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Hormaphis Hamamelidis
The witch-hazel cone gall aphid (''Hormaphis hamamelidis'') is a minuscule insect, a member of the Aphid, aphid superfamily, whose presence on a witch-hazel (''Hamamelis virginiana'') plant is easily recognizable by a conical gall structure. The gall is green at first, then turns bright red. This gall, rich in nutrients, provides both food and shelter for the female aphid. ''H. hamamelidis'' have three generations per year, each with a different part in the life cycle. At the start of spring, females or ''stem mothers'' crawl to witch-hazel leaf buds. As the leaf grows, the aphid injects it with a substance, possibly an enzyme or hormone, that causes that the galls to form around her. Once inside her gall, the stem mother reproduces Parthenogenesis, parthenogenically and fills the gall with 50–70 female offspring. The second generation develops wings and disperses, repeating the process. The third generation includes both males and females. Towards the end of summer, the thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asa Fitch
Asa Fitch (February 24, 1809 – April 8, 1879) was a natural historian and entomologist from Salem, New York. His early studies were of both natural history and medicine, which he studied at the newly formed Rensselaer Polytechnic Institute, graduating in 1827. However, in 1838 he decided to start studying agriculture and entomology. In 1838 he began to collect and study insects for New York state. In 1854 he became the first professional entomologist of New York State Agricultural Society (commissioned by the State of New York). This made him the first occupational entomologist in the United States. His vast studies of many insects helped scientists to solve some of the problems of crop damage caused by insects. Many of his notebooks are now the property of the Smithsonian Institution. Fitch also discovered the rodent botfly '' Cuterebra emasculator'' in 1856. He died April 8, 1879, in Salem, New York. The Martin–Fitch House and Asa Fitch Jr. Laboratory was added to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aphid
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, c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Witch-hazel
Witch-hazels or witch hazels (''Hamamelis'') are a genus of flowering plants in the family Hamamelidaceae, with three species in North America ('' H. ovalis'', '' H. virginiana'', and '' H. vernalis''), and one each in Japan ('' H. japonica'') and China ('' H. mollis''). The North American species are occasionally called winterbloom. Growth The witch-hazels are deciduous shrubs or (rarely) small trees growing to 3 to 7.5 m tall, even more rarely to 12 m tall. The leaves are alternately arranged, oval, 5 to 15 cm long, and 2.5 to 10 cm wide, with a smooth or wavy margin. The genus name, ''Hamamelis'', means "together with fruit", referring to the simultaneous occurrence of flowers with the maturing fruit from the previous year. ''H. virginiana'' blooms in September–November while the other species bloom from January–March. Each flower has four slender strap-shaped petals 1 to 2 cm long, pale to dark yellow, orange, or red. The fruit is a two-part capsu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gall
Galls (from the Latin , 'oak-apple') or ''cecidia'' (from the Greek , anything gushing out) are a kind of swelling growth on the external Tissue (biology), tissues of plants, fungi, or animals. Plant galls are abnormal outgrowths of plant tissues, similar to benign tumors or warts in animals. They can be caused by various parasites, from viruses, fungi and bacteria, to other plants, insects and mites. Plant galls are often highly organized structures so that the cause of the gall can often be determined without the actual agent being identified. This applies particularly to some insect and mite plant galls. The study of plant galls is known as cecidology. In human pathology, a gall is a raised sore on the skin, usually caused by chafing or rubbing. Causes of plant galls Insects and mites Insect galls are the highly distinctive plant structures formed by some Herbivore, herbivorous insects as their own microhabitats. They are plant tissue which is controlled by the insect. Gal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hormaphis Hamamelidis Gall
''Hormaphis'' is a genus of witch hazel and palm aphids in the family Aphididae. There are at least three described species in ''Hormaphis'', found mainly in eastern North America. Species These three species belong to the genus ''Hormaphis'': * ''Hormaphis betulae'' (Mordvilko, 1901) * ''Hormaphis cornu'' (Shimer, 1867) * ''Hormaphis hamamelidis The witch-hazel cone gall aphid (''Hormaphis hamamelidis'') is a minuscule insect, a member of the Aphid, aphid superfamily, whose presence on a witch-hazel (''Hamamelis virginiana'') plant is easily recognizable by a conical gall structure. The ...'' (Fitch, 1851) (witch hazel cone gall aphid) References Further reading * * Aphids Taxa named by Carl Robert Osten-Sacken {{sternorrhyncha-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aphid Galls
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] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecules known as product (chemistry), products. Almost all metabolism, metabolic processes in the cell (biology), cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme, pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are Ribozyme, catalytic RNA molecules, called ribozymes. Enzymes' Chemical specificity, specific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hormone
A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are required for the correct development of animals, plants and fungi. Due to the broad definition of a hormone (as a signaling molecule that exerts its effects far from its site of production), numerous kinds of molecules can be classified as hormones. Among the substances that can be considered hormones, are eicosanoids (e.g. prostaglandins and thromboxanes), steroids (e.g. oestrogen and brassinosteroid), amino acid derivatives (e.g. epinephrine and auxin), protein or peptides (e.g. insulin and CLE peptides), and gases (e.g. ethylene and nitric oxide). Hormones are used to communicate between organs and tissues. In vertebrates, hormones are responsible for regulating a variety of physiological processes and behavioral activities such as diges ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parthenogenesis
Parthenogenesis (; from the Greek grc, παρθένος, translit=parthénos, lit=virgin, label=none + grc, γένεσις, translit=génesis, lit=creation, label=none) is a natural form of asexual reproduction in which growth and development of embryos occur in a gamete (egg or sperm) without combining with another gamete (e.g., egg and sperm fusing). In animals, parthenogenesis means development of an embryo from an unfertilized egg cell. In plants, parthenogenesis is a component process of apomixis. In algae, parthenogenesis can mean the development of an embryo from either an individual sperm or an individual egg. Parthenogenesis occurs naturally in some plants, algae, invertebrate animal species (including nematodes, some tardigrades, water fleas, some scorpions, aphids, some mites, some bees, some Phasmatodea and parasitic wasps) and a few vertebrates (such as some fish, amphibians, reptiles and birds). This type of reproduction has been induced artificiall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hormaphis Cornu
''Hormaphis'' is a genus of witch hazel and palm aphids in the family Aphididae. There are at least three described species in ''Hormaphis'', found mainly in eastern North America. Species These three species belong to the genus ''Hormaphis'': * '' Hormaphis betulae'' (Mordvilko, 1901) * '' Hormaphis cornu'' (Shimer, 1867) * ''Hormaphis hamamelidis The witch-hazel cone gall aphid (''Hormaphis hamamelidis'') is a minuscule insect, a member of the Aphid, aphid superfamily, whose presence on a witch-hazel (''Hamamelis virginiana'') plant is easily recognizable by a conical gall structure. The ...'' (Fitch, 1851) (witch hazel cone gall aphid) References Further reading * * Aphids Taxa named by Carl Robert Osten-Sacken {{sternorrhyncha-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autoecious
A heteroecious parasite is one that requires at least two hosts. The ''primary host'' is the host in which the parasite spends its adult life; the other is the ''secondary host''. Both hosts are required for the parasite to complete its life cycle. This can be contrasted with an autoecious parasite which can complete its life cycle on a single host species. Many rust fungi have heteroecious life cycles: In parasitology, heteroxeny, or heteroxenous development, is a synonymous term that characterizes a parasite whose development involves several hosts. Fungal examples * ''Gymnosporangium'' (Cedar-apple rust): the juniper is the primary (telial) host and the apple, pear or hawthorn is the secondary (aecial) host. * '' Cronartium ribicola'' (White pine blister rust): the primary host are white pines, and currants the secondary. * ''Hemileia vastatrix ''Hemileia vastatrix'' is a multicellular basidiomycete fungus of the order Pucciniales (previously also known as Ured ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hybrid Inviability
Hybrid inviability is a post-zygotic barrier, which reduces a hybrid's capacity to mature into a healthy, fit adult. The relatively low health of these hybrids relative to pure-breed individuals prevents gene flow between species. Thus, hybrid inviability acts as an isolating mechanism, limiting hybridization and allowing for the differentiation of species. The barrier of hybrid inviability occurs after mating species overcome pre-zygotic barriers (behavioral, mechanical, etc.) to produce a zygote. The barrier emerges from the cumulative effect of parental genes; these conflicting genes interfere with the embryo's development and prevents its maturation. Most often, the hybrid embryo dies before birth. However, sometimes, the offspring develops fully with mixed traits, forming a frail, often infertile adult. This hybrid displays reduced fitness, marked by decreased rates of survival and reproduction relative to the parent species. The offspring fails to compete with purebr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
