61-564: Ceratitis is a genus of tephritid fruit flies with about 80 species. One of the best known species is Ceratitis capitata , the Mediterranean fruit fly. The genus contains several subgenera: (see some as alternative spelling Ceratitis munroanum , elsewhere as protonym Acropteromma munroanum ) (for Ceratitis pycnanthi (Ghesquière, 1942) see as synonym under Ceratitis striatella per Meyer, 1998 ) (note for Ceratitis antistictica see subgenus Ceratalaspis ). On
122-523: A decrease in abundance of leaf-chewing larvae in the fall when hardwood leaf palatability decreases due to increased tannin levels which results in a decline of arthropod species richness , and increased palatability of plant communities at higher elevations where grasshoppers abundances are lower. Climatic stressors such as ocean acidification can lead to responses in plant-herbivore interactions in relation to palatability as well. The myriad defenses displayed by plants means that their herbivores need
183-400: A dorsal preapical bristle. The female has an oviscape. The larva is amphipneustic (having only the anterior and posterior pairs of spiracle). The body varies from white to yellowish or brown. The posterior end of pale-coloured species is sometimes black. The body tapers at the anterior. The two mandibles sometimes have teeth along the ventral margin. The antennomaxillary lobes at each side of
244-623: A greater and more diverse set of resources. Coevolution and phylogenetic correlation between herbivores and plants are important aspects of the influence of herbivore and plant interactions on communities and ecosystem functioning, especially in regard to herbivorous insects. This is apparent in the adaptations plants develop to tolerate and/or defend from insect herbivory and the responses of herbivores to overcome these adaptations. The evolution of antagonistic and mutualistic plant-herbivore interactions are not mutually exclusive and may co-occur. Plant phylogeny has been found to facilitate
305-465: A herbivore in a dense forest would spend more time handling (eating) the vegetation because there was so much vegetation around than a herbivore in a sparse forest, who could easily browse through the forest vegetation. According to the Holling's disk equation, a herbivore in the sparse forest would be more efficient at eating than the herbivore in the dense forest. The marginal value theorem describes
366-458: A humeral and a subcostal break. The apical part of the subcostal is usually indistinct or even transparent and at about a right angle with respect to the basal part. Crossvein BM-Cu is present; the cell cup (posterior cubital cell or anal cell) is closed and nearly always narrowing to an acute angle. It is closed by a geniculated vein (CuA2). The CuA2 vein is rarely straight or convex. The tibiae lack
427-495: A mutual relationship with the plant species that they forage by digging and disturbing the sediment which removes competing plants and subsequently allows colonization of other plant species. When herbivores are affected by trophic cascades , plant communities can be indirectly affected. Often these effects are felt when predator populations decline and herbivore populations are no longer limited, which leads to intense herbivore foraging which can suppress plant communities. With
488-557: A new patch of food when the patch they are currently feeding on requires more energy to obtain food than an average patch. Within this theory, two subsequent parameters emerge, the Giving Up Density (GUD) and the Giving Up Time (GUT). The Giving Up Density (GUD) quantifies the amount of food that remains in a patch when a forager moves to a new patch. The Giving Up Time (GUT) is used when an animal continuously assesses
549-595: A pest of sunflowers and Rhagoletis mendax , a pest of blueberries. Another notorious agricultural pest is the Mediterranean fruit fly or Medfly, Ceratitis capitata , which is responsible for millions of dollars' worth in expenses by countries for control and eradication efforts, in addition to costs of damage to fruit crops. Similarly, the Queensland fruit fly ( Bactrocera tryoni ) is responsible for more than $ 28.5 million in damage to Australian fruit crops
610-715: A result of their plant-based diet, herbivorous animals typically have mouth structures ( jaws or mouthparts ) well adapted to mechanically break down plant materials, and their digestive systems have special enzymes (e.g. amylase and cellulase ) to digest polysaccharides . Grazing herbivores such as horses and cattles have wide flat- crowned teeth that are better adapted for grinding grass , tree bark and other tougher lignin -containing materials, and many of them evolved rumination or cecotropic behaviors to better extract nutrients from plants. A large percentage of herbivores also have mutualistic gut flora made up of bacteria and protozoans that help to degrade
671-635: A single plant can have hundreds of different chemical defenses. Chemical defenses can be divided into two main groups, carbon-based defenses and nitrogen-based defenses. Plants have also changed features that enhance the probability of attracting natural enemies to herbivores. Some emit semiochemicals, odors that attract natural enemies, while others provide food and housing to maintain the natural enemies' presence, e.g. ants that reduce herbivory. A given plant species often has many types of defensive mechanisms, mechanical or chemical, constitutive or induced, which allow it to escape from herbivores. According to
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#1732802033449732-574: A terrestrial mammal to be called a grazer, at least 90% of the forage has to be grass, and for a browser at least 90% tree leaves and twigs. An intermediate feeding strategy is called "mixed-feeding". In their daily need to take up energy from forage, herbivores of different body mass may be selective in choosing their food. "Selective" means that herbivores may choose their forage source depending on, e.g., season or food availability, but also that they may choose high quality (and consequently highly nutritious) forage before lower quality. The latter especially
793-399: A tradeoff however, between foraging on many plant species to avoid toxins or specializing on one type of plant that can be detoxified. Herbivore modification is when various adaptations to body or digestive systems of the herbivore allow them to overcome plant defenses. This might include detoxifying secondary metabolites , sequestering toxins unaltered, or avoiding toxins, such as through
854-438: A trophic cascade involved plant-herbivore interactions are coral reef ecosystems. Herbivorous fish and marine animals are important algae and seaweed grazers, and in the absence of plant-eating fish, corals are outcompeted and seaweeds deprive corals of sunlight. Agricultural crop damage by the same species totals approximately $ 100 million every year. Insect crop damages also contribute largely to annual crop losses in
915-579: A variety of physical and metabolic alterations in the way the host plant interacts with itself and other surrounding biotic factors. Fungi, bacteria, and protists that feed on living plants are usually termed plant pathogens (plant diseases), while fungi and microbes that feed on dead plants are described as saprotrophs . Flowering plants that obtain nutrition from other living plants are usually termed parasitic plants . There is, however, no single exclusive and definitive ecological classification of consumption patterns; each textbook has its own variations on
976-527: A variety of skills to overcome these defenses and obtain food. These allow herbivores to increase their feeding and use of a host plant. Herbivores have three primary strategies for dealing with plant defenses: choice, herbivore modification, and plant modification. Feeding choice involves which plants a herbivore chooses to consume. It has been suggested that many herbivores feed on a variety of plants to balance their nutrient uptake and to avoid consuming too much of any one type of defensive chemical. This involves
1037-400: A year. This species lays eggs in a wide variety of unripe fruit hosts, causing them to rot prior to ripening. Some fruit flies are used as agents of biological control , thereby reducing the populations of pest species. Several species of the genus Urophora are used as control agents against rangeland-destroying noxious weeds such as starthistles and knapweeds , but their effectiveness
1098-460: Is a model for predicting animal behavior while looking for food or other resources, such as shelter or water. This model assesses both individual movement, such as animal behavior while looking for food, and distribution within a habitat, such as dynamics at the population and community level. For example, the model would be used to look at the browsing behavior of a deer while looking for food, as well as that deer's specific location and movement within
1159-403: Is aided in reproduction. Plants can also be indirectly affected by herbivores through nutrient recycling , with plants benefiting from herbivores when nutrients are recycled very efficiently. Another form of plant-herbivore mutualism is physical changes to the environment and/or plant community structure by herbivores which serve as ecosystem engineers , such as wallowing by bison. Swans form
1220-431: Is derived from Latin herba 'small plant, herb' and vora , from vorare 'to eat, devour'. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants , algae and photosynthesizing bacteria . More generally, organisms that feed on autotrophs in general are known as primary consumers . Herbivory is usually limited to animals that eat plants. Insect herbivory can cause
1281-563: Is determined by the body mass of the herbivore, with small herbivores selecting for high-quality forage, and with increasing body mass animals are less selective. Several theories attempt to explain and quantify the relationship between animals and their food, such as Kleiber's law , Holling's disk equation and the marginal value theorem (see below). Kleiber's law describes the relationship between an animal's size and its feeding strategy, saying that larger animals need to eat less food per unit weight than smaller animals. Kleiber's law states that
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#17328020334491342-655: Is divided into several subfamilies: The genera Oxyphora , Pseudorellia , and Stylia comprise 32 species, and are not included in any subfamily ( incertae sedis ). Phytophagy A herbivore is an animal anatomically and physiologically evolved to feed on plants , especially upon vascular tissues such as foliage , fruits or seeds , as the main component of its diet . These more broadly also encompass animals that eat non-vascular autotrophs such as mosses , algae and lichens , but do not include those feeding on decomposed plant matters (i.e. detritivores ) or macrofungi (i.e. fungivores ). As
1403-783: Is irrelevant and derived to explain trends that do not exist in nature. Holling's disk equation models the efficiency at which predators consume prey. The model predicts that as the number of prey increases, the amount of time predators spend handling prey also increases, and therefore the efficiency of the predator decreases. In 1959, S. Holling proposed an equation to model the rate of return for an optimal diet: Rate (R )=Energy gained in foraging (Ef)/(time searching (Ts) + time handling (Th)) R = E f / ( T s + T h ) {\displaystyle R=Ef/(Ts+Th)} Where s=cost of search per unit time f=rate of encounter with items, h=handling time, e=energy gained per encounter. In effect, this would indicate that
1464-419: Is of great interest to biologists. Some fruit flies have extensive mating rituals or territorial displays. Many are brightly colored and visually showy. Some fruit flies show Batesian mimicry , bearing the colors and markings of dangerous arthropods such as wasps or jumping spiders because it helps the fruit flies avoid predation, though the flies lack stingers . Adult tephritid fruit flies are often found on
1525-686: Is questionable. Urophora sirunaseva produces larvae that pupate within a woody gall within the flower and disrupt seed production. Chaetorellia acrolophi is an effective biocontrol agent against knapweeds Chaetorellia australis and Chaetorellia succinea , deposit eggs into the starthistle seedheads, where their larvae consume the seeds and flower ovaries. Since economically important tephritid fruit flies exist worldwide, vast networks of researchers, several international symposia, and intensive activities on various subjects extend from ecology to molecular biology ( Tephritid Workers Database ). Pest management techniques applied to tephritid include
1586-488: Is the ability of a plant to withstand damage without a reduction in fitness. This can occur by diverting herbivory to non-essential plant parts, resource allocation, compensatory growth, or by rapid regrowth and recovery from herbivory. Resistance refers to the ability of a plant to reduce the amount of damage it receives from herbivores. This can occur via avoidance in space or time, physical defenses, or chemical defenses. Defenses can either be constitutive, always present in
1647-577: The UF / IFAS Featured Creatures Web site Tephritidae The Tephritidae are one of two fly families referred to as fruit flies , the other family being the Drosophilidae . The family Tephritidae does not include the biological model organisms of the genus Drosophila (in the family Drosophilidae), which is often called the "common fruit fly". Nearly 5,000 described species of tephritid fruit fly are categorized in almost 500 genera of
1708-491: The cellulose in plants, whose heavily cross-linking polymer structure makes it far more difficult to digest than the protein - and fat -rich animal tissues that carnivores eat. Herbivore is the anglicized form of a modern Latin coinage, herbivora , cited in Charles Lyell 's 1830 Principles of Geology . Richard Owen employed the anglicized term in an 1854 work on fossil teeth and skeletons. Herbivora
1769-596: The larvae find their food upon emerging. The larvae develop in leaves , stems, flowers, seeds, fruits, and roots of the host plant, depending on the species. Some species are gall-forming . One exception to the phytophagous lifestyle is Euphranta toxoneura (Loew) whose larvae develop in galls formed by sawflies . The adults sometimes have a very short lifespan. Some live for less than a week. Some species are monophagous (feeding on only one plant species) others are polyphagous (feeding on several, usually related plant species). The behavioral ecology of tephritid fruit flies
1830-432: The wetland ecosystem . Such differences in herbivore modalities can potentially lead to trade-offs that influence species traits and may lead to additive effects on community composition and ecosystem functioning. Seasonal changes and environmental gradients such as elevation and latitude often affect the palatability of plants which in turn influences herbivore community assemblages and vice versa. Examples include
1891-762: The Tephritidae. Description , recategorization , and genetic analyses are constantly changing the taxonomy of this family. To distinguish them from the Drosophilidae, the Tephritidae are sometimes called peacock flies , in reference to their elaborate and colorful markings. The name comes from the Greek τεφρος, tephros , meaning "ash grey". They are found in all the biogeographic realms . For terms see Morphology of Diptera and Tephritidae glossary Tephritids are small to medium-sized (2.5–10 mm) flies that are often colourful, and usually with pictured wings,
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1952-515: The U.S. Herbivores also affect economics through the revenue generated by hunting and ecotourism. For example, the hunting of herbivorous game species such as white-tailed deer, cottontail rabbits, antelope, and elk in the U.S. contributes greatly to the billion-dollar annually, hunting industry. Ecotourism is a major source of revenue, particularly in Africa, where many large mammalian herbivores such as elephants, zebras, and giraffes help to bring in
2013-416: The balance between eating all the food in a patch for immediate energy, or moving to a new patch and leaving the plants in the first patch to regenerate for future use. The theory predicts that absent complicating factors, an animal should leave a resource patch when the rate of payoff (amount of food) falls below the average rate of payoff for the entire area. According to this theory, an animal should move to
2074-824: The colonization and community assembly of herbivores, and there is evidence of phylogenetic linkage between plant beta diversity and phylogenetic beta diversity of insect clades such as butterflies . These types of eco-evolutionary feedbacks between plants and herbivores are likely the main driving force behind plant and herbivore diversity. Abiotic factors such as climate and biogeographical features also impact plant-herbivore communities and interactions. For example, in temperate freshwater wetlands herbivorous waterfowl communities change according to season, with species that eat above-ground vegetation being abundant during summer, and species that forage below-ground being present in winter months. These seasonal herbivore communities differ in both their assemblage and functions within
2135-424: The effectiveness of plant defenses activated by sunlight. A plant defense is a trait that increases plant fitness when faced with herbivory. This is measured relative to another plant that lacks the defensive trait. Plant defenses increase survival and/or reproduction (fitness) of plants under pressure of predation from herbivores. Defense can be divided into two main categories, tolerance and resistance. Tolerance
2196-538: The end of that period. Herbivory among four-limbed terrestrial vertebrates, the tetrapods , developed in the Late Carboniferous (307–299 million years ago). The oldest known example being Desmatodon hesperis. Early tetrapods were large amphibious piscivores . While amphibians continued to feed on fish and insects, some reptiles began exploring two new food types, tetrapods (carnivory) and plants (herbivory). The entire dinosaur order ornithischia
2257-493: The first land plants evolved. Insects fed on the spores of early Devonian plants, and the Rhynie chert also provides evidence that organisms fed on plants using a "pierce and suck" technique. During the next 75 million years , plants evolved a range of more complex organs, such as roots and seeds. There is no evidence of any organism being fed upon until the middle-late Mississippian , 330.9 million years ago . There
2318-596: The food chain because they consume plants to digest the carbohydrates photosynthetically produced by a plant. Carnivores in turn consume herbivores for the same reason, while omnivores can obtain their nutrients from either plants or animals. Due to a herbivore's ability to survive solely on tough and fibrous plant matter, they are termed the primary consumers in the food cycle (chain). Herbivory, carnivory, and omnivory can be regarded as special cases of consumer–resource interactions . Two herbivore feeding strategies are grazing (e.g. cows) and browsing (e.g. moose). For
2379-565: The food source, in this case, the plant. Several factors play into these fluctuating populations and help stabilize predator-prey dynamics. For example, spatial heterogeneity is maintained, which means there will always be pockets of plants not found by herbivores. This stabilizing dynamic plays an especially important role for specialist herbivores that feed on one species of plant and prevents these specialists from wiping out their food source. Prey defenses also help stabilize predator-prey dynamics, and for more information on these relationships see
2440-426: The forested habitat and its interaction with other deer while in that habitat. This model has been criticized as circular and untestable. Critics have pointed out that its proponents use examples that fit the theory, but do not use the model when it does not fit the reality. Other critics point out that animals do not have the ability to assess and maximize their potential gains, therefore the optimal foraging theory
2501-832: The fossil record of their jaws near the Permio-Carboniferous boundary, approximately 300 million years ago. The earliest evidence of their herbivory has been attributed to dental occlusion , the process in which teeth from the upper jaw come in contact with teeth in the lower jaw is present. The evolution of dental occlusion led to a drastic increase in plant food processing and provides evidence about feeding strategies based on tooth wear patterns. Examination of phylogenetic frameworks of tooth and jaw morphologes has revealed that dental occlusion developed independently in several lineages tetrapod herbivores. This suggests that evolution and spread occurred simultaneously within various lineages. Herbivores form an important link in
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2562-405: The frontal bristles are inserted on a raised tubercle. Interfrontal setulae are usually absent or represented by one or two tiny setulae near the lunula. True vibrissae are absent, but several genera have strong bristles near the vibrissal angle. The wings usually have yellow, brown, or black markings or are dark-coloured with lighter markings. In a few species, the wings are clear. The costa has both
2623-532: The host plant and feeding on pollen, nectar, rotting plant debris, or honeydew. Natural enemies include parasitoid wasps of the genera Diapriidae and Braconidae . Tephritid fruit flies are of major economic importance in agriculture . Some have negative effects, some positive. Various species of fruit flies cause damage to fruit and other plant crops. The genus Bactrocera is of worldwide notoriety for its destructive impact on agriculture. The olive fruit fly ( B. oleae ), for example, feeds on only one plant:
2684-430: The incorporation of silica into cell walls is analogous to that of the role of lignin in that it is a compression-resistant structural component of cell walls; so that plants with their cell walls impregnated with silica are thereby afforded a measure of protection against herbivory. Chemical defenses are secondary metabolites produced by the plant that deter herbivory. There are a wide variety of these in nature and
2745-406: The interaction of herbivory and plant defense is negative, with one individual reducing the fitness of the other, some is beneficial. This beneficial herbivory takes the form of mutualisms in which both partners benefit in some way from the interaction. Seed dispersal by herbivores and pollination are two forms of mutualistic herbivory in which the herbivore receives a food resource and the plant
2806-677: The mandibles have several transverse oral ridges or short laminae directed posteriorly. The anterior spiracles (prothoracic spiracles) end bluntly and are not elongated. Each has at least three openings or up to 50 arranged transversely in one to three groups or irregularly. Each posterior spiracle (anal spiracle) lacks a clearly defined peritreme and each has three spiracular openings (in mature larvae). These are usually more or less horizontal, parallel and usually bear branched spiracular hairs in four tufts. The larvae of almost all Tephritidae are phytophagous . Females deposit eggs in living, healthy plant tissue using their telescopic ovipositors . Here,
2867-407: The metabolic rate (q 0 ) of an animal is the mass of the animal (M) raised to the 3/4 power: q 0 =M Therefore, the mass of the animal increases at a faster rate than the metabolic rate. Herbivores employ numerous types of feeding strategies. Many herbivores do not fall into one specific feeding strategy, but employ several strategies and eat a variety of plant parts. Optimal foraging theory
2928-402: The patch quality. Interactions between plants and herbivores can play a prevalent role in ecosystem dynamics such community structure and functional processes. Plant diversity and distribution is often driven by herbivory, and it is likely that trade-offs between plant competitiveness and defensiveness , and between colonization and mortality allow for coexistence between species in
2989-570: The plant, or induced, produced or translocated by the plant following damage or stress. Physical, or mechanical, defenses are barriers or structures designed to deter herbivores or reduce intake rates, lowering overall herbivory. Thorns such as those found on roses or acacia trees are one example, as are the spines on a cactus. Smaller hairs known as trichomes may cover leaves or stems and are especially effective against invertebrate herbivores. In addition, some plants have waxes or resins that alter their texture, making them difficult to eat. Also
3050-538: The presence of herbivores. However, the effects of herbivory on plant diversity and richness is variable. For example, increased abundance of herbivores such as deer decrease plant diversity and species richness , while other large mammalian herbivores like bison control dominant species which allows other species to flourish. Plant-herbivore interactions can also operate so that plant communities mediate herbivore communities. Plant communities that are more diverse typically sustain greater herbivore richness by providing
3111-403: The production of large amounts of saliva to reduce effectiveness of defenses. Herbivores may also utilize symbionts to evade plant defenses. For example, some aphids use bacteria in their gut to provide essential amino acids lacking in their sap diet. Plant modification occurs when herbivores manipulate their plant prey to increase feeding. For example, some caterpillars roll leaves to reduce
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#17328020334493172-490: The section on Plant Defenses. Eating a second prey type helps herbivores' populations stabilize. Alternating between two or more plant types provides population stability for the herbivore, while the populations of the plants oscillate. This plays an important role for generalist herbivores that eat a variety of plants. Keystone herbivores keep vegetation populations in check and allow for a greater diversity of both herbivores and plants. When an invasive herbivore or plant enters
3233-556: The size of herbivores having an effect on the amount of energy intake that is needed, larger herbivores need to forage on higher quality or more plants to gain the optimal amount of nutrients and energy compared to smaller herbivores. Environmental degradation from white-tailed deer ( Odocoileus virginianus ) in the US alone has the potential to both change vegetative communities through over-browsing and cost forest restoration projects upwards of $ 750 million annually. Another example of
3294-432: The subcostal vein curving forward at a right angle. The head is hemispherical and usually short. The face is vertical or retreating and the frons is broad. Ocelli and cellar bristles are present. The postvertical bristles are parallel to divergent. Two to eight pairs of frontal bristles are seen (at least one but usually several lower pairs curving inwards and at least one of the upper pairs curving backwards). In some species,
3355-453: The system, the balance is thrown off and the diversity can collapse to a monotaxon system. The back and forth relationship of plant defense and herbivore offense drives coevolution between plants and herbivores, resulting in a "coevolutionary arms race". The escape and radiation mechanisms for coevolution, presents the idea that adaptations in herbivores and their host plants, has been the driving force behind speciation . While much of
3416-485: The theme. The understanding of herbivory in geological time comes from three sources: fossilized plants, which may preserve evidence of defence (such as spines), or herbivory-related damage; the observation of plant debris in fossilised animal faeces ; and the construction of herbivore mouthparts. Although herbivory was long thought to be a Mesozoic phenomenon, fossils have shown that plants were being consumed by arthropods within less than 20 million years after
3477-421: The theory of predator –prey interactions, the relationship between herbivores and plants is cyclic. When prey (plants) are numerous their predators (herbivores) increase in numbers, reducing the prey population, which in turn causes predator number to decline. The prey population eventually recovers, starting a new cycle. This suggests that the population of the herbivore fluctuates around the carrying capacity of
3538-420: The use of cover sprays with conventional pesticides , however, due to deleterious impact of these pesticides, new, less impactful and more targeted pest control techniques have been used, such as toxic food baits , male annihilation technique using specific male attractant parapheromones in toxic baits or mass trapping , or even sterile insect technique as part of integrated pest management . Tephritidae
3599-504: The wild or commercially cultivated olive , Olea europaea . It has the capacity to ruin 100% of an olive crop by damaging the fruit. Bactrocera dorsalis is another highly invasive pest species that damages tropical fruit, vegetable, and nut crops. Euleia heraclei is a pest of celery and parsnips. The genus Anastrepha includes several important pests, notably A. grandis , A. ludens (Mexican fruit fly), A. obliqua , and A. suspensa . Other pests are Strauzia longipennis ,
3660-429: Was a gap of 50 to 100 million years between the time each organ evolved and the time organisms evolved to feed upon them; this may be due to the low levels of oxygen during this period, which may have suppressed evolution. Further than their arthropod status, the identity of these early herbivores is uncertain. Hole feeding and skeletonization are recorded in the early Permian , with surface fluid feeding evolving by
3721-431: Was composed of herbivorous dinosaurs. Carnivory was a natural transition from insectivory for medium and large tetrapods, requiring minimal adaptation. In contrast, a complex set of adaptations was necessary for feeding on highly fibrous plant materials. Arthropods evolved herbivory in four phases, changing their approach to it in response to changing plant communities. Tetrapod herbivores made their first appearance in
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