Phenotypic Plasticity of Cuticular Hydrocarbons in Herbivorous Insects


Book Description

Speciation of herbivorous insects may be driven by specialization on host plants. Plasticity in host plant preferences might promote sympatric speciation of herbivorous insects if plants affect mating signals and thus, lead to assortative mating. The general aim of this thesis is to understand the causes and consequences of phenotypic plasticity of mating recognition systems of herbivorous insects. The investigated species are the syntopic leaf beetles Phaedon cochleariae and P. armoraciae which have a common host plant range, but use divergent host species when occurring at the same site. Their sexual behavior is mediated by their cuticular hydrocarbon (CHC) profiles which function as contact pheromones for mate and species recognition. Behavioral bioassays and chemical analyses are used to study the question whether the host plant species affects the CHC pattern of the beetles, and thus, their mate recognition. Within a species, males prefer mating with females feeding on the same host plant species to mating with females feeding on an alternative host plant. Sexual isolation between species ceases when beetles feed upon the same host plant species. A discriminant analysis reveals that the beetles' quantitative composition of CHC profiles clearly differ in dependence of sex, host plant and insect species. However, the profiles of the two beetle species are more similar when feeding upon the same host plant species. These findings give rise to the idea that plant-induced phenotypic divergence in mate recognition cues of herbivorous insects may act as an early barrier to gene flow between insect populations on different host species, thus preceding genetic divergence and thus, promoting ecological speciation







Insect Hydrocarbons


Book Description

A unique and critical analysis of the wealth of research conducted on the biology, biochemistry and chemical ecology of the rapidly growing field of insect cuticular hydrocarbons. Authored by leading experts in their respective fields, the twenty chapters show the complexity that has been discovered in the nature and role of hydrocarbons in entomology. Covers, in great depth, aspects of chemistry (structures, qualitative and quantitative analysis), biochemistry (biosynthesis, molecular biology, genetics, evolution), physiology, taxonomy, and ecology. Clearly presents to the reader the array of data, ideas, insights and historical disagreements that have been accumulated during the past half century. An emphasis is placed on the role of insect hydrocarbons in chemical communication, especially among the social insects. Includes the first review on the chemical synthesis of insect hydrocarbons. The material presented is a major resource for current researchers and a source of ideas for new researchers.




Insect-Plant Biology


Book Description

"Half of all insect species are dependent on living plant tissues, consuming about 10% of plant annual production in natural habitats and an even greater percentage in agricultural systems, despite sophisticated control measures. Plants are generally remarkably well-protected against insect attack, with the result that most insects are highly specialized feeders. The mechanisms underlying plant resistance to invading herbivores on the one side, and insect food specialization on the other, are the main subjects of this book. For insects these include food-plant selection and the complex sensory processes involved, with their implications for learning and nutritional physiology, as well as the endocrinological aspects of life cycle synchronization with host plant phenology. In the case of plants exposed to insect herbivores, they include the activation of defence systems in order to minimize damage, as well as the emission of chemical signals that may attract natural enemies of the invading herbivores and may be exploited by neighbouring plants that mount defences as well." "Insect-Plant Biology discusses the operation of these mechanisms at the molecular and organismal levels, in the context of both ecological interactions and evolutionary relationships. In doing so, it uncovers the highly intricate antagonistic and mutualistic interactions that have evolved between plants and insects. The book concludes with a chapter on the application of our knowledge of insect-plant interactions to agricultural production." "This multidisciplinary approach will appeal to students in agricultural entomology, plant sciences, ecology, and indeed anyone interested in the principles underlying the relationships between the two largest groups of organisms on earth: plants and insects."--BOOK JACKET.Title Summary field provided by Blackwell North America, Inc. All Rights Reserved




Neurobiology of Chemical Communication


Book Description

Intraspecific communication involves the activation of chemoreceptors and subsequent activation of different central areas that coordinate the responses of the entire organism—ranging from behavioral modification to modulation of hormones release. Animals emit intraspecific chemical signals, often referred to as pheromones, to advertise their presence to members of the same species and to regulate interactions aimed at establishing and regulating social and reproductive bonds. In the last two decades, scientists have developed a greater understanding of the neural processing of these chemical signals. Neurobiology of Chemical Communication explores the role of the chemical senses in mediating intraspecific communication. Providing an up-to-date outline of the most recent advances in the field, it presents data from laboratory and wild species, ranging from invertebrates to vertebrates, from insects to humans. The book examines the structure, anatomy, electrophysiology, and molecular biology of pheromones. It discusses how chemical signals work on different mammalian and non-mammalian species and includes chapters on insects, Drosophila, honey bees, amphibians, mice, tigers, and cattle. It also explores the controversial topic of human pheromones. An essential reference for students and researchers in the field of pheromones, this is also an ideal resource for those working on behavioral phenotyping of animal models and persons interested in the biology/ecology of wild and domestic species.




Entomology Abstracts


Book Description




Pines and Their Mixed Forest Ecosystems in the Mediterranean Basin


Book Description

Almost 20 years after the first MEDPINE book "Ecology, biogeography and management of Pinus halepensis and P. brutia forest ecosystems in the Mediterranean basin "(Ne'eman and Trabaud, 2000) was published, this new book presents up-to-date and state of the art information, covering a wide range of topics concerning Mediterranean pine trees growing in native and planted forests, their ecosystems and management. This will be an essential source of scientific information for learning, exploring planning and managing mediterranean pine and mixed forests. We focus on: genetics, adaptation, distribution and evolution; ecophysiology and drought resistance; pine and mixed forest ecosystems; forest dynamics biodiversity and biotic interactions; fire ecology; ecosystem services and policy; afforestation and management; all under the effect of global climate change. While forests are studied mainly in temperate and tropical zones, in the light of current climate change, focusing on Mediterranean forests growing in semi-humid to semi-arid zones is more important than ever. This book will include mostly review chapters (and two outstanding case studies) contributed by leading scientists, foresters and managers, and will serve as a scientific textbook for students of biology, agriculture and forestry, researchers of ecology forestry and related fields, forest managers, policy and decision makers.




Chemical Ecology of Insects


Book Description

Our objective in compiling a series of chapters on the chemical ecology of insects has been to delineate the major concepts of this discipline. The fine line between presenting a few topics in great detail or many topics in veneer has been carefully drawn, such that the book contains sufficient diversity to cover the field and a few topics in some depth. After the reader has penetrated the crust of what has been learned about chemical ecology of insects, the deficiencies in our understanding of this field should become evident. These deficiencies, to which no chapter topic is immune, indicate the youthful state of chemical ecology and the need for further investigations, especially those with potential for integrating elements that are presently isolated from each other. At the outset of this volume it becomes evident that, although we are beginning to decipher how receptor cells work, virtually nothing is known of how sensory information is coded to become relevant to the insect and to control the behavior of the insect. This problem is exacerbated by the state of our knowledge of how chemicals are distributed in nature, especially in complex habitats. And finally, we have been unable to understand the significance of orientation pathways of insects, in part because of the two previous problems: orientation seems to depend on patterns of distri bution of chemicals, the coding of these patterns by the central nervous system, and the generation of motor output based on the resulting motor commands.




Plant Communication from an Ecological Perspective


Book Description

Since the concept of allelopathy was introduced almost 100 years ago, research has led to an understanding that plants are involved in complex communicative interactions. They use a battery of different signals that convey plant-relevant information within plant individuals as well as between plants of the same species or different species. The 13 chapters of this volume discuss all these topics from an ecological perspective. Communication between plants allows them to share physiological and ecological information relevant for their survival and ?tness. It is obvious that in these very early days of ecological plant communication research we are illuminating only the ‘tip of iceberg’ of the communicative nature of higher plants. Nevertheless, knowledge on the identity and informative value of volatiles used by plants for communication is increasing with breath-taking speed. Among the most spectacular examples are sit- tions where plant emitters warn neighbours about a danger, increasing their innate immunity, or when herbivore-attacked plants attract the enemies of the herbivores (‘cry for help’ and ‘plant bodyguards’ concepts). It is becoming obvious that plants use not only volatile signals but also diverse water soluble molecules, in the case of plant roots, to safeguard their evolutionary success and accomplish self/non-self kin rec- nition. Importantly, as with all the examples of biocommunication, irrespective of whether signals and signs are transmitted via physical or chemical pathways, plant communication is a rule-governed and sign-mediated process.




Aphids as Crop Pests, 2nd Edition


Book Description

Aphids are among the major global pest groups, causing serious economic damage to many food and commodity crops in most parts of the world. This revision and update of the well-received first edition published ten years ago reflects the expansion of research in genomics, endosymbionts and semiochemicals, as well as the shift from control of aphids with insecticides to a more integrated approach imposed by increasing resistance in the aphids and government restrictions on pesticides. The book remains a comprehensive and up-to-date reference work on the biology of aphids, the various methods of controlling them and the progress of integrated pest management as illustrated by ten case histories.