Communication And Pheromones

Ants have diverse systems of communication, but by far the most important medium for signaling involves the chemicals known as pheromones. Ants can deposit chemical trails to recruit nestmates to discoveries of food. Many ants can also produce highly volatile chemicals to signal alarm when they encounter dangerous predators or other hazands. Different ants in different subfamilies use a remarkable diversity of glandular structures even just to produce recruitment pheromones. These may be...

Cockroach Control

There are several considerations that come into play in any discussion of cockroach control. The first is understanding how infestations arise. The usual modes of entry for German and brown-banded cockroaches are through infested parcels containing food or other materials, and by movement from abutting dwellings. Most of the other, larger pest species tend to live outdoors and can move from one building to another. They can also be introduced in parcels. Thus, the next consideration is...

Structure

In the classic textbook interpretation, the insectan leg has six well-sclerotized segments, arranged proximal to distal the coxa, trochanter, femur, tibia, tarsus, and pretarsus. A more fundamental and complete segmentation scheme, which facilitates the recognition of leg and leg-derived homologies among all arthropods, involves 10 or 11 segments. These segments include the epicoxa (debatably present as the wing articulation and a fused portion of the tergum), subcoxa (absorbed into the...

Ecological Specialization

One means of estimating the ground plan feeding habits of Coleoptera uses observations of extant taxa, interpreted in context of phylogenetic hypotheses for the various lineages making up the order. By this method, we would deduce that the most primitive beetles were either saprophagous wood borers as larvae, such as extant Archostemata, or that they were campodeiform predators, such as the Adephaga and the sister group to Coleoptera, the Neuroptera+Raphidioptera+ Neuroptera. Examining the...

Habitats

Crickets live in virtually all terrestrial habitats from treetops to a meter or more beneath the ground. Members of multiple subfamilies live in or near treetops and in bushes, grasses, and other herbaceous plants (Oecanthinae, Mogoplistinae, Eneopterinae, Podoscirtinae, Trigonidiinae) (Fig 3) on the soil surface (Nemobiinae, Gryllinae) in caves (Phalangopsinae, Pentacentrinae) and in shallow or deep burrows (Gryllotal- FIGURE 3 Adult male Orocharis saltator. (Photograph courtesy of David H....

Passive Traps

The sundews capture their prey by producing from stalked glands an adhesive, or glue (the drop of dew), which captures and holds fast the insect. As the prey struggles, it is covered with the sticky mucilage, and as a consequence, suffocates. The stalked glands then bend in toward the prey in some species, the entire leaf enfolds the prey. A second type of gland on the leaf secretes digestive enzymes and acids, initiating the breakdown and subsequent absorption of nutrients. Darwin was so...

Japanese Beetle

The Japanese beetle, Popilliajaponica, is among the most polyphagous of plant-feeding insects. The adults skeletonize the foliage, or feed on the flowers or fruits, of nearly 300 species of wild or cultivated plants. Favored hosts include many woody and herbaceous landscape plants, garden plants, fruits, and field crops. The larvae, or grubs, develop in the soil where they feed on roots of turf and pasture grasses, vegetables, nursery seedlings, and field crops. Hundreds of millions of dollars...

Significance Of Fleas

Fleas are important to humans because of their potential as disease vectors, in addition to the annoyance they produce merely by biting. Pathogen transmission is facilitated by their habit of feeding sequentially on several hosts. The best known disease associated with fleas is bubonic plague the plague bacterium, Yersiniapestis, is transmitted almost exclusively by rodent fleas. Murine typhus is another disease for which cat fleas have been implicated in the transmission cycle. The flea-borne...

Polygenic Industrial Melanism

Of all categories of melanism, polygenic industrial melanism has been the least considered and is the most difficult to address. Examination of specimens collected over the past century and a half suggests that many species have experienced a gradual darkening of the colors and loss of patterning in industrial regions, irrespective of morph. Although some of this change may be attributed to the gradual fading that occurs in museum specimens with time, it is difficult to ascribe all of the...

Organization At The National Level

At the national level, the Cooperative Extension Service is an integral part of the Cooperative State Research, Education, and Extension Service (CSREES). The CSREES is a national research and education network that links education programs of the U.S. Department of Agriculture with land-grant institutions, with 1890 institutions, with agricultural experiment stations, with Cooperative Extension Services, with schools of forestry, and with colleges of agriculture, colleges of veterinary...

Midgut Secretory Mechanisms

Insects are continuous (e.g., Lepidoptera and Diptera larvae) or discontinuous (e.g., predators and hematophagous insects) feeders. Synthesis and secretion of digestive enzymes in continuous feeders seem to be constitutive that is, these functions occur continuously, whereas in discontinuous feeders they are regulated. It is widely believed (without clear evidence) that putative endocrine cells (Fig. 3I) occurring in the midgut could, like similar cells in vertebrates, play a role in regulating...

Info

Similar differences have been recorded in and Grant et al, 1995, 1996). In the 1950s, anti-pollution legislation was introduced in industrial countries on both sides of the Atlantic. This legislation led to declines in both sulfur dioxide and particulate soot emissions. Subsequently, the frequencies of the melanic forms have declined considerably in industrial regions in Britain (Table I). Current rates of decline are broadly in line with theoretical predictions using computer...

Deterministic Evolution via Immediate Benefits

Neophobia A new aposematic form could in theory escape the disadvantage of being rare and novel by causing immediate avoidance without having to be tasted at all by the predator. Indeed, predators are somewhat reluctant to sample novel-looking prey, particularly if novelty is associated with bright colors. This phenomenon is called neophobia, a kind of diet conservatism in predators. Neophobia could arise from various foraging biases, such as the formation of search images in the brains of...

Role Of Insects In Forest Succession

Although trees can live for thousands of years (e.g., giant sequoia, Sequoiadendrongigantea), natural forests are dynamic plant communities that can change very slowly over thousands of years or very quickly over a few days to a few years. Fires, volcanic eruptions, strong winds, and snow and ice often have dramatic effects on forest succession. Insects can also have this effect during outbreaks (referred to as epidemics or gradations). For example, bark beetles, together with their associated...

Context Of Anatomical Study

Terms of Orientation and Conventions Terms to describe orientation are not intuitive for insects. Most orientation terms are derived from the study of the human body a body that stands upright and their application to insects causes confusion. Some standard terms used with insects include anterior (in front), posterior (behind), dorsal (above), ventral (below), medial (middle), and lateral (side). Anatomical description usually follows in the same order, hence, we begin our discussion with the...

How To Measure Insects

Body length (measured from tip of head to tip of abdomen) is probably the most often used measure of size and the easiest to comprehend. Weight (or biomass) is a measure of size that interests many ecologists because it often correlates well with fecundity. Fecundity, in turn, is often a major fitness component and may be a key feature in population dynamics. For practical reasons, traits that are correlated with weight are used instead, such as hind tibia length, front wing length, elytra...

Genetic Engineering In Drosophila Melanogaster

Genetic Technologies Are More Advanced in Drosophila Than in Other Insect Species One cannot discuss the genetic manipulation of insects without describing the molecular genetic tools that are available in D. melanogaster. Traditionally, a gulf has existed between entomologists who view the harmless vinegar fly as being distant to the problems of insect control and Drosophila geneticists who utilize the many biological attributes of Drosophila to understand the basis of gene action. This gulf...

Management Of Grassland

Cutting, grazing, and burning are typical methods of grassland management. As management alters plant growth and vegetation structure profoundly, the community of associated insects will also change. The insects' responses greatly differ between functional and taxonomic groups, and consequently it is often difficult to decide which management strategy is best in the conservation of overall diversity. Closely cut (or grazed) grasslands typically have an impoverished insect fauna. This is partly...

Brain and Optic Lobes

Authors variously use the term brain either to include all neuropils located within the head capsule or, restrictively, to refer to only those neuropils (called preoral neuropils) that lie dorsal to the esophagus. These are considered to lie anterior to the mouth. Preoral neuropils are also known as the supra-esophageal ganglion, which comprises three fused ganglia the protocerebrum, deutocerebrum, and tritocerebrum. The preoral brain of the larger Hymenoptera, such as the predatory wasp Pepsis...

The Pleuston Community

The unique properties of the water surface or air water interface constitute the environment of the pleuston community. The Collembola, or springtails, are small in size, have a springing organ (furcula), and a water-repelling cuticle that enables them to be supported by and move across water surfaces. Among the true bugs, the Gerridae (water striders) and related families, the Veliidae (broad-shouldered water striders) and Hydrometridae (water measurers), are able to skate across the water....

Isoptera

The ordinal name Isoptera refers to the two pairs of straight and very similar wings that termites have as reproductive adults. The common name, of Latin origin, translates as woodworm. Termites are small and white to tan or sometimes black. They are sometimes called white ants and can be confused with true ants (Hymenoptera). However, a closer look reveals two easily observed, distinguishing features termites have straight antennae and a broad waist between the thorax and the abdomen, whereas...

Chemosensory Coding At The Periphery

In the real world, animals encounter thousands of chemicals. Most of these are meaningless, in the sense that no behavioral response is required, whereas some are critical. A sensory system thus serves two opposing functions. First, the effective sensory system must act as a filter, allowing the animal to ignore most potential stimuli so that it can concentrate on the important ones. Second, the same system must be sensitive, sometimes exquisitely sensitive, to biologically relevant stimuli and...

Defensive Behavior

Southwestern Biological Institute, Tucson Defensive behaviors are the responses of organisms to perceived threats by potential predators. The responses can be active and obvious to an outside observer, including the predator they can be subtle and difficult to observe or they can be completely inapparent. Obvious responses might include escape flight or changing to a menacing posture, a subtle response might be the freezing of a slowly moving insect, and an inapparent behavior might be the...

Role Of Amateur Entomologists

Professionalization and an improved image as scientists has been an issue for entomologists since the 19 th century. From their origin in amateur lepidopterist clubs and local societies of collectors interested in the taxonomic position of their specimens and little else, entomological societies grew into associations of applied scientists who recognized the contribution of a client base of agriculturalists but did not make a place for them or for hobbyist entomologists (amateurs) in their...

Historical Events Mediated By Insects

Finally, insects have made their mark on human cultures by influencing events that shape history, such as wars, or by changing the way societies can or cannot accomplish things. The Panama Canal was built and ultimately controlled by the United States in part because the earlier effort by France was thwarted by mosquito-borne yellow fever. As vectors of African sleeping sickness, Glossina spp. (Diptera) have made huge pieces of land in Africa uninhabitable by humans. Bubonic plague, spread by...

Learning And Host Seeking

Insect behavior is sometimes perceived as a rigid, instinctive, inherited phenomenon not subject to change. However, there is ample evidence that many insects vary their behavior depending on circumstances, and that often learning is involved. This is also true for parasitoids. Many female parasitoids respond to host stimuli more strongly after they have parasitized a host. The heightened response, which may take the form of faster host finding and or more intensive searching, may be considered...

Largescale Ecological Change Effects Of The Pleistocene

The ecological relations of extant (i.e., existing) insects are assumed to have been the same in the past as they are now if different assumptions are made, they must be explained. The drastic climatic changes since the end of the Tertiary and especially during Pleistocene glaciations profoundly FIGURE 3 Transberingian and arctoalpine disjunctions in circumpolar Noctuidae of the genus Xestia the Old World X. speciosa is represented in western North America by the subspecies aklavicensis the...

Germ Anlage Formation

The size of the germ anlage varies relative to the length of the egg. In nearly all species, the nuclei arrive at the periphery to form a blastoderm that encompasses the whole surface of the egg. In metamorphic species, such as fruit flies and honey bees, the germ anlage forms from nearly the entire blastoderm surface. However, in direct developing species (such as the grasshopper and cricket), after the formation of a uniform synctyial blastoderm, nuclei migrate and aggregate near the...

Plant Condition

Plants in a wide range of physiological conditions may be subject to colonization by borers. Although some species of borers use healthy hosts or healthy host tissues, plants that are suffering from some type of stressful condition either attract or inhibit further dispersal behavior by many other borer species. Insects that bore into tender tips and stems frequently colonize young and vigorously growing plants. Consequently, younger plants may suffer more damage than mature plants. Open wounds...

Sense Organs

Several exoskeletal structures are involved in sense perception. Various types of mechanoreceptor are involved in registering the exact position of, and deformation in, the various exoskele-tal regions and body parts, movements of surrounding objects, currents of air or water, vibrations in the substrate, and sound oscillations. Chemoreceptors are involved in registering and discerning the presence of various chemical substances these receptors can be contact chemoreceptors (taste) or olfactory...

Survey Of Insect Taxa Displaying Type I Hypermetamorphosis

Only the Mantispidae have true hypermetamorphosis. Most of the species feed on spider eggs associated with a single egg sac. The first instar either enters a previously constructed egg sac or attaches onto a female spider and enters the sac as she constructs it. Other species feed on the larvae of various aculeate Hymenoptera. Several of these are phoretic and reach the food source by attaching to the adult bee or wasp. The only lepidopteran family with hypermetamorphosis is the Epipyropidae....

Measurement Of Distance And Direction

The ability to bees to communicate distance and direction to a food source requires that the recruiting bee and the recruits be able to measure these parameters. The study of how bees do this provides an example of how the dance language gives a readout of the perception of the bees. This in turn makes possible sophisticated analyses of the mechanisms by which bees acquire the information, analyses that are vastly more difficult to perform with insects that do not report their findings in a...

Communication Of Distance And Direction In The Dance

The waggle dance of honey bees can be thought of as a miniaturized reenactment of the flight from the hive to the food source (Fig. 1). As the flight distance to the food becomes longer, the duration of the waggle portion of the dance also becomes longer. The angle that a bee flies during the flight to the food, relative to the sun azimuth (the horizontal component of the direction toward the sun), is mirrored in the angle on the comb at which the waggle portion of the dance is performed. If...

Autonomic Nervous System

The tidal flow of hemolymph, the extracardiac pulsations, heartbeat reversal, and thermoregulation all imply a very sophisticated control of circulation by the central nervous system. The central nervous system also plays a role in regulation of the respiratory system. It seems increasingly clear that the activities of circulatory and respiratory systems are coordinated by the central nervous system, perhaps to an extent not fully appreciated, but strongly implied by the tidal flow of hemolymph...

Molecular Basis Of Circadian Organization

There has been remarkable progress in the past 15 years in identifying the molecular basis of circadian clocks in a variety of organisms. In animals, much of this progress has resulted from pioneering work with the fruit fly. In 1971 the first clock gene, the period gene, was discovered in a mutagenesis screen in D. melanogaster. A decade later the gene was cloned, paving the way for studies of the gene's regulation. This work led to the discovery of several other genes in D. melanogaster that...

Mating and How Reproductive Isolation Is Achieved

Honey bees mate in flight the process has been studied in detail in A. mellifera, and involves three stages. A queen flies out when only a few days old, and drones that are flying in the area, attracted by the pheromones she produces, follow her. If a drone succeeds in clasping the queen with his legs, FIGURE 1 Worker honey bees (Apis mellifera) on honeycomb. (Photograph courtesy of P. Kirk Visscher.) FIGURE 1 Worker honey bees (Apis mellifera) on honeycomb. (Photograph courtesy of P. Kirk...

Conservation Of Speciesrich Grasslands

Insect diversity in grassland ecosystems can be best predicted by floral diversity or related characteristics of vegetation structure, especially biomass and structural heterogeneity of the plant community. Species richness of butterflies, wild bees, phytophagous beetles, true bugs, etc., was found to be positively related to the species richness of plants. However, age of the habitat as well as fragment size is known to disproportionally enhance the number of species in higher trophic levels....

Energetics

Metabolic rates during flight exceed resting values by a factor of 50 to 200, and the thoracic muscles of flying insects exhibit the highest mass-specific rates of oxygen consumption known for any locomotor muscle. Mitochondrial densities within flight muscle fibers are correspondingly high, ranging in some insects to values as high as 45 of the total muscle volume. Energy during flight is derived almost entirely from the oxidation of chemical fuels anaerobic pathways are absent from flight...

Biotechnology and Insects

Biotechnology can be broadly defined to include all practical uses of living organisms. As such, biotechnology has been practiced since the beginning of recorded history through endeavors such as fermentation of microorganisms for production of beer, selective breeding of crops, beekeeping for the production of honey, and maintenance of silkworms for the production of silk. Laboratory techniques developed within the last 20 years that enable transfer of genes from one organism to another have...

Discovery Of The Dance Language

Observers of bees had repeatedly noted that sometimes a bee in a colony will perform repeated circular movements, closely followed by other bees, but it was Karl von Frisch who firmly established the connection between these movements and recruitment, and, in the course of a long career, discovered many aspects of communication by the dance language. Von Frisch began his studies of the dance language in 1919, with the simple yet powerful approach of marking bees with paint as they fed at a...

Circulatory System

Insects have an open circulatory system. This means that the internal organs and tissues are bathed in hemolymph, which is propelled actively to all internal surfaces by specialized pumps, pressure pulses, and body movements and is directed by vessels, tubes, and diaphragms. Without such constant bathing, tissues would die. The internal organs and tissues depend on the circulatory system for the delivery of nutrients, both to carry away excretion products and as the chemical communication...

Some Explanations For Variations In Size

The size of an insect individual is determined by its genes and by the environment in which it grows. Temperature, crowding, food quantity, and food quality are examples of environmental factors that affect size, but insects may make up for such effects by compensatory feeding. The size of female insects often determines their fecundity, which may be manifested in giving birth to many small offspring or a smaller number of large ones. To be able to produce many large offspring, which may be...

The Origin Of Honey

The Bees That Produce Honey and How They Do So Certain social insects produce and store honey as a non-perishable food for use in dearth periods. The insects include all honey bees (Apis spp.) and stingless bees (Melipona and Trigona spp.) and also certain species of social wasps in South America (Nectarina) and honey ants, e.g., Melophorus inflatus in Australia. Honey-producing species whose colonies die out at the end of the active season, which are most social wasps and bumble bees (Bombus...

Types Of Color

Light by definition involves wavelengths within the visible part of the electromagnetic spectrum. For humans it consists of wavelengths ranging from approximately 400 nm (violet) to approximately 725 nm (red). Many organisms, including insects, extend this range into the near ultraviolet (300-400 nm). White light for a particular organism consists of all wavelengths visible to that organism. Colored light has an incomplete spectrum in which only some wavelengths are represented. Matter...

Implementation Methods

The observation that nonnative insects and plants could be suppressed by importing missing specialized natural enemies from their homelands led to the first successful method for practical use of biological control. This approach is called classical biological control (because it was the first deliberate, successful application of biological control as a technology), or importation biological control, or simply natural enemy introduction. After World War II, the chemical industry began the...

Foreword

I would say that creating an encyclopedia of insects was a herculean task, but I think that sells the enterprise short. After all, Hercules only had twelve labors assigned to him, and twelve years to complete them with insects, there are over 900,000 different species and many, many more stories to tell. Twelve years from now, there will likely be even more. Why, then, would anyone undertake the seemingly impossible task of compiling an encyclopedia of insects To an entomologist, the answer is...

Problems With Insect Conservation

Traditionally, most insects have been largely disregarded in conservation, on the premise that they may be secure under measures taken to conserve more charismatic taxa such as warm-blooded vertebrates. The latter are supposed widely to act as umbrellas for most or all coexisting species, but this idea is now recognized as oversimplistic, because many invertebrates are ecologically specialized and need detailed management to sustain them in the face of environmental change. However, without...

Feeding Behavior Under Natural Conditions

In the field, feeding behavior is determined to a large extent by environmental factors, although relatively few extensive studies have been carried out. Temperature has a major effect on feeding behavior, as it does on other insect activities, with FIGURE 7 Feeding is limited by temperature. Most caterpillars of G. groenlandica, living within the Arctic Circle, feed during a 2-h window when the sun is at its zenith. For most of the time, the insects bask to raise their body temperatures,...

Metabolic Functions

The fat body participates in myriad metabolic activities and functions. Absorption from hemolymph and buildup of intracellular storage nutrients in the form of lipid droplets, carbohydrate (glycogen) deposits, and protein granules during the immature stages are aimed at accumulating reserves for later stages, and primarily to serve adult activities. Fat body cells, having homeostatic functions related to metabolism, respond to nutritional and hormonal cues that regulate and modulate blood...

Beekeeping with A cerana in Movable Frame Hives

Bees of most races of A. cerana are smaller than A. mellifera they also build smaller colonies and are less productive for the beekeeper. Unlike A. mellifera, A. cerana does not collect or use propolis. A. cerana was the only hive bee in Asia until A. mellifera was introduced in the late 1800s it had been kept in traditional hives (logs, boxes, barrels, baskets, pottery) since the first or second century A.D. in China and probably from the 300s B.C. in the upper Indus basin, now in Pakistan....

What To Advertise

Aposematism is quite simply the correlation between conspicuous signals, such as bright coloration, and prey unprofitabil-ity, Candy Rowe wrote in 2001. But why should some prey become unprofitable in the first place, while others do not Unprofitability is difficult to define, and even more difficult to measure. It is certainly contextually defined, because the propensity of an animal to eat something is highly dependent on its level of hunger and its ability to use the prey for energy once...

Beetle Diversity

Although beetles share characters supporting their common evolutionary origin, remarkable variations have evolved on the beetle theme. For example, adult body size ranges from the 0.4-mm-long Nanosella fungi ptiliid feather-winged beetles of North America to the 200-mm-long Titanus giganteus ceram-bycid long-horned beetles of South America. A rough estimate based on maximum dimensions for adult length, breadth, and depth puts the disparity in volume at a factor of 2.8 X 107. Life cycles also...

Coleoptera Beetles Weevils

Family Curculionidae (Snout Beetles, Weevils) The larvae of palm weevils, several species of Rhynchophorus, also called palm worms, are widely eaten and greatly esteemed. A modern cookbook on Cameroon cuisine includes a recipe describing coconut larvae as a favorite dish offered only to good friends. The major species are Rhynchophorus palmarum in the Western Hemisphere, R. phoenicis in Africa, and R. ferrugineus and R. bilineatus in southeastern Asia, Indonesia, and the western Pacific. All of...

Ecology And Diversity Wing Arrangement

The origin of wings was followed by an explosive diversification of insect orders. Many Carboniferous insects possessed wings of approximately equivalent size, shape, and aerodynamic function that were probably limited to low-amplitude flapping. Equivalently sized fore- and hind wings persist to this day in at least seven orders. However, major differences in the sizes of meso- and metathoracic wings are evident in both contemporary fauna and fossils from the Paleozoic. With the exception of...

Economic Impact Of Galls

The majority of plant galls harm the host plant only by diverting plant resources and thus have little economic impact. The economic impacts of gallmaking insects include the benefits of fig pollination as well as some negative economic effects in the form of crop losses. Three examples of gallmaking insects with negative economic impacts are the Hessian fly (Diptera Cecidomyiidae), the grape phylloxera (Homoptera Phylloxeridae), and the oriental chestnut gall wasp (Hymenoptera Cynipidae). The...

Origins And Breadth Of Resistance

Insecticides are not considered to be mutagenic at their field application rates and are, therefore, not the causative agents of insecticide resistance. Rather they act to select favorable mutations inherent in the population to which they are applied. Some attempts to estimate the rates at which resistant mutations occur have been made. The treatment of blow flies (Lucilia cuprina) with a chemical mutagen resulted in the production of dieldrin-resistant target-site mutations in less than one...

Head

The head is a controversial area for anatomical nomenclature, but it provides some of the best examples of evolutionary trends in anatomy. Most insect morphologists believe that the head of modern insects represents the fusion of several segments that were present in an ancestral condition. However, the number of segments included in the ground plan of the insect head has been a contentious issue among morphologists for more than a century. Any argument that attempts to explain head...

Coevolution Of Consumers And Victims

We might expect predators and prey, herbivores and plants, and parasites and their hosts to evolve in an arms race, whereby the victim evolves ever greater resistance, defense, or evasion, and the consumer evolves ever greater proficiency in finding and attacking the victim. However, the coevolu-tionary dynamics may be more complex than this, because of factors such as costs of adaptation and diffuse coevolution. Considerable evidence supports the assumption that greater elaboration of a...

Interaction Of Crypsis And Other Defenses

In many insects, an organism may not rely only on crypsis for survival. There may be some secondary means of defense once crypsis has failed and the prey has been detected by a potential predator. Insects that are cryptic at a distance but conspicuous when seen close up (including the banded larvae and arctiid moths mentioned above) are often chemically protected. This type of multiple defense is also illustrated by the moth caterpillar in Fig. 1C. If the caterpillar is disturbed and begins to...

Diversity Of Exhibit Techniques

Facilities that house live insects are diverse in construction as well as in the type of sponsoring institution. To face the challenges of exhibiting small, short-lived, seasonally limited, diapausing animals with radically different life stages, major facilities rely heavily on the in-house maintenance of breeding colonies so that specimens are available year-round. Founder stock is collected from the wild or obtained through exchange or purchase from other insectaries to establish and...

Further Reading

F. (2002). Control of muscle degeneration following autotomy of a hindleg in the grasshopper, Barytettix humphreysii. J. Insect Physiol. 48, 91 102. International Bee Research Association the native pollinators have been destroyed. Since the 1950s specialized beekeeping has also been developed for the production of royal jelly, pollen, and bee venom. Each type of beekeeping requires the management of colonies to stimulate the bees to do what the beekeeper wants...

The Role Of Systematics In Biodiversity Assessment

Systematics is the part of comparative biology that tracks the diversity of organisms with regard to specified relationships among those organisms. It is the branch of biology responsible for recognizing, comparing, classifying, and naming the millions of different sorts of organism that exist. Taxonomy is the theory and practice of describing the diversity of organisms and the arrangement of these organisms into classifications. Widely accepted as the most basic of natural taxa is the species....

Types Of Industrial Melanism

Three categories of industrial melanism have been recognized A. Full industrial melanic polymorphism involves distinct melanic forms that have arisen since the industrial revolution and have increased as a consequence of the effects of industrialization on the environment. B. Partial industrial melanic polymorphism involves polymorphic species that had melanic forms prior to the industrial revolution. These forms have increased in frequency following and as a consequence of the effects of...

Transgenic Plants

A recent development in crop protection has been the release of crop plants genetically engineered to express genes for insecticidal toxins derived from the microbe B. thuringiensis. In 2001 the total area worldwide planted to Bt plants was estimated to exceed 12 million ha. Existing toxin genes in Bt cotton and corn are active specifically against certain key lepidopteran pests (especially bollworms and corn borers) another engineered into potatoes provides protection against the Colorado...

Pleural Regions Of The Thorax

Apterygota and Immature Plecoptera The anapleurite is the sclerotized area above the coxa (supracoxal area) (Fig. 8). The coxopleurite is a sclerotized plate situated between the coxa and the anapleurite (Fig. 8). It bears the dorsal coxal articulation, the anterior part of which becomes the definitive trochantin. The sternopleurite, or coxosternite, is the definitive sternal sclerite that includes the areas of the limb bases and is situated beneath the coxa (Fig. 8). Pterygota The basalare is...

State Regional And County Organization

Organizational structure of the Cooperative Extension Services varies greatly in size from state to state. In general, leadership of Cooperative Extension Services within each state is the responsibility of the dean and or director of the agricultural college of the land-grant university and or 1890 institution within each state. These directors provide leadership to an administrative staff that often includes associate and or assistant deans of extension, directors of county operations,...

Larval Development The Intermolt

Because the exoskeleton places limits on growth, insect development occurs in stages, each ending with molting and cuticle shedding, or ecdysis. During the intermolt, which follows ecdysis, JH levels are maintained around 1 to 10 ng ml in the blood (Fig. 2). It is presumed that these JH levels promote a high metabolic rate, active feeding behavior, synthesis of larval cuticle proteins, and continuous proliferation (but not differentiation) of imaginal discs. Growth during the immature stages is...

Effects Of Changed Plant Chemistry On Insect Densities And Mortalities

There has been relatively little research into how CO2-mediated changes in plant chemistry affect insect densities and mortalities. This is because most plant insect work has been done in laboratory conditions, where insects are fed foliage grown in elevated or ambient CO2 and insect weight gains, losses, and digestibility coefficients are measured. To predict the effects of elevated CO2 on insect densities, a population must be established on CO2-treated foliage. However, in the few cases...

Anatomical Specializations For Insectivory

Although eating insects is a dominant part of many diets, anatomical and behavioral specializations for insectivory are not as widespread. Many lizards, for example, feed on whatever suitable prey item might be available. Nevertheless, there are several anatomical specializations that seem to assist in the capture of insect prey. Perhaps the most obvious and remarkable trait is a highly projectile tongue. This sort of tongue evolved many times, in many different lineages, and in many different...

The Benthos Community

Benthos, derived from the Greek word for bottom, refers to the fauna associated with the solid water interface and includes insects residing on the bottom or associated with plant surfaces, logs, rocks, and other solid substrates. In lentic habitats, many insects fall into this category as mentioned earlier, particularly the Chironomidae, which often represent over 90 of the fauna in the profundal (deep-water) zone of lakes and ponds. These inhabitants are mostly burrowers that feed on...

Mechanisms Of Action Of Insecticides

The great majority of insecticides used today are nerve poisons. This is because insects have highly developed nervous systems and, furthermore, many of their sensory receptors are exposed to the atmosphere outside the insect body. The insect nervous system relies on several key functions that have been exploited as the targets of insecticides the sodium channel, acetylcholinesterase, the y-aminobutyric acid (GABA) receptor, and the acetylcholine receptor. The sodium channel, which is the...

Ecosystemlevel Patterns

Worldwide there are about 4000 species of scarabaeine dung beetles. Local species richness is generally related to the species richness of large mammalian grazing animals, although cattle dung does support a rich dung beetle fauna around the world. The most competitive assemblages of dung beetles occur in tropical grasslands, where up to 120 species can be present in local areas here, competition for the dung resource is high. Intraspecific competition for dung occurs in a range of beetle...

Apis Species

International Bee Research Association Honey bees (genus Apis) are social insects in the family Apidae, order Hymenoptera they are among the Aculeata (i.e., those having stingers). They evolved after the separation of the Americas and Australia from Eurasia Africa and are native only in the Old World. The genus Apis probably first appeared in the Eocene, about 55 mya. Tropical species A. dorsata and A. florea existed by the end of the Oligocene 25 mya, and cavity-nesting A. mellifera and A....

Nonsalivary Entangling Secretions

The posterior abdominal tergites and cerci of cockroaches in a variety of genera are covered with a viscous secretion that can act as an entangling glue for small predators. Species in genera as diverse as Blatta and Pseudoderopeltis produce proteinaceous secretions on the abdominal tergites that would be readily encountered by predators pursuing these cockroaches. After seizing the cockroaches, predatory centipedes, beetles, and ants rapidly release their prey while cleaning their mouthparts....

Vi

FIGURE 7 Male genitalia of a ditrysian moth (Tortricidae), venterolateral aspect with valvae reflexed. un, uncus tg, tegumen so, socii gn, gnathos tr, transtilla ju, juxta va, valva sa, sacculus vi, vinculum ph, phallus (aedeagus) ve, vesica co, cornuti. visible part of the genitalia externally. The phallus, which is separately articulated and passes through the diaphragma, is sclerotized and contains the membranous vesica, the intro-mittent organ. The vesica often is armed with cornuti, which...

Gut Morphology And Function

Figure 1 is a generalized diagram of the insect gut. The foregut begins at the mouth, includes the cibarium (preoral cavity formed by mouthparts), the pharynx, the esophagus, and the crop (a dilated portion, as in Fig. 2A, or a diverticulum, like Fig. 2K). The crop is a storage organ in many insects and also serves as a site for digestion in others. The foregut is lined by a cuticle that is nonpermeable to hydrophilic molecules and in some insects is reduced to a straight tube (Fig. 2F). The...

Egg Coverings

The protective coverings females provide their eggs reflect the full range of environments exploited by insects. Egg coverings fall into two major categories those produced by follicle cells and those produced by accessory glands of the reproductive tract. Follicle cells secrete the chorion, or insect eggshell. The design of the chorion is important in fertilization, egg respiration, and water balance. Coverings produced by accessory glands provide additional protection from the elements,...

Decomposition

Although there have been many decomposition studies conducted in different parts of the world and under different environmental conditions, most studies have been conducted in temperate areas and fewer in tropical and subtropical habitats. Common to the majority of these studies has been an attempt to divide the decompositional process into a series of discrete stages. Decomposition is, in nature, a continuous process and so discrete combinations of physical parameters and arthropod assemblages...

Chromosomal Rearrangements

Rearrangements occur in the chromosomes of insects when they occasionally break and rejoin in an irregular fashion. If any chromosomal rearrangement is maintained heterozygously in a population at a frequency greater than can be explained by recurrent chromosomal mutation, it is said to be polymorphic. There are a number of chromosomal rearrangements. Paracentric inversions result when two breaks in one chromosome arm rejoin after the excised piece has inverted. These rearrangements are...

Division Of Labor

The relatively large biomass of ants in many ecosystems can be attributed not just to the way in which the ants interact with other organisms but to the way in which they interact with their nestmates in general and, in particular, to efficiencies that accrue from divisions of labor. One of the most dramatic traits associated with the division of labor among the workers is physical polymorphism, which is the presence of different physical worker forms within the same colony. In the African army...

Origination and World Spread of Movable Frame Beekeeping

The production of a movable-frame hive divided the history of hive beekeeping into two distinct phases. This new hive type was invented in 1851 by Reverend Lorenzo Lorraine Langstroth in Philadelphia. He was familiar with the Greek movable-comb hive (discussed later under Traditional Movable-Comb Hive Beekeeping) and with some rectangular hives devised in Europe that contained wooden frames for the bees to build their combs in. These hives, however, had only a very small gap between the frames...

The Blood Meal

Blood-sucking insects take huge meals. Temporary ectoparasites such as the tsetse fly typically ingest more than their own unfed body weight in blood. The reasons are twofold. First, taking a blood meal is a very dangerous activity and taking huge blood meals minimizes the number of times an insect must associate with the host. Second, locating the host is often difficult and huge blood meals are a way of making the most of each encounter. Mouthparts are adapted to the blood-feeding habit....

Anatomy Of Emission

The ultrastructure of the flashing lantern was first seen in the 1960s, when the electron microscope revealed that a miniature and new type of structure, the tracheal end organ, occurred throughout the flashing lantern, and that each microunit was obviously involved in controlling the photocytes associated with it. The light-emitting layer of a flashing lantern is organized into a sheet of rosettes, each with a central channel (cylinder), through which air-supply tubes and nerve trunks pass,...

Thermoregulation

Before the extracardiac pulsations were reported and before the tidal flow of hemolymph had been described in insects, Bernd Heinrich wrote about the use of the hemolymph in thermoregulation of flying insects. The optimum temperature for flight muscle contraction in many insects, such as the tobacco hornworm, Manduca sexta, is surprisingly high, up to 45 C. Before this moth can fly, it must warm the thorax to near this temperature, which it accomplishes by means of a series of simultaneous...

Fossil Record And Evolution

A widely accepted phylogenetic hypothesis of relationships among lepidopteran evolutionary lineages, based on morphological characteristics in living forms, primarily of the adults, is shown in Fig. 1. The problem in such analysis is that we do not know what kinds of species might have preceded and interceded with the primitive extant lineages, each of which is now represented by one or a few relict genera that have divergent larval features not shared with other Lepidoptera. Moreover, the...

Honeydew As Food

Many insects in several orders, including Diptera, Hymen-optera, Lepidoptera, Coleoptera, and Neuroptera, feed on honeydew that has fallen onto plant or other surfaces. Among these insects are herbivores (e.g., tephritid flies, butterflies, and moths) and many entomophagous taxa, such as chrysopids, coccinellids, syrphids, tachinid flies, and hymenopteran parasitoids. A number of nectivorous birds in Mexico and Australia forage on honeydew and lerp lerp is also consumed by flying foxes in...

Molecular Circuits That Regulate Segmentation

In the cascade of gene activity that generates the segmental pattern of the embryo (Fig. 2), segmentation proceeds by a progressive refinement of positional information that will eventually specify groups of cells that form metameric units. Refinement is initiated with maternally provided proteins that form gradients from the anterior to the posterior of the egg and early cleavage stages. These gradients of maternal proteins provide the coordinates that position the front and FIGURE 3 Double...

Historical Development

Biological control is the deliberate attempt by people to make practical use of the capacity of predation, parasitism, herbivory, and disease to restrain the growth of plant and animal populations. The ability to make practical use of these processes depends on an understanding of how pest population densities are controlled by natural enemies. Biological control also requires detailed knowledge of the biology of pests and their key natural enemies, because such knowledge often provides the...

Active Traps

Plants with rapid movement usually first come to mind when carnivorous plants are mentioned. These so-called active traps imprison their prey by a quick movement of all or part of the leaf. Into this group are placed several genera one well known, the Venus flytrap (Dionaea) (Fig. 3) and the others less familiar (e.g., the bladderworts, Utricularia) (Fig. 4). It is believed that the rapid movement comes about when the prey makes contact with a triggering mechanism, resulting in the generation...

Why There Are So Many Bacillus Thuringiensis Plants

The first commercial transgenic crops were planted in China during the early 1990s. These were primarily virus-resistant tobacco and tomato. In the United States, the first commercialized crop was Calgene's FLVR SAVR tomato in 1994. This product was not a commercial success in part because it did not pack well for shipping. Initially, a variety of transgenic crops were planted (Table Ia) by 1999, however, four crops dominated soybean, corn, cotton, and canola. The primary traits of these GM...

Circadian Rhythms

Circadian rhythms are daily oscillations in physiology, metabolism, or behavior that persist (or free run) in organisms that have been isolated from periodic fluctuations in the environment. These rhythms are under the control of innate regulatory systems that are based on internal oscillators (or pacemakers) whose periods approximate those of the naturally recurring 24-h environmental cycles. The oscillators are subject to control by a limited number of these environmental cycles that...

Conclusions

Hyperparasitism intrigues entomologists because of its multidisciplinary relationship to evolution, ecology, behavior, biological control, taxonomy, and mathematical models. More field studies are needed to determine whether hyperparasitoids are always detrimental to biological control programs. Perhaps, instead, they could have a beneficial influence by regulating the extreme detrimental population oscillations of the beneficial primary parasitoids. Godfray, H. C. J. (1994). Parasitoids...

Life Cycle

Japanese beetles have a one-year life cycle in most parts of their range. Adults occur from June to August. Upon emergence FIGURE 1 (A) Japanese beetles with characteristic feeding damage. (B) Japanese beetle grub. FIGURE 1 (A) Japanese beetles with characteristic feeding damage. (B) Japanese beetle grub. from the soil, virgin females emit a volatile sex pheromone that attracts clusters of males. Subsequent matings occur on food plants. The beetles typically feed from the upper surface of...

Potential Adverse Effects

The risks associated with transgenic plants stem from, but are not directly caused by, the nature of the transformation process. First, transgenic methods enable traits to be expressed that have never before been expressed in a plant. This widened range of traits creates potential risks that should be evaluated. Second, the present transgenic methods cannot incorporate foreign DNA into precise locations in the plant genome. Because expression of genes can depend on where the gene occurs in the...

Auchenorrhyncha

(Cicadas, Spittlebugs, Leafhoppers, Treehoppers, and Planthoppers) The hemipteran suborder Auchenorrhyncha is the group of sapsucking insects comprising the modern superfamilies, Cercopoidea (spittlebugs, Fig. 1), Cicadoidea (cicadas, Fig. 2), Membracoidea (leafhoppers and treehoppers, Fig. 3), and Fulgoroidea (Fig. 4) Together, these groups include over 40,000 described species. Morphologically, Auchenorrhyncha differ from other Hemiptera in having the antennal flagellum FIGURE 1 Cercopoidea...

Abc

FIGURE 8 Three mechanisms of dark adaptation in apposition eyes of insects (see text). (Reproduced, with permission, from Land and Nilsson, 2002.) FIGURE 8 Three mechanisms of dark adaptation in apposition eyes of insects (see text). (Reproduced, with permission, from Land and Nilsson, 2002.) this is to absorb the wave-guided light that travels just outside the rhabdom. This is replaced with light within the rhabdom, and this is absorbed in turn, so that light is progressively bled out of the...

Culture And Literature

The Aztecs combined science and humanities with a firefly 'A firefly in the night' the Nahuas called their songs a tiny light in a great darkness, a little truth within the ignorance surrounding them. It is a culturally impoverished American who has not heard of Wah-wah-taysee, the firefly in a memorized passage from Longfellow's Song of Hiawatha or does not know where to find reference to a glowworm in Hamlet, or what Robert Frost said about fireflies, or what a glowworm did for the Mills...

Insectderived Tools Used For Biotechnological Research

Expression of Foreign Proteins in Insect Cells Production of large amounts of a particular protein is extremely valuable for both research and industrial purposes. Baculoviruses, which are double-stranded DNA viruses that infect mainly insects, have been developed as baculovirus expression vectors (BEVs) by genetic modification to include a gene of interest. BEVs can replicate in lepidopteran cells and larvae, thereby efficiently transferring foreign genes into eukaryotic cells. The foreign...

Genetic Engineering In Nondrosophilid Insects

Genetic Transformation of Nondrosophilid Insects The P element paradigm is successful in nondrosophilid insects. Despite many attempts, the P element was found to be unusable as a gene vector in nondrosophilid insect species. The reason for the narrow host range of P is unknown however, it has been proposed that P is dependent for its mobility, in part, on the presence of host-encoded factors. These are thought to be absent, or at least sufficiently diverged, to prevent the mobility of P in...

Aphid Complex

Over many decades, studies of hyperparasitism have been conducted on the primary parasitoid microwasps in the Hymenoptera that attack the Hemiptera in the suborder Sternorrhyncha, and in particular the superfamily Aphidoidea, with special emphasis on the family Aphididae. The aphid-primary parasitoid-hyperparasitoid food web has been used as a model system in community ecology partly because of the economic importance of aphids as worldwide pests on a variety of agricultural crops and forests,...