An antiphon is a short chant in Christian ritual, sung as a refrain. The texts of antiphons are the Psalms, their form was favored by St Ambrose and they feature prominently in Ambrosian chant, but they are used in Gregorian chant as well. They may be used for the Introit, the Offertory or the Communion, they may be used in the Liturgy of the Hours for Lauds or Vespers. They should not be confused with processional antiphons; when a chant consists of alternating verses and responds, a refrain is needed. The looser term antiphony is used for any call and response style of singing, such as the kirtan or the sea shanty and other work songs, songs and worship in African and African-American culture. Antiphonal music is that performed by two choirs in interaction singing alternate musical phrases. Antiphonal psalmody is the singing or musical playing of psalms by alternating groups of performers; the term “antiphony” can refer to a choir-book containing antiphons. The chant of early Christianity through to the end of the 5th century had its root in the Synagogue, from whence early Christians borrowed the traditions of the chanting of psalms, singing of hymns and cantillation.

There is some evidence from Acts of the Apostles that early Christians stayed close to contemporary Jewish traditions, for example Acts 2:46-47 states that "with one accord in the Temple, breaking bread from house to house did eat their meat with gladness and singleness of heart, praising God, having favour with all the people". Socrates of Constantinople wrote that antiphony was introduced into Christian worship by Ignatius of Antioch after he saw a vision of two choirs of angels. Antiphonal singing was an element of Jewish liturgy believed to have entered the monasteries of Syria and Palestine in the 4th century from the Jewish communities such as the one in Antioch. Antiphons have remained an integral part of the worship in the Armenian Rite; the practice did not become part of the Latin Church until more than two centuries later. Ambrose and Gregory the Great, who are known for their contributions to the formulation of Gregorian chant, are credited with'antiphonaries', collections of works suitable for antiphon, which are still used in the Roman Catholic Church today.

Polyphonic Marian antiphons emerged in England in the 14th century as settings of texts honouring the Virgin Mary, which were sung separately from the mass and office after Compline. Towards the end of the 15th century, English composers produced expanded settings up to nine parts, with increasing complexity and vocal range; the largest collection of such antiphons is the late-15th-century Eton Choirbook. As a result, antiphony remains common in the Anglican musical tradition: the singers face each other, placed in the quire's Decani and Cantoris; the Greater Advent or O Antiphons are antiphons used at daily prayer in the evenings of the last days of Advent in various liturgical Christian traditions. Each antiphon is a name of one of his attributes mentioned in Scripture. In the Roman Catholic tradition, they are sung or recited at Vespers from December 17 to December 23. In the Church of England they have traditionally been used as antiphons to the Magnificat at Evening Prayer. More they have found a place in primary liturgical documents throughout the Anglican Communion, including the Church of England's Common Worship liturgy.

Use of the O Antiphons was preserved in Lutheranism at the German Reformation, they continue to be sung in Lutheran churches. When two or more groups of singers sing in alternation, the style of music can be called polychoral; this term is applied to music of the late Renaissance and early Baroque periods. Polychoral techniques are a definitive characteristic of the music of the Venetian school, exemplified by the works of Giovanni Gabrieli: this music is known as the Venetian polychoral style; the Venetian polychoral style was an important innovation of the late Renaissance. This style, with its variations as it spread across Europe after 1600, helped to define the beginning of the Baroque era. Polychoral music was not limited to Italy in the Renaissance. There are examples from the 19th and 20th centuries, from composers as diverse as Hector Berlioz, Igor Stravinsky, Béla Bartók, Karlheinz Stockhausen. Marian antiphon Polyphony Polyphonic form Polyphonic singing Polychoral compositions Latin church music by George Frideric Handel — includes three antiphons.

Antiphon "O Sapientia quae ex ore Altissimi..." Antiphon O Adonai II Great Advent Antiphon File:Schola Gregoriana-Antiphona et Magnificat.ogg

Plagiolepis alluaudi, the little yellow ant, is a species of Plagiolepis. The species is native to Madagascar, an island off the coast of East Africa, it is known to be a widespread invasive species. In an effort to distinguish its name from other small and yellow species of ant it may be called Alluaud's little yellow ant, after Charles A. Alluaud. Plagiolepis alluaudi is a small ant averaging 1⁄16 of an inch in total length, it is yellow in color, has a rounded head, has eleven antennal segments. The only other yellow ant in the genus Plagiolepis is P. exigua. P. alluaudi may be confused with workers of the genus Brachymyrmex, which have nine antennal segments. Plagiolepis alluaudi consumes honeydew, a product of plant sap, produced by insects such as aphids and scale insects. P. alluaudi is known to protect these insect species—which are agricultural pests—from predators, going so far as to raise the pests' offspring in their nest until the larvae reach adulthood. Colonies of P. alluaudi contain thousands of egg-laying queen ants.

Plagiolepis alluaudi is not known to sting humans. However, it can be a threat to agricultural crops, such as citrus, by protecting other insect species that transmit disease. P. alluaudi may enter human homes to eat sweet foods. Established colonies are difficult to eradicate, but placing ant baits outside may eliminate parts of a large colony at one time. Plagiolepis alluaudi is introduced on land to which they are not native via shipping lanes, it has been documented in England, Switzerland, the Pacific Islands, Catalina Island and the Caribbean. P. alluaudi is considered a pest in European greenhouses. In 2017, established colonies of the species were found in Florida; the species will thrive there due to the warm and moist climate of South Florida. Fleshler, David. "Nasty little yellow ant establishes first U. S. colonies in Fort Lauderdale". Sun-Sentinel. Retrieved 2017-11-16. Wetterer, James K. "Worldwide spread of Alluaud's little yellow ant, Plagiolepis alluaudi". Myrmecol. News. 19: 53–59. ISSN 1994-4136.

Retrieved 2017-11-16 – via ResearchGate. Media related to Plagiolepis alluaudi at Wikimedia Commons

Nephrolepis cordifolia, is a fern native to northern Australia and Asia. It has many common names including fishbone fern,tuberous sword fern,tuber ladder fern, erect sword fern, narrow sword fern and ladder fern, herringbone fern, it is indigenous to the Hawaiian Islands where it is known as kupukupu, okupukupu or ni'ani'au It is similar to the related fern Nephrolepis exaltata. It has been introduced into Bermuda, French Polynesia, New Zealand, the United States; the species is native in north-eastern Australia, is considered naturalised on the central east coast of New South Wales. Nephrolepis cordifolia has become. In New Zealand it is listed on the National Pest Plant Accord, which prohibits the sale and distribution of the plant, it is listed as an invasive species in United States. Nephrolepis cordifolia at the Global Invasive Species Database "Nephrolepis cordifolia". Integrated Taxonomic Information System. Retrieved 2011-11-07. Nephrolepis cordifolia at Weedbusters Nephrolepis cordifolia at the Center for Invasive Species and Ecosystem Health