In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different varieties, species or genera through sexual reproduction. Generally, it means that each cell has genetic material from two different organisms, whereas an individual where some cells are derived from a different organism is called a chimera. Hybrids are not always intermediates between their parents, but can show hybrid vigor, sometimes growing larger or taller than either parent. The concept of a hybrid is interpreted differently in animal and plant breeding, where there is interest in the individual parentage. In genetics, attention is focused on the numbers of chromosomes. In taxonomy, a key question is how closely related the parent species are.
Tilapia is the common name for nearly a hundred species of cichlid fish from the coelotilapine, coptodonine, heterotilapine, oreochromine, pelmatolapiine, and tilapiine tribes, with the economically most important species placed in the Coptodonini and Oreochromini. Tilapia are mainly freshwater fish inhabiting shallow streams, ponds, rivers, and lakes, and less commonly found living in brackish water. Historically, they have been of major importance in artisanal fishing in Africa, and they are of increasing importance in aquaculture and aquaponics. Tilapia can become a problematic invasive species in new warm-water habitats such as Australia, whether deliberately or accidentally introduced, but generally not in temperate climates due to their inability to survive in cold water.
An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there by human activity, directly or indirectly, and either deliberately or accidentally. Non-native species can have various effects on the local ecosystem. Introduced species that become established and spread beyond the place of introduction are considered naturalized. The process of human-caused introduction is distinguished from biological colonization, in which species spread to new areas through "natural" (non-human) means such as storms and rafting. The Latin expression neobiota captures the characteristic that these species are new biota to their environment in terms of established biological network relationships. Neobiota can further be divided into neozoa and neophyta (plants).
Tsuga canadensis, also known as eastern hemlock, eastern hemlock-spruce, or Canadian hemlock, and in the French-speaking regions of Canada as pruche du Canada, is a coniferous tree native to eastern North America. It is the state tree of Pennsylvania. Eastern hemlocks are widespread throughout much of the Great Lakes region, the Appalachian Mountains, the Northeastern United States, and Maritime Canada. They have been introduced in the United Kingdom and mainland Europe, where they are used as ornamental trees.
The winter moth is a moth of the family Geometridae. It is an abundant species of Europe and the Near East and a famous study organism for evaluating insect population dynamics. It is one of very few lepidopterans of temperate regions in which adults are active in late autumn and early winter. The adults use endothermy for movement in these cold temperatures. The female of this species is virtually wingless and cannot fly, but the male is fully winged and flies strongly. After the initial frosts of late fall, the females emerge from their pupa, walk to and up trees, there emitting pheromones in the evening to attract males. Fertilized, she ascends to lay, on average, around 100 eggs. Typically, the larger the female moth is the more eggs she lays.
Derodontidae is a family of beetles, in its own superfamily, Derodontoidea, sometimes known as the tooth-necked fungus beetles. Beetles of this family are small, between 2 and 6 mm in length, typically with spiny margins on their pronotum that give them their name, though the genus Laricobius lacks these spines. Unusual among beetles, they have two ocelli on the top of their heads.
The hemlock woolly adelgid, or HWA, is an insect of the order Hemiptera native to East Asia. It feeds by sucking sap from hemlock and spruce trees. In its native range, HWA is not a serious pest because populations are managed by natural predators and parasitoids and by host resistance. In eastern North America it is a destructive pest that threatens the eastern hemlock and the Carolina hemlock. HWA is also found in western North America, where it has likely been present for thousands of years. In western North America, it primarily attacks western hemlock Tsuga heterophylla and has only caused minor damage due to natural predators and host resistance. Accidentally introduced to North America from Japan, HWA was first found in the eastern United States near Richmond, Virginia, in 1951. The pest is now found from northern Georgia to coastal Maine and southwestern Nova Scotia. As of 2015, 90% of the geographic range of eastern hemlock in North America has been affected by HWA.
Myriophyllum spicatum is native to Europe, Asia, and north Africa, but has a wide geographic and climatic distribution among some 57 countries, extending from northern Canada to South Africa. It is a submerged aquatic plant, grows in still or slow-moving water, and is considered to be a highly invasive species.
Hybrid speciation is a form of speciation where hybridization between two different species leads to a new species, reproductively isolated from the parent species. Previously, reproductive isolation between two species and their parents was thought to be particularly difficult to achieve, and thus hybrid species were thought to be very rare. With DNA analysis becoming more accessible in the 1990s, hybrid speciation has been shown to be a somewhat common phenomenon, particularly in plants. In botanical nomenclature, a hybrid species is also called a nothospecies. Hybrid species are by their nature polyphyletic.
Laricobius is a genus of beetles in the family Derodontidae, the tooth-necked fungus beetles.
Phylloxeridae is a small family of plant-parasitic hemipterans closely related to aphids with only 75 described species. This group comprises two subfamilies and 11 genera with one that is fossil. The genus type is Phylloxera. The Phylloxeridae species are usually called phylloxerans or phylloxerids.
Dendrodrilus rubidus is a species of earthworm in the family Lumbricidae. It is native to Europe, and it is a widespread introduced species, occurring on every continent except Antarctica, as well as many islands. It is often invasive. It is sometimes used as fishing bait, and is marketed under many nonspecific names, including red wiggler, jumping red wiggler, red trout worm, jumbo red worm, and pink worm. Other common names include bank worm, tree worm, and gilt tail.
Laricobius osakensis is a species of Derodontid beetle native to Japan. Described in 2011, it feeds exclusively on hemlock woolly adelgid, an invasive insect species that is destroying huge numbers of hemlock trees in eastern North America. It has shown promise as a biological control agent in field trials.
Scymnus coniferarum, the conifer lady beetle, is a species of dusky lady beetle in the family Coccinellidae. It is found in western North America.
Laricobius nigrinus is a species of tooth-necked fungus beetle in the family Derodontidae. It is native to western North America, and it is being studied as a biological control agent for the hemlock woolly adelgid. It was first released in 2003 and continues to be reared and released across the Northeast to control infestations.
Allonemobius fasciatus, commonly known as the striped ground cricket, is an omnivorous species of cricket that belongs to the subfamily Nemobiinae. A. fasciatus is studied in depth in evolutionary biology because of the species's ability to hybridize with another Allonemobius species, A. socius.
Laricobius erichsoni is a species of tooth-necked fungus beetle in the family Derodontidae. It is found in Europe and Northern Asia and North America.
Bradycellus nigrinus is a species of ground beetle in the family Carabidae. It is found in North America.
Sasajiscymnus tsugae, formerly Pseudoscymnus tsugae, is a species of insect in the family Coccinellidae. It feeds on the hemlock woolly adelgid.
