Journal of Parasitology 

Abstract: We consider 27 population and community terms used frequently by parasitologists when describing the ecology of parasites. We provide suggestions for various terms in an attempt to foster consistent use and to make terms used in parasite ecology easier to interpret for those who study free-living organisms. We suggest strongly that authors, whether they agree or disagree with us, provide complete and unambiguous definitions for all parameters of their studies.

Abstract: Synchronous development of the erythrocytic stages of a human malaria parasite, Plasmodium falciparum, in culture was accomplished by suspending cultured parasites in 5% D-sorbitol and subsequent reintroduction into culture. Immediately after sorbitol treatment, cultures consisted mainly of single and multiple ring-form infections. At the same time, varying degrees of lysis of erythrocytes infected with the more mature stages of the parasite was evident. Approximately 95% of the parasites were in the ring stage of development at 48 and 96 hr after sorbitol treatment-likewise, a high percentage of trophozoite and schizont stages was observed at 24, 72, and 120 hr. D-Mannitol produced similar, selective, lytic effects.

Abstract: In February 1981, ASP President Elmer Noble on recommendation from the Editor, Austin Maclnnis, appointed an ad hoc committee \"to establish working definitions of a few terms used and misused by parasitological ecologists\" as a guide for authors submitting papers to The Journal of Parasitology. Appointed to the committee were Drs. Gerald Esch, John Holmes, Armand Kuris, Gerhard Schad, and Leo Margolis (Chairman). As a starting point the committee examined the recommendations (Margolis et al., 1982) prepared by a similar committee established by the Parasitology Section of the Canadian Society of Zoologists. The Canadian Committee concerned itself only with terms required to express concepts related to the number of hosts in a sample infected with a particular species of parasite, and to the number of individuals of a particular parasite in each host in a sample. As noted below the present committee also dealt with several other ecological terms that are not now being used in a consistent manner in parasitological literature. The following are the committee's recommendations, annotated as required:

Abstract: In this study of arthropod predador-prey systems Michael Hassell shows how many of the components of predation may be simply modeled in order to reveal their effects on the overall dynamics of the interacting populations Arthropods, particularly insects, make ideal subjects for such a study because their generation times are characteristically short and many have relatively discrete generations, inviting the use of difference equation models to describe population changes Using analytical models framed in difference equations, Dr Hassell is able to show how the detailed biological processes of insect predator-prey (including host-parasitoid) interactions may be understood Emphasizing the development and subsequent stability analysis of general models, the author considers in detail several crucial components of predator-prey models: the prey's rate of increase as a function of density, non-random search, mutual interference, and the predator's rate of increase as a function of predator survival and fecundity Drawing on the correspondence between the models and field and laboratory data, Dr Hassell then discusses the practical implications for biological pest control and suggests how such models may help to formulate a theoretical basis for biological control practices