The life-cycle of the compost worm

To determine the full potential of the compost worm Eisenia fetida as waste processor and as source of protein, the life-cycle of this species had to be studied thoroughly. The development, growth and reproduction of Eisenia fetida were studied on cattle manure under favourable conditions of moisture, temperature and nutrition. Data were gathered over a period of 600 days. Apart from the life-cycle this study also indicated that this species can be reproductively active for more than 500 days. This is significantly longer than had previously been believed. Each cocoon produced a mean of 2,7 hatchlings after a mean incubation period of 23 days. These worms attained sexual maturity after 40 to 60 days and produced their first cocoons within four days after mating took place

The effect of high lead concentrations on the mortality, mass and behaviour of Porcellio laevis Latr. (Crustacea, Isopoda) in laboratory tests

The aim of this study was to determine the effects of high lead concentrations on the terrestrial isopod Porcellio laevis and to determine whether these animals could distinguish between lead contaminated and uncontami-nated leaves. In the acute toxicity tests the isopods were exposed to 0, 15, 30,45, 60, 75, 90 and 105 g/kg lead nitrate. Behavioural tests were conducted exposing the isopods to 0, 15 and 105 g/kg lead nitrate. In the acute toxicity tests the various concentrations differed significantly concerning mortality and weight loss of surviving isopods. The LC50 after 14 days exposure for P. laevis was 87.4 g/kg. The LC50 values obtained in this study are extremely high compared to those of earthworms. This is an indication of high tolerance for lead. The concentrations of lead found in the isopods were high and could give a possible explanation for the mortalities and mass losses observed, as lead at those concentrations could have disturbed the normal physiological functioning of the animals. The isopods avoided lead contaminated leaves in the behavioural tests, which could cause accumulation of leaf litter and thus a reduction of the decomposition rate

Moisture preferences, growth and reproduction of the African nightcrawler, Eudrilus eugeniae (Oligochaeta)

As part of a comprehensive study of the biology of the economically important earthworm species Eudrilus eugeniae, the water relations of this species were studied. Moisture preferences were studied with the aid of cylindrical moisture towers filled with cattle manure. The cattle manure was dried, ground to a particle size of 500> <1000 (im and moistened. A moisture gradient was allowed to develop in the towers, the worms were added and the towers kept in an environmental control chamber at a temperature of 25°C and a relative humidity of 80%. The moisture preferences of both juvenile and adult worms were studied. The clitellate worms showed a wider preference range than the juveniles and the preference range of the juveniles coincided with the moisture levels at which cocoons were deposited. The highest frequency of occurrence for clitellate worms was between moisture levels of 80 and 82%. For cocoon deposition the highest frequency was at moisture levels between 79 and 80,5% and most juvenile worms showed a preference for a moisture range between 77,5 and 79%. The cocoons produced were incubated and the number of hatchlings per cocoon noted. The biggest number of offspring per cocoon hatched from cocoons originating from the moisture range of 79 to 80,5% coinciding with the highest frequency of cocoon deposition. From the results it appears that this earthworm species could be utilized in organic waste material with a relatively high moisture content

Life-cycle of the African nightcrawler, Eudrilus eugeniae (Oligochaeta)

In order to determine the potential of the earthworm Eudrilus eugeniae as waste processor and protein producer, the life history of this species was studied. The development, growth and reproduction of E. eugeniae were studied. Cattle dung was used as substrate with a moisture content of 70–80% and a temperature of 25°C. Data were gathered over a period of 300 days. It was found that cocoon production started within 24 h after copulation and can be sustained for at least 300 days. Cocoons are produced at an average rate of 1,65 cocoons per worm per day. The mean incubation period of cocoons is 16,6 days with a hatching success of 84% and 2,7 hatchlings per cocoon that hatched. Sexual maturity is attained by the offspring within 40 to 50 days after hatching. E. eugeniae is compared to other vermicomposting species

The weakening of eggshells of the laughing dove, Streptopelia senegalensis (Linn.)

Eggshells of Streptopelia senegalensis dating from 1899 to 1983 were studied to determine whether a change had occurred in the mass of the shells, the length section, breadth (width) section, thickness and index. A significant difference was determined in both mass and index of the more recent eggs (after 1957) compared with older eggs. The two groups of eggs represent periods prior and subsequent to the introduction of agricultural pesticides in southern Africa. Although no definite link has been established the results merit further experimental studies to determine whether the observed changes could be ascribed to the increased usage of agricultural pesticides

Life Cycle of the Oriental Compost Worm Perionyx Excavatus (Oligochaeta)

In order to exploit the concept of using vermiculture as biotechnology for waste control and protein production, the life cycle of the vermicomposting species, Perionyx excavatus, was studied. The development, growth and reproduction of P. excavatus  were investigated. Urine free cattle manure with a moisture content of 76-83% and a temperature of 25°C was used as substrate. Data were gathered over a period of 300 days. It was found that mating is not a prerequisite for cocoon production, which starts at the mean age of 24 days. Maturation was attained at the age of approximately 21 days. Cocoons were produced at a mean rate of 1,1 cocoons per worm per day. The mean incubation period of cocoons produced by batches of worms was 18,7 days with a mean hatching success of 63,4%. The mean incubation period of cocoons produced by single worms was 20,4 days with a mean hatching success of 40,4%. As a rule only one worm hatched per cocoon. The life cycle of this species is presented diagrammatically

Life-cycle of the European compost worm Dendrobaena veneta (Oligochaeta)

The life-cycle of Dendrobaena veneta was studied to assess the potential of this species in vermiculture. The development, growth and reproduction were investigated by rearing worms at 25°C on urine-free cattle manure with a moisture content of 80% over a period of 200 days. It was found that cocoons are produced at a mean rate of 0,28 cocoons per worm per day and production can be sustained for at least 200 days. The mean incubation period of the cocoons is 42,1 days with a very low hatching success. The mean number of hatchlings per cocoon that hatched was 1,1. Sexual maturity may be attained within 20 to 35 days but some worms take up to 130 days. Dendrobaena veneta grew well on cattle manure. This species seems to be less suitable than some other epigeic species for vermiculture, at least in terms of its reproductive capacity in the experimental climatic conditions

A modification of standard procedures for evaluating the relative efficacy of anthelmintics

1. The modified critical test, or so-called short-term slaughter test, was the most suitable means of assessing anthelmintic efficacy on adult Trichostrongylus spp. and O. columbianum. It has some value for O. circumcincta but is unsatisfactory on H. contortus. 2. The modified controlled test was the best method of testing the effects of anthelmintics on immature worms. It is the method of choice on all stages of development of H. contortus.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Book Reviews

Book Review 1Book Title: Early Life Histories of Fishes: New Developmental, Ecological and Evolutionary PerspectivesBook Author: Edited by E.K. BalonDr W. Junk, Dordrecht. 280 pp.Book Review 2Book Title: Comparative Aspects of Extracellular Acid-base BalanceBook Author: J.P. TruchotSpringer, 1987. 248 pp. 51 figures.Book Review 3Book Title: Insect Flight: Dispersal and MigrationBook Author: Edited by W. DanthanarayanaSpringer-Verlag, Berlin, 1986. 289 pp.Book Review 4Book Title:  The Mammalian Herbivore Stomach. Comparative Anatomy, Function and EvolutionBook Author: Peter LangerGustav Fischer, Stuttgart, 1988. 557 pages, 246 figures and 72 tablesBook Review 5Book Title:  Biology of the Integument. Vol. 2: VertebratesBook Authors: Edited by J. Bereiter-Hahn, A.G. Matoltsy & K.S. RichardsSpringer, Berlin, 1986. 855 pp.Book Review 6Book Title:  Advances in the Biology of Turbellarians and related PlatyhelminthesBook Author: Edited by Seth TylerDr. W. Junk Publishers, 1986. 357 pages; 253 figuresBook Review 7Book Title: Evolutionary Physiological EcologyBook Author: Edited by P. CalowCambridge University Press, Cambridge. 239 pp.Book Review 8Book Title: DragonfliesBook Author: Peter L. MillerCambridge University Press, Cambridge, New York and Melbourne, 1987. 84 pp

Book Reviews

Book Review 1Book Title: Megaherbivores: the influence of very large body size on ecologyBook Author: R.N. Owen-SmithCambridge University Press, Cambridge, 1988. 369 pages.Book Review 2Book Title: Comparative Physiology of the Vertebrate KidneyBook Author: W.H. Dantzler Springer-Verlag 1989.198 pp. (Hardcover).Book Review 3Book Title: Atlas on the Biology of Soil ArthropodsBook Authors: G. Esenbeis & W. Wichard Springer-Verlag, Berlin 1987. 437 pp.Book Review 4Book Title: Primate Vocal CommunicationBook Authors: Edited by D. Todt, P. Goedeking & D. SymmesSpringer Verlag, Berlin (1988)Book Review 5Book Title: The Honey BeeBook Authors: J.L. Gould & C. G. GouldScientific American Ubrary, W.H.Freeman, New York. 239 pp.Book Review 6Book Title: Insect Development Photoperiodic and Temperature ControlBook Author: Victor A. ZaslavskiSpringer-Verlag, Berlin. 187 pp.Book Review 7Book Title: OrganellesBook Author: Mark CarrollMacmillan 1989. 202 pp.Book Review 8Book Title: Comparative Protozoology Ecology, Physiology, Life HistoryBook Author: O. Roger AndersonSpringer-Verlag, Berlin, 1988. 482pp.Book Review 9Book Title: Ecotoxicology: Problems and ApproachesBook Authors: Edited by S.A. Levin, M.A. Harwell, J.R. Kelly & K.D. KimballSpringer Verlag, New York. 547 pp