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Phymata Americana
''Phymata americana'' is a Phymatinae, or ambush bug in the family Reduviidae. It can be found on the flowers of various plants in Central America and North America, where it waits to prey on other insects. Subspecies These four subspecies belong to the species ''Phymata americana'': * ''Phymata americana americana'' Melin, 1930 * ''Phymata americana coloradensis'' Melin, 1930 * ''Phymata americana metcalfi'' Evans, 1931 * ''Phymata americana obscura'' Kormilev, 1957 Data sources: i = ITIS, c = Catalogue of Life, g = GBIF, b = Bugguide.net Habitat ''Phymata americana'' are found in open fields of flowering plants near rural forest edges, farms, and urban areas. Camouflage and color polymorphism Although ''P. americana'' can be found on many species of flowering plants, they tend to prefer either yellow or blue flowers over red or white flowers. Variation in flower color choice may reflect individual variation in ''P. americana'' color pattern, where individuals prefer flower ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Douglas Melin
Douglas Edvard Melin (4 October 1895 – 29 March 1946) was a Swedish zoologist and athlete. He was the nephew of Olof Melin. Athletic career He competed in the men's standing long jump at the 1912 Summer Olympics. He was also an avid boxer. Scientific career Melin was an all-sided zoologist who got his education at the Uppsala University Uppsala University ( sv, Uppsala universitet) is a public research university in Uppsala, Sweden. Founded in 1477, it is the oldest university in Sweden and the Nordic countries still in operation. The university rose to significance during ... and spent his career there. In 1923–26 he led an expedition to Brazil and Peru, which resulted in a large number of zoological specimens as well as ethnographic and cartographic observations. Melin was skeptical about Darwin's theories, which led to his isolation as a scientist. References External links * {{DEFAULTSORT:Melin, Douglas 1895 births 1946 deaths Swedish zoologists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Dimorphism
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most animals and some plants. Differences may include secondary sex characteristics, size, weight, colour, markings, or behavioural or cognitive traits. These differences may be subtle or exaggerated and may be subjected to sexual selection and natural selection. The opposite of dimorphism is ''monomorphism'', which is when both biological sexes are phenotypically indistinguishable from each other. Overview Ornamentation and coloration Common and easily identified types of dimorphism consist of ornamentation and coloration, though not always apparent. A difference in coloration of sexes within a given species is called sexual dichromatism, which is commonly seen in many species of birds and reptiles. Sexual selection leads to the exaggerated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemiptera Of North America
Hemiptera (; ) is an order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, assassin bugs, bed bugs, and shield bugs. They range in size from to around , and share a common arrangement of piercing-sucking mouthparts. The name "true bugs" is often limited to the suborder Heteroptera. Entomologists reserve the term ''bug'' for Hemiptera or Heteroptera,Gilbert Waldbauer. ''The Handy Bug Answer Book.'' Visible Ink, 1998p. 1. which does not include other arthropods or insects of other orders such as ants, bees, beetles, or butterflies. In some variations of English, all terrestrial arthropods (including non-insect arachnids, and myriapods) also fall under the colloquial understanding of ''bug''. Many insects with "bug" in their common name, especially in American English, belong to other orders; for example, the lovebug is a fly and the Maybug and ladybug are beetles. The term is also occas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sex Ratio
The sex ratio (or gender ratio) is usually defined as the ratio of males to females in a population. As explained by Fisher's principle, for evolutionary reasons this is typically about 1:1 in species which reproduce sexually. Many species deviate from an even sex ratio, either periodically or permanently. Examples include parthenogenic species, periodically mating organisms such as aphids, some eusocial wasps, bees, ants, and termites. The human sex ratio is of particular interest to anthropologists and demographers. In human societies, sex ratios at birth may be considerably skewed by factors such as the age of mother at birth and by sex-selective abortion and infanticide. Exposure to pesticides and other environmental contaminants may be a significant contributing factor as well. As of 2014, the global sex ratio at birth is estimated at 107 boys to 100 girls (1,000 boys per 934 girls).. Types In most species, the sex ratio varies according to the age profile of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demography
Demography () is the statistical study of populations, especially human beings. Demographic analysis examines and measures the dimensions and dynamics of populations; it can cover whole societies or groups defined by criteria such as education, nationality, religion, and ethnicity. Educational institutions usually treat demography as a field of sociology, though there are a number of independent demography departments. These methods have primarily been developed to study human populations, but are extended to a variety of areas where researchers want to know how populations of social actors can change across time through processes of birth, death, and migration. In the context of human biological populations, demographic analysis uses administrative records to develop an independent estimate of the population. Demographic analysis estimates are often considered a reliable standard for judging the accuracy of the census information gathered at any time. In the lab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Selection
Sexual selection is a mode of natural selection in which members of one biological sex choose mates of the other sex to mate with (intersexual selection), and compete with members of the same sex for access to members of the opposite sex (intrasexual selection). These two forms of selection mean that some individuals have greater reproductive success than others within a population, for example because they are more attractive or prefer more attractive partners to produce offspring. Successful males benefit from frequent mating and monopolizing access to one or more fertile females. Females can maximise the return on the energy they invest in reproduction by selecting and mating with the best males. The concept was first articulated by Charles Darwin who wrote of a "second agency" other than natural selection, in which competition between mate candidates could lead to speciation. The theory was given a mathematical basis by Ronald Fisher in the early 20th century. Sex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Courtship Display
A courtship display is a set of display behaviors in which an animal, usually a male, attempts to attract a mate; the mate exercises choice, so sexual selection acts on the display. These behaviors often include ritualized movement ("dances"), vocalizations, mechanical sound production, or displays of beauty, strength, or agonistic ability. Male display In some species, males will perform ritualized movements to attract females. The male six-plumed bird-of-paradise ( ''Parotia lawesii'') exemplifies male courtship display with its ritualized "ballerina dance" and unique occipital and breast feathers that serve to stimulate the female visual system. In ''Drosophila subobscura,'' male courtship display is seen through the male's intricate wing scissoring patterns and rapid sidestepping. These stimulations, along with many other factors, result in subsequent copulation or rejection. In other species, males may exhibit courtship displays that serve as both visual and auditory st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condition-dependant Signaling
Condition-dependent signaling is a component of sexual selection. Its exact definition remains elusive due to the vagueness of the terms “condition” and “signaling”. It examines which conditions favor the extravagant displays and ornaments, or signals, some organisms poses, despite their lack of evolutionary value in terms of fitness. Condition-dependent signaling can affect individual mating tactics and depend on an individual's size, age, or other physical factors, such as a more fit individual being able to produce a stronger call than its less fit cohort. It can also impact the signaling choices of organisms based on the environment around them, like vocalizations that are more favorable in lower density environments. Background It is energetically expensive to produce a sexual signal. In some organisms the sexual signal may also have costs in terms of predation. For example, the ornate tail of a peacock makes it more difficult to hide and it also impedes flight. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mate Choice
Mate choice is one of the primary mechanisms under which evolution can occur. It is characterized by a "selective response by animals to particular stimuli" which can be observed as behavior.Bateson, Paul Patrick Gordon. "Mate Choice." Mate Choice, Cambridge University Press, 1985 In other words, before an animal engages with a potential mate, they first evaluate various aspects of that mate which are indicative of quality—such as the resources or phenotypes they have—and evaluate whether or not those particular trait(s) are somehow beneficial to them. The evaluation will then incur a response of some sort. These mechanisms are a part of evolutionary change because they operate in a way that causes the qualities that are desired in a mate to be more frequently passed on to each generation over time. For example, if female peacocks desire mates who have a colourful plumage, then this trait will increase in frequency over time as male peacocks with a colourful plumage will hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phymatinae
Insects in the subfamily Phymatinae are commonly called ambush bugs after their habit of lying in wait for prey, relying on their superb camouflage. Armed with raptorial forelegs, ambush bugs routinely capture prey ten or more times their own size. They form a subgroup within the assassin bugs. Description Phymatinae are long. The most distinguishable trait of this group is the presence of pronounced raptorial forelegs. In ''Phymata'', the scutellum is triangular and shorter than the pronotum. In ''Macrocephalus'', the scutellum is narrow and rounded, extending to the tip of the abdomen. Phymatinae normally have a large fore femur and clubbed antennae. The forewing membranes sometimes lack distinct cells. The antennae have four segments. There are two ocelli. The beak has three segments. The tarsi also have three segments. The rear half of the abdomen expands beyond the edges of the wings. Compared to classic assassin bugs, ambush bugs are shorter, stouter, more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stridulation
Stridulation is the act of producing sound by rubbing together certain body parts. This behavior is mostly associated with insects, but other animals are known to do this as well, such as a number of species of fish, snakes and spiders. The mechanism is typically that of one structure with a well-defined lip, ridge, or nodules (the "scraper" or ''plectrum'') being moved across a finely-ridged surface (the "file" or ''stridulitrum''—sometimes called the ''pars stridens'') or vice versa, and vibrating as it does so, like the dragging of a phonograph needle across a vinyl record. Sometimes it is the structure bearing the file which resonates to produce the sound, but in other cases it is the structure bearing the scraper, with both variants possible in related groups. Common onomatopoeic words for the sounds produced by stridulation include ''chirp'' and ''chirrup''. Arthropod stridulation Insects and other arthropods stridulate by rubbing together two parts of the body. These ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Dimorphism
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most animals and some plants. Differences may include secondary sex characteristics, size, weight, colour, markings, or behavioural or cognitive traits. These differences may be subtle or exaggerated and may be subjected to sexual selection and natural selection. The opposite of dimorphism is ''monomorphism'', which is when both biological sexes are phenotypically indistinguishable from each other. Overview Ornamentation and coloration Common and easily identified types of dimorphism consist of ornamentation and coloration, though not always apparent. A difference in coloration of sexes within a given species is called sexual dichromatism, which is commonly seen in many species of birds and reptiles. Sexual selection leads to the exaggerated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
