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Cornicle
The cornicle (or siphuncule) is one of a pair of small upright backward-pointing tubes found on the dorsal side of the 5th or 6th abdominal segments of aphids. They are sometimes mistaken for cerci. They are no more than pores in some species. These abdominal tubes exude droplets of a quick-hardening defensive fluid''Aphid'', Henry G. Stroyan, McGraw-Hill Encyclopedia of Science and Technology, 8th Edition, 1997, containing triacylglycerols called ''cornicle wax''. There is some confusion in the literature about the function of the cornicle wax secretions. It was common at one time to suggest that the cornicles were the source of the honeydew, and this was even included in the ''Shorter Oxford English Dictionary'' and the 2008 edition of the World Book Encyclopedia The ''World Book Encyclopedia'' is an American encyclopedia. The encyclopedia is designed to cover major areas of knowledge uniformly, but it shows particular strength in scientific, technical, historical and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cornicle
The cornicle (or siphuncule) is one of a pair of small upright backward-pointing tubes found on the dorsal side of the 5th or 6th abdominal segments of aphids. They are sometimes mistaken for cerci. They are no more than pores in some species. These abdominal tubes exude droplets of a quick-hardening defensive fluid''Aphid'', Henry G. Stroyan, McGraw-Hill Encyclopedia of Science and Technology, 8th Edition, 1997, containing triacylglycerols called ''cornicle wax''. There is some confusion in the literature about the function of the cornicle wax secretions. It was common at one time to suggest that the cornicles were the source of the honeydew, and this was even included in the ''Shorter Oxford English Dictionary'' and the 2008 edition of the World Book Encyclopedia The ''World Book Encyclopedia'' is an American encyclopedia. The encyclopedia is designed to cover major areas of knowledge uniformly, but it shows particular strength in scientific, technical, historical and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aphids
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] |
Cercus
Cerci (singular cercus) are paired appendages on the rear-most segments of many arthropods, including insects and symphylans. Many forms of cerci serve as sensory organs, but some serve as pinching weapons or as organs of copulation. In many insects, they simply may be functionless vestigial structures. In basal arthropods, such as silverfish, the cerci originate from the eleventh abdominal segment. As segment eleven is reduced or absent in the majority of arthropods, in such cases, the cerci emerge from the tenth abdominal segment. It is not clear that other structures so named are homologous. In the Symphyla they are associated with spinnerets. Morphology and functions Most cerci are segmented and jointed, or filiform (threadlike), but some take very different forms. Some Diplura, in particular ''Japyx'' species, have large, stout forcipate (pincer-like) cerci that they use in capturing their prey. The Dermaptera, or earwigs, are well known for the forcipate cerci that m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
McGraw-Hill Encyclopedia Of Science And Technology
McGraw Hill is an American educational publishing company and one of the "big three" educational publishers that publishes educational content, software, and services for pre-K through postgraduate education. The company also publishes reference and trade publications for the medical, business, and engineering professions. McGraw Hill operates in 28 countries, has about 4,000 employees globally, and offers products and services to about 140 countries in about 60 languages. Formerly a division of The McGraw Hill Companies (later renamed McGraw Hill Financial, now S&P Global), McGraw Hill Education was divested and acquired by Apollo Global Management in March 2013 for $2.4 billion in cash. McGraw Hill was sold in 2021 to Platinum Equity for $4.5 billion. Corporate History McGraw Hill was founded in 1888 when James H. McGraw, co-founder of the company, purchased the ''American Journal of Railway Appliances''. He continued to add further publications, eventually establishing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triacylglycerol
A triglyceride (TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids (from ''tri-'' and ''glyceride''). Triglycerides are the main constituents of body fat in humans and other vertebrates, as well as vegetable fat. They are also present in the blood to enable the bidirectional transference of adipose fat and blood glucose from the liver, and are a major component of human skin oils. Many types of triglycerides exist. One specific classification focuses on saturated and unsaturated types. Saturated fats have ''no'' C=C groups; unsaturated fats feature one or more C=C groups. Unsaturated fats tend to have a lower melting point than saturated analogues; as a result, they are often liquid at room temperature. Chemical structure Triglycerides are tri-esters consisting of a glycerol bound to three fatty acid molecules. Alcohols have a hydroxyl (HO–) group. Organic acids have a carboxyl (–COOH) group. Alcohols and organ ... [...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 '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shorter Oxford English Dictionary
The ''Shorter Oxford English Dictionary'' (''SOED'') is an English language dictionary published by the Oxford University Press. The SOED is a two-volume abridgement of the twenty-volume ''Oxford English Dictionary'' (''OED''). Print editions Prequel The first editor, William Little, worked on the book from 1902 until his death in 1922. The dictionary was completed by H. W. Fowler, Jessie Coulson, and C. T. Onions. An abridgement of the complete work was contemplated from 1879, when the Oxford University Press took over from the Philological Society on what was then known as ''A New English Dictionary on Historical Principles''. However, no action was taken until 1902, when the work was begun by William Little, a fellow of Corpus Christi College, Oxford. He laboured until his death in 1922, at which point he had completed "A" to "T", and "V". The remaining letters were completed by H. W. Fowler ("U", "X", "Y", and "Z") and Mrs. E. A. Coulson (Jessie Coulson) ("W") under the d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World Book Encyclopedia
The ''World Book Encyclopedia'' is an American encyclopedia. The encyclopedia is designed to cover major areas of knowledge uniformly, but it shows particular strength in scientific, technical, historical and medical subjects. ''World Book'' was first published in 1917. Since 1925, a new edition of the encyclopedia has been published annually. World Book, Inc. is based in Chicago, Illinois. According to the company, the latest edition, ''World Book Encyclopedia 2022'', contains more than 14,000 pages distributed along 22 volumes and also contains over 25,000 photographs. World Book also publishes children's non-fiction and picture books under the Bright Connections Media imprint, and educational development and supplemental instructional resources through Incentive Publications by ''World Book''. History World Book was founded in Chicago by publishers J. H. Hansen and John Bellow, who realized that existing encyclopedias were off-putting to readers. In 1915, they enlisted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aphids
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] |
