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Aphid Vectors
Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A typical life cycle involves flightless females giving live birth to female nymphs—who may also be already pregnant, an adaptation scientists call telescoping generations—without the involvement of males. Maturing rapidly, females breed profusely so that the number of these insects multiplies quickly. Winged females may develop later in the season, allowing the insects to colonize new plants. In temperate regions, a phase of sexual reproduction occurs in the autumn, with the insects often overwintering as eggs. The life cycle of some species involves an alternation between two species of host plants, for example between an annual crop and a woody plant. Some species feed on only one type of plant, while others are generalists, coloni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Étienne Louis Geoffroy
Étienne Louis Geoffroy (October 12, 1725 – August 12, 1810) was a French entomologist and pharmacist. He was born in Paris and died in Soissons. He followed the binomial nomenclature of Carl Linnaeus, Carl von Linné and devoted himself mainly to beetles. Geoffroy was the author of ''Histoire abrégée des Insectes qui se trouvent aux environs de Paris''. Paris : Durand Vol. 1 8 + 523 pp. 10 pls (1762) and co-author with Antoine François, comte de Fourcroy, Antoine François of ''Entomologia Parisiensis, sive, Catalogus insectorum quae in agro Parisiensi reperiuntur ...'' (1785). References * Jean Gouillard (2004). ''Histoire des entomologistes français, 1750-1950. Édition entièrement revue et augmentée.'' Boubée (Paris): p. 287 * Jean Lhoste (1987). ''Les Entomologistes français. 1750-1950. INRA Éditions: p. 351 {{DEFAULTSORT:Geoffroy, Etienne Louis French entomologists 1725 births 1810 deaths ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pregnancy
Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins. Pregnancy usually occurs by sexual intercourse, but can also occur through assisted reproductive technology procedures. A pregnancy may end in a live birth, a miscarriage, an induced abortion, or a stillbirth. Childbirth typically occurs around 40 weeks from the start of the last menstrual period (LMP), a span known as the gestational age. This is just over nine months. Counting by fertilization age, the length is about 38 weeks. Pregnancy is "the presence of an implanted human embryo or fetus in the uterus"; implantation occurs on average 8–9 days after fertilization. An '' embryo'' is the term for the developing offspring during the first seven weeks following implantation (i.e. ten weeks' gestational age), after which the term ''fetus'' is used until birth. Signs an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Honeydew (secretion)
Honeydew is a sugar-rich sticky liquid, secreted by aphids and some scale insects as they feed on plant sap. When their mouthpart penetrates the phloem, the sugary, high-pressure liquid is forced out of the anus of the aphid. Honeydew is particularly common as a secretion in hemipteran insects and is often the basis for trophobiosis. Some caterpillars of Lycaenidae butterflies and some moths also produce honeydew. Honeydew producing insects, like cicadas, pierce phloem ducts to access the sugar rich sap. The sap continues to bleed after the insects have moved on, leaving a white sugar crust called manna. Ants may collect, or "milk", honeydew directly from aphids and other honeydew producers, which benefit from their presence due to their driving away predators such as lady beetles or parasitic wasps—see ''Crematogaster peringueyi''. Animals and plants in a mutually symbiotic arrangement with ants are called Myrmecophiles. In Madagascar, some gecko species in the genera ''Ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mutualism (biology)
Mutualism describes the ecological interaction between two or more species where each species has a net benefit. Mutualism is a common type of ecological interaction. Prominent examples include most vascular plants engaged in mutualistic interactions with mycorrhizae, flowering plants being pollinated by animals, vascular plants being dispersed by animals, and corals with zooxanthellae, among many others. Mutualism can be contrasted with interspecific competition, in which each species experiences ''reduced'' fitness, and exploitation, or parasitism, in which one species benefits at the expense of the other. The term ''mutualism'' was introduced by Pierre-Joseph van Beneden in his 1876 book ''Animal Parasites and Messmates'' to mean "mutual aid among species". Mutualism is often conflated with two other types of ecological phenomena: cooperation and symbiosis. Cooperation most commonly refers to increases in fitness through within-species (intraspecific) interactions, althoug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gardener
A gardener is someone who practices gardening, either professionally or as a hobby. Description A gardener is any person involved in gardening, arguably the oldest occupation, from the hobbyist in a residential garden, the home-owner supplementing the family food with a small vegetable garden or orchard, to an employee in a plant nursery or the head gardener in a large estate. Garden design and maintenance The garden designer is someone who will design the garden, and the gardener is the person who will undertake the work to produce the desired outcome. Design The term gardener is also used to describe garden designers and landscape architects, who are involved chiefly in the design of gardens, rather than the practical aspects of horticulture. Garden design is considered to be an art in most cultures, distinguished from gardening, which generally means ''garden maintenance''. Vita Sackville-West, Gertrude Jekyll and William Robinson were garden designers as well as garden ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forestry
Forestry is the science and craft of creating, managing, planting, using, conserving and repairing forests, woodlands, and associated resources for human and environmental benefits. Forestry is practiced in plantations and natural stands. The science of forestry has elements that belong to the biological, physical, social, political and managerial sciences. Forest management play essential role of creation and modification of habitats and affect ecosystem services provisioning. Modern forestry generally embraces a broad range of concerns, in what is known as multiple-use management, including: the provision of timber, fuel wood, wildlife habitat, natural water quality management, recreation, landscape and community protection, employment, aesthetically appealing landscapes, biodiversity management, watershed management, erosion control, and preserving forests as " sinks" for atmospheric carbon dioxide. Forest ecosystems have come to be seen as the most important componen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agriculture
Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to live in cities. The history of agriculture began thousands of years ago. After gathering wild grains beginning at least 105,000 years ago, nascent farmers began to plant them around 11,500 years ago. Sheep, goats, pigs and cattle were domesticated over 10,000 years ago. Plants were independently cultivated in at least 11 regions of the world. Industrial agriculture based on large-scale monoculture in the twentieth century came to dominate agricultural output, though about 2 billion people still depended on subsistence agriculture. The major agricultural products can be broadly grouped into foods, fibers, fuels, and raw materials (such as rubber). Food classes include cereals (grains), vegetables, fruits, cooking oils, meat, milk, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fiber Crop
Fiber crops are field crops grown for their fibers, which are traditionally used to make paper, cloth, or rope. Fiber crops are characterized by having a large concentration of cellulose, which is what gives them their strength. The fibers may be chemically modified, like in viscose (used to make rayon and cellophane). In recent years, materials scientists have begun exploring further use of these fibers in composite materials. Due to cellulose being the main factor of a plant fiber's strength, this is what scientists are looking to manipulate to create different types of fibers. Fiber crops are generally harvestable after a single growing season, as distinct from trees, which are typically grown for many years before being harvested for such materials as wood pulp fiber or lacebark. In specific circumstances, fiber crops can be superior to wood pulp fiber in terms of technical performance, environmental impact or cost. There are a number of issues regarding the use of fiber c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crop
A crop is a plant that can be grown and harvested extensively for profit or subsistence. When the plants of the same kind are cultivated at one place on a large scale, it is called a crop. Most crops are cultivated in agriculture or hydroponics. Crops may include macroscopic fungus (e.g. mushrooms) and marine macroalga (e.g. seaweed), some of which are grown in aquaculture. Most crops are harvested as food for humans or fodder for livestock. Some crops are gathered from the wild often in a form of intensive gathering (e.g. ginseng, yohimbe, and eucommia). Important non-food crops include horticulture, floriculture and industrial crops. Horticulture crops include plants used for other crops (e.g. fruit trees). Floriculture crops include bedding plants, houseplants, flowering garden and pot plants, cut cultivated greens, and cut flowers. Industrial crops are produced for clothing ( fiber crops e.g. cotton), biofuel ( energy crops, algae fuel), or medicine ( medicinal plants). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Woody Plant
A woody plant is a plant that produces wood as its structural tissue and thus has a hard stem. In cold climates, woody plants further survive winter or dry season above ground, as opposite to herbaceous plants that die back to the ground until spring. Characteristics Woody plants are usually either trees, shrubs, or lianas. These are usually perennial plants whose stems and larger roots are reinforced with wood produced from secondary xylem. The main stem, larger branches, and roots of these plants are usually covered by a layer of bark. Wood is a structural tissue that allows woody plants to grow from above ground stems year after year, thus making some woody plants the largest and tallest terrestrial plants. Woody plants, like herbaceous perennials, typically have a dormant period of the year when growth does not take place, in colder climates due to freezing temperatures and lack of daylight during the winter months, in subtropical and tropical climates due to the dry sea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autumn
Autumn, also known as fall in American English and Canadian English, is one of the four temperate seasons on Earth. Outside the tropics, autumn marks the transition from summer to winter, in September ( Northern Hemisphere) or March ( Southern Hemisphere). Autumn is the season when the duration of daylight becomes noticeably shorter and the temperature cools considerably. Day length decreases and night length increases as the season progresses until the Winter Solstice in December (Northern Hemisphere) and June (Southern Hemisphere). One of its main features in temperate climates is the striking change in colour for the leaves of deciduous trees as they prepare to shed. Date definitions Some cultures regard the autumnal equinox as "mid-autumn", while others with a longer temperature lag treat the equinox as the start of autumn. In the English-speaking world of high latitude countries, autumn traditionally began with Lammas Day and ended around Hallowe'en, the approxima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Reproduction
Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete ( haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote that develops into an organism composed of cells with two sets of chromosomes ( diploid). This is typical in animals, though the number of chromosome sets and how that number changes in sexual reproduction varies, especially among plants, fungi, and other eukaryotes. Sexual reproduction is the most common life cycle in multicellular eukaryotes, such as animals, fungi and plants. Sexual reproduction also occurs in some unicellular eukaryotes. Sexual reproduction does not occur in prokaryotes, unicellular organisms without cell nuclei, such bacteria and archaea. However, some process in bacteria may be considered analogous to sexual reproduction in that they incorporate new genetic information, including bacterial conjugation, transformatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
