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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

An inaugural dissertation entitled observations on the structure and habits of the Lumbricus terrestris and a chemico-physiological enquiry on its respiration ... /

Green, Enoch A. January 1900 (has links)
Thesis (M.D.)--University of Pennsylvania, 1806. / Microform version available in the Readex Early American Imprints series.
2

Studies in Sparganophilus eiseni Smith

Hague, Florence Sander, January 1900 (has links)
Thesis (Ph. D.)--University of Illinois 1921. / Vita. "Contributions from the Zoological laboratory of the University of Illinois, no. 215." "Reprinted from Transactions of the American microscopical society, volume XLII, no. 1, January, 1923." "Literature cited": p. 34-38.
3

Earthworms in arable land methods for studying agricultural impact, especially pesticides = Daggmaskar i odlad jord : metoder för att studera jordbrukets inverkan, speciellt bekämpningsmedel /

Lofs-Holmin, Astrid. January 1983 (has links)
Thesis (doctoral)--Sveriges Lantbruksuniversitet. / Includes bibliographical references (p. 12).
4

The ecotoxicity of five insecticides to the Pheretima group (Oligochaeta) occurring on golf courses in the Pretoria region (South Africa)

Mostert, Magdalena Albertha 29 March 2006 (has links)
Earthworms have an important role to play in turfgrass. They aerify and enrich the soil, enhance water infiltration and break down thatch. Turfgrass managers are advised to select pesticides non-hazardous to earthworms to maintain the long-term stability of a healthy turf An artificial soil test was used to assess the toxicity of five insecticides, used for turf grass pest management, on the Pheretima group (Megascolecidae). The recommended application rates of carbaryl, chlorpyrifos, irnidacloprid, cyfluthrin and fipronil were tested. The LC50 values were also determined by using five dosages and a control (five replicates each) per insecticide. The dosages tested in the experiment were determined on a surface area basis. The effects of the tested insecticides on earthworm mortality, earthworm biomass and individual earthworm mass were assessed 24 hours, 48 hours and 7 days after application of the insecticides against the recommended application rate. Biomass and individual earthworm mass were also determined for dosages of the probit analysis where less than 30% mortality occurred. Individual mass was determined by dividing the biomass with the number of earthworm survivors per time interval per insecticide. Intoxication symptoms were noted. Carbaryl and chlorpyrifos (recommended application rates), had a significant greater effect on earthworm mortality than cyfluthrin, seven days after the application of the insecticides. No other significant earthworm mortality was found. None of the insecticides had a significant influence on earthworm biomass. Cyfluthrin initially reduced individual earthworm mass, but not biomass, more than the other insecticides. Carbaryl reduced biomass more than the other insecticides for all the assessments. Carbaryl, imidacloprid and chlorpyrifos had a larger negative effect than the control, fipronil and cyfluthrin on earthworm biomass and individual earthworm mass, for the 14 and 21 day assessments. For the 24 hour interval, carbaryl was the most toxic to earthworms (lowest LC50 of 77.2 mg kg-I), followed by imidacloprid (155.3 mg kg-I), cyfluthrin (350.7 mg kg-I), chlorpyrifos (389.9 mg kg-I) and fipronil (> 8550 mg kg-I) as the least toxic. For the 48 hour and 7 day intervals, imidacloprid was the most toxic to earthworms (LC50 values of 5.0 mg kg-I and 3.0 mg kg-I respectively), followed by carbaryl (15.7 mg kg-I; 9.0 mg kg-I), cyfluthrin (128.4 mg kg-1;110.2 mg kg-I), chlorpyrifos (330.0 mg kg-I; 180.2 mg kg-I) and the least toxic was fipronil (> 8550 mg kg-I both intervals). The biomass and individual earthworm mass were negatively influenced by chlorpyrifos, imidacloprid and cyfluthrin at higher dosages than the recommended application rate. Fipronil only had a significant effect on biomass and individual earthworm mass 24 hours after application at higher dosages than the recommended application rate. The intoxication symptoms noted were impaired activity, coiled and helical configurations, bleeding prostomiums and red sores. / Dissertation (MSc (Zoology and Entomology))--University of Pretoria, 2007. / Zoology and Entomology / unrestricted
5

An investigation into the growth and reproduction of the earthworm Lumbricus terrestris L. under controlled environmental conditions.

Butt, Kevin Richard. January 1990 (has links)
Thesis (Ph. D.)--Open University. BLDSC no. DX91237.
6

A physico-chemical study of four soil types under the influence of a number of leaf litters and earthworms species.

Leger, Roland Georges. January 1970 (has links)
No description available.
7

Soil microbial communities from the alimentary canal of the earthworm Lumbricus terrestris (Oligochaeta: lumbricidae)

Chapman, Joshua A. January 2006 (has links)
Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains viii, 75 p. : ill. (some col.), map. Includes abstract. Includes bibliographical references.
8

Bacterial challenge in Lumbricus terrestris a terrestrial invertebrate immunotoxicity model /

McDonald, Jennifer C. Venables, Barney J., January 2007 (has links)
Thesis (M.S.)--University of North Texas, May, 2007. / Title from title page display. Includes bibliographical references.
9

Parasitological studies : post-embryonic development in the polycercus of Paricterotaenia paradoxa (Rudolphi, 1802) in Allolobophora terrestris (Savigny, 1826)

Scott, James Stuart January 1963 (has links)
1. Metchnikov's discovery of Polycerus lubrici in the Earthworm, made in 1867, is confirmed for the first time. 2. The conclusion of Joyeux and Baer that Polycercus lumbrici is the larval form of Paricterotaenia paradoxa (= Amoebotaenia lumbrici) is confirmed. 3. The intermediate host is identified as Allolobophora terrestris and the principal final host as the Woodcock (Scolopax rusticola). 4. The polycercus has been found only in immature specimens of A. terrestris. The implications of this are discussed. 5. Earthworms were experimentally infested with Polycercus lumbrici by feeding them with mature proglottides of Paricterotaenia Paradoxa from the Woodcock. 6. The incidence and habits of the Woodcock are discussed. 7. The degree and site of infestation of Paricterotaenia paradoxa in the Woodcock are discussed. 8. The development of Polycerous lumbrici in the Earthworm, from the earliest form of the larva to the cysticercoid, is described in detail for the first time. 9. MetchniRov's outline of the development of Polvcercus lumbrici is amended to include a retroversion of the larva prior to the differentiation of the primordia of the scolex, retention of the side-walls of the larva and the appearance of an axial column of cells. His account is also extended to give, for the first time, a complete description of the development of the scolex. The rostellum is formed, as in Cysticercus fasciolars, from a bulb and prebulb, the former supplying the hook-elevator muscles and the glandular elements, the latter the muscles of the walls of the rostellum and the hook-retractor muscles. The remainder of the muscles of the scolex are modifications of the parenchymal and peripheral musculature. 10. The muscular, excretory, nervous and glandular systems are described and discussed. 11. A description is given of experiments to determine: (i) suitable media for keeping the larvae alive in vitro; (ii) agents for freeing the cysticercoids from the cyst; (iii) agents which induce evagination of the scolex; (iv) suitable media for culture and development of the evaginated tapeworms. The results of the experiments indicate that: (i) the larvae can be kept alive for periods of up to five days in simple physiological solutions such as Locke's (ii) the larvae are freed from the cyst in the gizzard of the final host by a purely mechanical process; (iii) the larvae are induced to evaginate in the final host by the action of gastric juice followed by pancreatic juice, the effective agents being pepsin in the first and pancreatin in the second, (iv) the tapeworm will not develop to maturity in any of the media used. 12. The discovery of a second polycercus, the larval form of Paricterotaenla burti Sandeman, 1959 is recorded from the Earthworm Allolophora terrestris. 13. Hook development in Paricterotaenia burti is described it follows the same general pattern as that of P. paradoxa. 14. An unidentified species of Amoebotaenia is described. 15. Evidence is offered which elucidates the life-cycles of the following cestodes: (i) Paricterotaenia paradoxa: intermediate host, the Earthworm Allolobophora terrestris; final host, the Woodcock (Scolopax rusticola). (ii) Parieterotaenia burti; intermediate host, the Earthworm Allolobophora terrestris; final host, the Woodcock (Scolopax rustlcola). (iii) Paricterotaenia stelliferai: final host, various charadrriform birds; intermediate host, Tubifex. Cysticercus pachycanthus is identified as the larval form of Valipora skrjabini a parasite of the Common Snipe (Gallinago gallinago). An unrecorded cyrsticercoid from Tubifox is noted.
10

An investigation into the growth and reproduction of the earthworm Lumbricus terrestris L. under controlled environmental conditions

Butt, Kevin Richard January 1990 (has links)
Earthworm inoculation for soil amelioration has been shown to be valuable in a range of experiments. At present, inoculation on a large scale is limited by the supply of larger deep-burrowing species of earthworm. This work aimed to assess the feasibility of intensively producing deep-burrowing earthworms for soil amelioration projects. Lwnbricus terrestris, whose behaviour is well documented, was chosen. The scientific literature was used to identify points within the life cycle of this earthworm where manipulation of conditions might lead to increased rates of production. Feed quality, environmental temperature, time of year, population density and age of breeding stock were all recognised as important variables. Experiments were performed to identify the optimal conditions for L.rerrestris reproduction, cocoon development and growth. Results suggested that reproduction would occur throughout the year and mean annual figures of 37 cocoons per worm were recorded from intensively produced earthworms. Recently matured worms showed greatest levels of cocoon production. As previously reported seasonal variation in reproduction was found even at constant temperature. Cocoon development was most rapid at a temperature of 20°C, taking 70 days, with a cocoon viability of 83%. Growth from a mean hatchling weight of 53mg to sexual maturity at 5g, took twelve weeks. Growth at constant temperatures of 15 and 20°C was not significantly different. A synthetic feed, with a carbon to nitrogen ratio of 40:1, created from paper waste and yeast extract, led to greatest recorded figures for both growth and cocoon production. The results suggest that an intensive production system is technically feasible, and the economic viability needs to be tested.

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