Population Dynamics Of The Flour Beetle Tribolium Castaneum Herbst

Population dynamics of red flour beetles, Tribolium castaneum (Herbst) was determined using three different sizes of grain patch (bulk), specifically, small (0.03 kg wheat), medium (2 kg wheat) and large (14 kg wheat), at different temperature profiles. The temperature profiles tested were 21, 25, 30, 35 ̊C, T-decrease (30 ̊C in the first 4 weeks and then decreased 1 ̊C /week to -10 ̊C) and T-increase (21 ̊C in the first two weeks and then increased 1 ̊C /week to 38 ̊C). Three male and three female adults were introduced into each grain patch (bulk) at the start of experiments. Numbers of adults in the grain patch (bulk) were counted every 28 days up to 30 weeks. The population dynamics of the Tribolium castaneum (insect numbers) were strongly influenced by the temperature profiles, storage time and grain patch (bulk) size. The insect population increased after 4 week of introduction inside all the grain patches. Later, the number of both offspring and adults showed drastic variation with respect to temperature and storage time under different patch sizes. The peak number or density of insects also showed variation with time for different temperatures and patch sizes. The peak live adult density was the highest in the small patch at each temperature profile. The peak live adult density in the small patch was 300 ± 50, 673 ± 118, 689 ± 48, 1100 ± 150, 1150 ± 150 and 1133 ± 94 adults/kg at 21, 25, 30, 35 ̊C, T-decrease and T-increase, respectively.

The study of populations is becoming increasingly focused on dynamics. We believe there are two reasons for this trend. The ftrst is the impactof nonlinear dynamics with its exciting ideas and colorful language: bifurcations, domains of attraction, chaos, fractals, strange attractors. Complexity, which is so very much a part of biology, now seems to be also a part of mathematics. A second trend is the accessibility of the new concepts. Thebarriers tocommunicationbetween theoristandexperimentalistseemless impenetrable. The active participationofthe experimentalist means that the theory will obtain substance. Our role is the application of the theory of dynamics to the analysis ofbiological populations. We began our work early in 1979 by writing an ordinary differential equation for the rateofchange in adult numbers which was based on an equilibrium model proposed adecadeearlier. Duringthenextfewmonths weftlledournotebookswithstraightforward deductions from the model and its associated biological implications. Slowly, some of the biological observations were explained and papers followed on a variety of topics: genetic and demographic stability, stationary probability distributions for population size,population growth asabirth-deathprocess, natural selectionanddensity-dependent population growth, genetic disequilibrium, and the stationary stochastic dynamics of adult numbers.

Population Dynamics and Laboratory Ecology highlights the contributions laboratory studies are making to our understanding of the dynamics of ecological and evolutionary systems. Chapters address the scientific rationale for laboratory ecology, its historical role within the broader discipline, and recent advances in research. The book presents results from a wide range of laboratory systems including insects, mites, plankton, protists, and microbes. A common theme throughout the book is the value of microcosm studies in advancing our knowledge of ecological and evolutionary principles. Each chapter is authored by scientists who are leading experts in their fields. The book addresses fundamental questions that are of interest to biologists whether they work in the laboratory or field or whether they are primarily empiricists or theorists. Details a scientific rationale for laboratory systems in ecological and evolutionary studies Offers a view on historical role of laboratory studies Includes examples of recent research advances in ecology and evolution using laboratory systems, ranging from insects to microbes Integrates mathematics, statistics and experimental studies

Why do organisms become extremely abundant one year and then seem to disappear a few years later? Why do population outbreaks in particular species happen more or less regularly in certain locations, but only irregularly (or never at all) in other locations? Complex population dynamics have fascinated biologists for decades. By bringing together mathematical models, statistical analyses, and field experiments, this book offers a comprehensive new synthesis of the theory of population oscillations. Peter Turchin first reviews the conceptual tools that ecologists use to investigate population oscillations, introducing population modeling and the statistical analysis of time series data. He then provides an in-depth discussion of several case studies--including the larch budmoth, southern pine beetle, red grouse, voles and lemmings, snowshoe hare, and ungulates--to develop a new analysis of the mechanisms that drive population oscillations in nature. Through such work, the author argues, ecologists can develop general laws of population dynamics that will help turn ecology into a truly quantitative and predictive science. Complex Population Dynamics integrates theoretical and empirical studies into a major new synthesis of current knowledge about population dynamics. It is also a pioneering work that sets the course for ecology's future as a predictive science.

In the summer of 1993, twenty-six graduate and postdoctoral stu dents and fourteen lecturers converged on Cornell University for a summer school devoted to structured-population models. This school was one of a series to address concepts cutting across the traditional boundaries separating terrestrial, marine, and freshwa ter ecology. Earlier schools resulted in the books Patch Dynamics (S. A. Levin, T. M. Powell & J. H. Steele, eds., Springer-Verlag, Berlin, 1993) and Ecological Time Series (T. M. Powell & J. H. Steele, eds., Chapman and Hall, New York, 1995); a book on food webs is in preparation. Models of population structure (differences among individuals due to age, size, developmental stage, spatial location, or genotype) have an important place in studies of all three kinds of ecosystem. In choosing the participants and lecturers for the school, we se lected for diversity-biologists who knew some mathematics and mathematicians who knew some biology, field biologists sobered by encounters with messy data and theoreticians intoxicated by the elegance of the underlying mathematics, people concerned with long-term evolutionary problems and people concerned with the acute crises of conservation biology. For four weeks, these perspec tives swirled in discussions that started in the lecture hall and carried on into the sweltering Ithaca night. Diversity mayor may not increase stability, but it surely makes things interesting.