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Aphidius Nigripes
''Aphidius nigripes'' is a species of parasitoid wasp in the subfamily Aphidiinae of the family Braconidae. It is the most common parasitoid of the potato aphid '' Macrosiphum euphorbiae'' in eastern North America. Many other species of aphids may also serve as hosts. Ecology Adult ''A. nigripes'' emerge in the spring and find ''M. euphorbiae'' hosts before the aphid moves from its winter food plant, or primary host plant. Around June, the aphid moves to its secondary host, the potato, and the wasp accompanies it. Female ''Aphidius nigripes'' emit pheromones soon after emerging from their pupa to attract winged males. The female mates only once, storing the sperm. She oviposits eggs into the immature stages of the potato aphid. Like other haplodiploid insects, she can control the sex of her offspring by laying a fertilized (female) egg or an unfertilized (male) egg. There is a trend for ''A. nigripes'' to preferentially allocate unfertilized male eggs to the earlier, smaller in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Harris Ashmead
William Harris Ashmead was an American entomologist born on 19 September 1855 at Philadelphia. He died 17 October 1908 at Washington D.C. After his studies in Philadelphia, Ashmead worked for the publisher J. B. Lippincott & Co. Later, he settled in Florida where he formed his own publishing house devoted to agriculture. He also launched the '' Florida Dispatch'', an agricultural weekly magazine which included a headed section devoted to injurious insects. In 1879, he began writing papers for scientific publications and, in 1887, he became a field entomologist working for the Ministry for the Agriculture of Florida. The following year, he became entomologist at the Agricultural Research station of Lake City. In 1889, he worked again for the Ministry for Agriculture. The following year, and for two years, he traveled, in particular to Germany, to perfect his entomological knowledge. In 1895, he obtained the post of conservation assistant in the Department of Entomology of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasitoid
In evolutionary ecology, a parasitoid is an organism that lives in close association with its host (biology), host at the host's expense, eventually resulting in the death of the host. Parasitoidism is one of six major evolutionarily stable strategy, evolutionary strategies within parasitism, distinguished by the fatal prognosis for the host, which makes the strategy close to predation. Among parasitoids, strategies range from living inside the host (''endoparasitism''), allowing it to continue growing before emerging as an adult, to Paralysis, paralysing the host and living outside it (''ectoparasitism''). Hosts can include other parasitoids, resulting in hyperparasitism; in the case of oak galls, up to five levels of parasitism are possible. Some parasitoids Behavior-altering parasite, influence their host's behaviour in ways that favour the propagation of the parasitoid. Parasitoids are found in a variety of Taxon, taxa across the insect superorder Endopterygota, whose compl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aphidiinae
The Aphidiinae are a subfamily of tiny parasitoid wasps that use aphids as their hosts. Several species have been used in biological control programs of various aphids. Biology and distribution Aphidiines are koinobiont endoparasitoids of adult and immature aphids. While the larva of the 2–3 mm long '' Praon'' leaves the hollowed shell of the aphid from below to pupate in a volcano-like cocoon, most other Aphidiinae pupate inside the dead aphid and break out afterwards. These wasps are found worldwide, but are primarily found in the northern hemisphere. Several species have been introduced to countries outside of their natural range, both accidentally and purposefully for biocontrol. Systematics Although they have often been treated as a separate family, the Aphidiidae, the Aphidiinae are a lineage within the Braconidae. It is not yet clear to which braconid subfamilies they are most closely related. The Aphidiinae are subdivided into several tribes, the Ephedrin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Braconidae
The Braconidae are a family of parasitoid wasps. After the closely related Ichneumonidae, braconids make up the second-largest family in the order Hymenoptera, with about 17,000 recognized species and many thousands more undescribed. One analysis estimated a total between 30,000 and 50,000, and another provided a narrower estimate between 42,000 and 43,000 species. Classification The Braconidae are currently divided into about 47 subfamilies and over 1000 genera, which include '' Aerophilus'', ''Aleiodes'', ''Apanteles'', '' Asobara'', '' Bracon'', '' Cenocoelius'', '' Chaenusa'', '' Chorebus'', ''Cotesia'', '' Dacnusa'', '' Diachasma'', ''Microgaster'', '' Opius'', '' Parapanteles'', '' Phaenocarpa'', ''Spathius'', and '' Syntretus.'' These fall into two major groups, informally called the cyclostomes and noncyclostomes. In cyclostome braconids, the labrum and the lower part of the clypeus are concave with respect to the upper clypeus and the dorsal margin of the mandibles. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrosiphum Euphorbiae
''Macrosiphum euphorbiae'', the potato aphid, is a sap-sucking pest insect in the family Aphididae. It infests potatoes and a number of other commercially important crops. Distribution ''Macrosiphum euphorbiae'' originated in North America but it has spread to the temperate parts of Europe and Asia and is found in all areas in which potatoes are grown. Description The wingless female potato aphid is green or occasionally pink, often with a darker dorsal stripe. It has a pear-shaped body reaching about four millimetres long. The antennae are dark at the joints between the segments and are longer than the body. They are set on outward facing tubercles. The legs are longer than in other aphids, pale green but darker at the apices. The siphunculi are pale coloured, cylindrical with dark tips and operculi, and are about one third the length of the body. The tail is sword-shaped and bears 6 to 12 hairs and is much shorter than the siphunculi. The winged female has a uniform darker ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pheromone
A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavior of the receiving individuals. There are ''alarm pheromones'', ''food trail pheromones'', ''sex pheromones'', and many others that affect behavior or physiology. Pheromones are used by many organisms, from basic unicellular prokaryotes to complex multicellular eukaryotes. Their use among insects has been particularly well documented. In addition, some vertebrates, plants and ciliates communicate by using pheromones. The ecological functions and evolution of pheromones are a major topic of research in the field of chemical ecology. Background The portmanteau word "pheromone" was coined by Peter Karlson and Martin Lüscher in 1959, based on the Greek φερω ''pheroo'' ('I carry') and ὁρμων ''hormon'' ('stimulating'). Pheromones ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ovipositor
The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typically its form is adapted to functions such as preparing a place for the egg, transmitting the egg, and then placing it properly. For most insects, the organ is used merely to attach the egg to some surface, but for many parasitic species (primarily in wasps and other Hymenoptera), it is a piercing organ as well. Some ovipositors only retract partly when not in use, and the basal part that sticks out is known as the scape, or more specifically oviscape, the word ''scape'' deriving from the Latin word '' scāpus'', meaning "stalk" or "shaft". In insects Grasshoppers use their ovipositors to force a burrow into the earth to receive the eggs. Cicadas pierce the wood of twigs with their ovipositors to insert the eggs. Sawflies slit the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplodiploidy
Haplodiploidy is a sex-determination system in which males develop from unfertilized eggs and are haploid, and females develop from fertilized eggs and are diploid. Haplodiploidy is sometimes called arrhenotoky. Haplodiploidy determines the sex in all members of the insect orders Hymenoptera (bees, ants, and wasps) and Thysanoptera ('thrips'). The system also occurs sporadically in some spider mites, Hemiptera, Coleoptera (bark beetles), and rotifers. In this system, sex is determined by the number of sets of chromosomes an individual receives. An offspring formed from the union of a sperm and an egg develops as a female, and an unfertilized egg develops as a male. This means that the males have half the number of chromosomes that a female has, and are haploid. The haplodiploid sex-determination system has a number of peculiarities. For example, a male has no father and cannot have sons, but he has a grandfather and can have grandsons. Additionally, if a eusocial-insect colo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instar
An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, changes in the number of body segments or head width. After shedding their exoskeleton (moulting), the juvenile arthropods continue in their life cycle until they either pupate or moult again. The instar period of growth is fixed; however, in some insects, like the salvinia stem-borer moth, the number of instars depends on early larval nutrition. Some arthropods can continue to moult after sexual maturity, but the stages between these subsequent moults are generally not called instars. For most insect species, an ''instar'' is the developmental stage of the larval forms of holometabolous (complete metamorphism) or nymphal fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Host (biology)
In biology and medicine, a host is a larger organism that harbours a smaller organism; whether a parasitic, a mutualistic, or a commensalist ''guest'' (symbiont). The guest is typically provided with nourishment and shelter. Examples include animals playing host to parasitic worms (e.g. nematodes), cells harbouring pathogenic (disease-causing) viruses, a bean plant hosting mutualistic (helpful) nitrogen-fixing bacteria. More specifically in botany, a host plant supplies food resources to micropredators, which have an evolutionarily stable relationship with their hosts similar to ectoparasitism. The host range is the collection of hosts that an organism can use as a partner. Symbiosis Symbiosis spans a wide variety of possible relationships between organisms, differing in their permanence and their effects on the two parties. If one of the partners in an association is much larger than the other, it is generally known as the host. In parasitism, the parasite benefits a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperparasite
A hyperparasite, also known as a metaparasite, is a parasite whose host, often an insect, is also a parasite, often specifically a parasitoid. Hyperparasites are found mainly among the wasp-waisted Apocrita within the Hymenoptera, and in two other insect orders, the Diptera (true flies) and Coleoptera (beetles). Seventeen families in Hymenoptera and a few species of Diptera and Coleoptera are hyperparasitic. Hyperparasitism developed from primary parasitism, which evolved in the Jurassic period in the Hymenoptera. Hyperparasitism intrigues entomologists because of its multidisciplinary relationship to evolution, ecology, behavior, biological control, taxonomy, and mathematical models. Examples The most common examples are insects that lay their eggs inside or near parasitoid larvae, which are themselves parasitizing the tissues of a host, again usually an insect larva. A well-studied case is that of the small white butterfly (''Pieris rapae''), a serious horticultural pest of ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diapause
In animal dormancy, diapause is the delay in development in response to regular and recurring periods of adverse environmental conditions.Tauber, M.J., Tauber, C.A., Masaki, S. (1986) ''Seasonal Adaptations of Insects''. Oxford University Press It is a physiological state with very specific initiating and inhibiting conditions. The mechanism is a means of surviving predictable, unfavorable environmental conditions, such as temperature extremes, drought, or reduced food availability. Diapause is observed in all the life stages of arthropods, especially insects. Embryonic diapause, a somewhat similar phenomenon, occurs in over 130 species of mammals, possibly even in humans, and in the embryos of many of the oviparous species of fish in the order Cyprinodontiformes. Activity levels of diapausing stages can vary considerably among species. Diapause may occur in a completely immobile stage, such as the pupae and eggs, or it may occur in very active stages that undergo extensive mig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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