OF PLA TES 221 INDEX 251 217] STUDIES ON GREGARINES— WATSON INTRODUCTION The following pages contain results from the study of a number of species of gregarines found as parasites in various Orthoptera, Coleop- tera, and Myriapoda during the past three years. The work was done chiefly in the zoological research laboratory of the University of Illinois, under the supervision of Professor Henry B. Ward. I am deeply in- debted to Professor Ward for his direction and helpful suggestions throughout. Four of the species described were found and studied at the Biological Laboratory of the Brooklyn Institute, Cold Spring Har- bor, Long Island, N. Y., and I wish to express my gratitude to Dr. C. B. Davenport for the opportunity of carrying on investigations at the Sta- tion. I wish also to thank Professor F. D. Barker, Professor H. B. Ba- ker, and Mr. Elmer Shafer for kindly sending me material from which parasites were obtained. The gregarines were studied in order to procure data in addition to that already known concerning (1) their biology including the habitat, relation to the host, seasonal distribution, and character of movement, (2) their modes of reproduction, and (3) their systematic position; twenty-two species are described for the first time while additional data is given for many more species. One result of the work was the compila- tion of a synopsis wherein are recorded in concise form the known facts concerning all the polycystid gregarines which literature records from the Orthoptera, Coleoptera, and Myriapoda of the world. A list was made of all the polcystid gregarines known, with their hosts, in order that species may not be recorded as new which have hitherto been discov- ered and that new species may not be given names which have already been used. TECHNIC The following method was used in studying the live parasites : The anterior and posterior extremities of the host are clipped off as close to the ends of the animal as possible and the alimentary tract is drawn out intact. It is then slit lengthwise with fine scissors, placed flat on a slide, and the masses of food and the parasites then teased out carefully to form a layer as thin and as nearly transparent as possible. Distilled water and normal salt solution were found to be the best media in which to observe the live gregarines. Plasmolysis is slower with 8 ILLINOIS BIOLOGICAL MONOGRAPHS [218 the former, while the parasites remain motile longer in the latter. A minimum amount of water or salt solution is used and a cover slip placed over the material to prevent rapid evaporation. The animals are now in an unnatural medium and will disintegrate rather rapidly, so sketches of those which are to be measured must be made with the camera lucida as soon as possible, using a minimum amount of light and a power of the miscroscope of about 100 diameters. When the parasites are nearly transparent, as are those of the species inhabiting the Coccinellidae, e. g., a drop of iodine-iodide solution will turn them brown and thus render a saffranin solution serves to out them visible ; weak bring in vivo the nucleus and sometimes the longitudinal striations. Although the parasites are best studied alive, some stained prepara- tions are valuable. In order to preserve parasites in toto for future * study, the intestine of the host is slit lengthwise and teased apart gently to loosen the fpod masses and the parasites. It is then dropped into the fixing solution and agitated gently when the free parasites will drop to the bottom of the dish. The best fixing agent is corrosive-sublimate solution to which has been added a trace of acetic acid; the precipitate is first washed with 50% alcohol and iodine, then with 70% and iodine, and the parasites preserved in 70% alcohol until needed. Picro-formol after Bouin was used in some instances with good results. For staining in toto, two methods are advisable. The slide may be smeared with a very small amount of egg albumen, the animals dropped upon it from a capillary pipette and the preparation placed horizontally in a dish of 35% alcohol for about two minutes to coagulate the albumen. It may then be carried very gradually down the alcohols to a water solution of Ehrlich's hematoxylin or to a rather weak alcoholic solution of borax-carmine and in the latter instance counter-stained with picric acid. The alcohols and stains should be placed in flat dishes so that the slide may be kept horizontal and gradualy immersed and withdrawn from each solution to insure against loss of the parasites. Many grades of alcohol should be used and the parasites kept in each alcohol about fifteen minutes. If the material is abundant, the parasites may be stained en masse in a small dish, since they settle to the bottom, but there is always con- siderable loss in the transfer of liquids. "When material is very scarce and all of the parasites must be kept, it is best to preserve simply in glycerine. Parasites from one host intestine can be placed on several slides, A weak mixture is made of glycerine and water and a very little of this used, the parasites being under ob- servation under the microscope the while, for it is very easy to add too much glycerine and in an instant destroy all the material. The water is very gradually withdrawn by adding a little glycerine for several sue- 219] STUDIES ON GREGARINES— WATSON 9 cessive days. A little safranin, erythrosin, or other stain may be added to the mixture and will be taken up by the parasites. The colored solution can be removed from the slide as the glycerine applications are made stronger. The study of totos should be supplemented as far as possible with sections. In the instance of the small species not visible to the eye, sections afford the only means of studying the exact location in the host. The whole alimentary tract is fixed and sectioned intact. Sections must be cut very thin, about two micra for the smaller species. Ehrlich's hematoxylin has been found the most satisfactory stain; it may be used alone or counter-stained with either erythrosin or eosin. Sections reveal the relation of the young parasite to the host cell, whether attached by an epimerite or intercellular, the position of the free sporonts in relation to the cell walls, and various points in structure of the sporonts. By means of sections the position of the sporont can be determined, whether inside or outside of the alimentary tract or its appendages. If the parasite is able to bore through the walls of the intestine into the coelom, the actual burrowing process is often depicted in a series of sections; Avhether the pyloric caBeca are a seat of infection is also revealed in this manner. PREVIOUS WORK ON GREGARINES In 1903 Minchin adequately summarized the history of gregarines from the time of Redi, who in 1708 recorded the discovery of what was possibly a gregarine, through Dufour, who gave in 1828 the first authen- tic account of these forms and named the genus which he found Grega- rina, up to the beginning of the present century. Other historians of the gregarines have been Lankester, in 1863, Butschli, in 1882, and Leger, in 1892. Like all groups of which little is known, much of the literature of the gregarines is purely systematic in character.

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