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Diprion Similis
''Diprion similis'' is a species of sawfly in the family Diprionidae. It is native to central and northern Europe and Asia but was accidentally introduced into North America where it has become invasive. The larvae feed on the needles of pine trees, especially those of the white pine (''Pinus strobus''). In North America it is known as the introduced pine sawfly or the imported pine sawfly. It is also known as the white pine sawfly because of its preference for feeding on the white pine, but this name is confusing because another sawfly, ''Neodiprion pinetum'', whose larvae also feed on this tree, is itself known as the "white pine sawfly". Description The adult male is between in length, black apart from the underside of the abdomen which is sometimes reddish-brown. Antennae are black and bipectinate (feather-like), and legs are yellow except for the trochanters and the base of the femora which are brownish-black. The female is between long, with a black head and thorax an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theodor Hartig
Theodor Hartig (21 February 1805 – 26 March 1880) was a German forestry biologist and botanist. Biography Hartig was born in Dillenburg. He was educated in Berlin (1824–1827), and was successively lecturer and professor of forestry at the University of Berlin (1831–1838) and at the Carolinum, Braunschweig. Hartig was the first to discover and name the sieve tube element cells (as ''Siebfasern'' - sieve fibres and ''Siebröhren'' - sieve tubes) in 1837. His zoologist author abbreviation is Hartig. He described many gall wasp species. In 1842, Theodor Hartig described what is now known as the Hartig net, a network of fungal hyphae that penetrate feeder roots and surround epidermal cells. The Hartig net is part of the structure of ectomycorrizae, mutualistic symbioses between fungi and plant roots. He died in Braunschweig. Works *1836 Forstliches und forstnaturwissenschaftliches Conversations-Lexicon. Georg Ludwig Hartig and Theodor Hartig*1840. Über die Familie der Gal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinus Sylvestris
''Pinus sylvestris'', the Scots pine (UK), Scotch pine (US) or Baltic pine, is a species of tree in the pine family Pinaceae that is native to Eurasia. It can readily be identified by its combination of fairly short, blue-green leaves and orange-red bark. Description ''Pinus sylvestris'' is an evergreen coniferous tree growing up to in height and in trunk diameter when mature, exceptionally over tall and in trunk diameter on very productive sites. The tallest on record is a tree over 210 years old tree growing in Estonia which stands at . The lifespan is normally 150–300 years, with the oldest recorded specimens in Lapland, Northern Finland over 760 years. The bark is thick, flaky and orange-red when young to scaly and gray-brown in maturity, sometimes retaining the former on the upper portion.Trees for LifeSpecies profile: Scots pine/ref> The habit of the mature tree is distinctive due to its long, bare and straight trunk topped by a rounded or flat-topped mass of ... [...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'). Pheromone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pupa
A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their life cycle, the stages thereof being egg, larva, pupa, and imago. The processes of entering and completing the pupal stage are controlled by the insect's hormones, especially juvenile hormone, prothoracicotropic hormone, and ecdysone. The act of becoming a pupa is called pupation, and the act of emerging from the pupal case is called eclosion or emergence. The pupae of different groups of insects have different names such as ''chrysalis'' for the pupae of butterflies and ''tumbler'' for those of the mosquito family. Pupae may further be enclosed in other structures such as cocoons, nests, or shells. Position in life cycle The pupal stage follows the larval stage and precedes adulthood ('' imago'') in insects with complete metamo ... [...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 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ploidy
Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively, in each homologous chromosome pair, which chromosomes naturally exist as. Somatic cells, tissues, and individual organisms can be described according to the number of sets of chromosomes present (the "ploidy level"): monoploid (1 set), diploid (2 sets), triploid (3 sets), tetraploid (4 sets), pentaploid (5 sets), hexaploid (6 sets), heptaploid or septaploid (7 sets), etc. The generic term polyploid is often used to describe cells with three or more chromosome sets. Virtually all sexually reproducing organisms are made up of somatic cells that are diploid or greater, but ploidy level may vary widely between different organisms, between different tissues within the same organism, and at different stages in an organism's life cycle. Ha ... [...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] |
Arrhenotoky
Arrhenotoky (from Greek -τόκος ''-tókos'' "birth of -" + ἄρρην ''árrhēn'' "male person"), also known as arrhenotokous parthenogenesis, is a form of parthenogenesis in which unfertilized eggs develop into males. In most cases, parthenogenesis produces exclusively female offspring, hence the distinction. The set of processes included under the term arrhenotoky depends on the author: arrhenotoky may be restricted to the production of males that are haploid (haplodiploidy); may include diploid males that permanently inactivate one set of chromosomes (parahaploidy); or may be used to cover all cases of males being produced by parthenogenesis (including such cases as aphids, where the males are XO diploids). The form of parthenogenesis in which females develop from unfertilized eggs is known as thelytoky; when both males and females develop from unfertilized eggs, the term "deuterotoky" is used. In the most commonly used sense of the term, arrhenotoky is synonymous with h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinus Banksiana
Jack pine (''Pinus banksiana'') is an eastern North American pine. Its native range in Canada is east of the Rocky Mountains from the Mackenzie River in the Northwest Territories to Cape Breton Island in Nova Scotia, and the north-central and northeast of the United States from Minnesota to Maine, with the southernmost part of the range just into northwest Indiana and northwest Pennsylvania. It is also known as grey pine and scrub pine. In the far west of its range, ''Pinus banksiana'' hybridizes readily with the closely related lodgepole pine (''Pinus contorta''). The species epithet ''banksiana'' is after the English botanist Sir Joseph Banks. Description ''Pinus banksiana'' ranges from in height. Some jack pines are shrub-sized, due to poor growing conditions. They do not usually grow perfectly straight, resulting in an irregular shape similar to pitch pine (''Pinus rigida''). This pine often forms pure stands on sandy or rocky soil. It is fire-adapted to stand-rep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinus Resinosa
''Pinus resinosa'', known as red pine (also Norway pine in Minnesota), is a pine native to North America. Description Red pine is a coniferous evergreen tree characterized by tall, straight growth. It usually ranges from in height and in trunk diameter, exceptionally reaching tall. The crown is conical, becoming a narrow rounded dome with age. The bark is thick and gray-brown at the base of the tree, but thin, flaky and bright orange-red in the upper crown; the tree's name derives from this distinctive character. Some red color may be seen in the fissures of the bark. The species is self pruning; there tend not to be dead branches on the trees, and older trees may have very long lengths of branchless trunk below the canopy. The leaves are needle-like, dark yellow-green, in fascicles of two, long, and brittle. The leaves snap cleanly when bent; this character, stated as diagnostic for red pine in some texts, is however shared by several other pine species. The cones are s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinus Contorta
''Pinus contorta'', with the common names lodgepole pine and shore pine, and also known as twisted pine, and contorta pine, is a common tree in western North America. It is common near the ocean shore and in dry montane forests to the subalpine, but is rare in lowland rain forests. Like all pines (member species of the genus ''Pinus''), it is an evergreen conifer. Description Depending on subspecies, ''Pinus contorta'' grows as an evergreen shrub or tree. The shrub form is krummholz and is approximately high. The thin and narrow-crowned tree can grow high and achieve up to in diameter at chest height. The ''murrayana'' subspecies is the tallest. The crown is rounded and the top of the tree is flattened. In dense forests, the tree has a slim, conical crown. The formation of twin trees is common in some populations in British Columbia. The elastic branches stand upright or overhang and are difficult to break. The branches are covered with short shoots that are easy to remove. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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