Chromosomal crossover, or crossing over, is the exchange of genetic material during sexual reproduction between two homologous chromosomes' non-sister chromatids that results in recombinant chromosomes. It is one of the final phases of genetic recombination, which occurs in the pachytene stage of prophase I of meiosis during a process called synapsis. Synapsis begins before the synaptonemal complex develops and is not completed until near the end of prophase I. Crossover usually occurs when matching regions on matching chromosomes break and then reconnect to the other chromosome.
The Rocky Mountain locust is an extinct species of grasshopper that ranged through the western half of the United States and some western portions of Canada with large numbers seen until the end of the 19th century. Sightings often placed their swarms in numbers far larger than any other locust species, with one famous sighting in 1875 estimated at 198,000 square miles (510,000 km2) in size, weighing 27.5 million tons and consisting of some 12.5 trillion insects, the greatest concentration of animals ever speculatively guessed, according to Guinness World Records.
Grasshoppers are a group of insects belonging to the suborder Caelifera. They are amongst what are possibly the most ancient living groups of chewing herbivorous insects, dating back to the early Triassic around 250 million years ago.
The migratory locust is the most widespread locust species, and the only species in the genus Locusta. It occurs throughout Africa, Asia, Australia and New Zealand. It used to be common in Europe but has now become rare there. Because of the vast geographic area it occupies, which comprises many different ecological zones, numerous subspecies have been described. However, not all experts agree on the validity of some of these subspecies.
Melanoplus is a large genus of grasshoppers. They are the typical large grasshoppers in North America. A common name is spur-throat grasshoppers, but this more typically refers to members of the related subfamily Catantopinae.
Romalea is a genus of grasshoppers native to the Southeastern and South-central United States. As traditionally defined, it contains a single species, Romalea microptera, known commonly as the Georgia Thumper,eastern lubber grasshopper, Florida lubber, or Florida lubber grasshopper, although some recent authorities regard Taeniopoda as a junior synonym, in which case there are about a dozen Romalea species in southern United States, Mexico and Central America.
Chorthippus brunneus, also known as the common field grasshopper, is a species of grasshopper of the subfamily Gomphocerinae. The species is common and widespread in the Western Palearctic, and the IUCN lists it as Least Concern.
The differential grasshopper is a species of grasshopper belonging to the genus Melanoplus. It is found throughout northern Mexico, the central United States and southern Ontario, Canada. It is considered a pest over most of its range.
In genetics, a chiasma is the point of contact, the physical link, between two (non-sister) chromatids belonging to homologous chromosomes. At a given chiasma, an exchange of genetic material can occur between both chromatids, what is called a chromosomal crossover, but this is much more frequent during meiosis than mitosis. In meiosis, absence of a chiasma generally results in improper chromosomal segregation and aneuploidy.
Metarhizium acridum is the new name given to a group of fungal isolates that are known to be virulent and specific to the Acrididea (grasshoppers). Previously, this species has had variety status in Metarhizium anisopliae ; before that, reference had been made to M. flavoviride or Metarhizium sp. describing an "apparently homologous and distinctive group" of isolates that were most virulent against Schistocerca gregaria in early screening bioassays.
Melanoplus bivittatus, the two-striped grasshopper, is a poikilothermic species of grasshopper belonging to the genus Melanoplus. It is commonly found in North America, with high quantities inhabiting Canadian prairies and farmland.
Streptanthus polygaloides is a species of flowering plant in the mustard family known by the common name milkwort jewelflower. It is endemic to the Sierra Nevada foothills of California, where it grows in woodlands and chaparral, generally on serpentine soils.
Tropidacris collaris, the blue-winged grasshopper or violet-winged grasshopper, is a large South American species of grasshopper in the family Romaleidae. As suggested by its name, in flight the wings are usually conspicuously blue, but they can occasionally be grayish or greenish. Adult males are typically 5–7 cm (2.0–2.8 in) long and females typically 8.5–10.5 cm (3.3–4.1 in) long; the wingspan is usually about 18 cm (7 in). The gregarious and flightless nymphs are aposematically colored in black, red and yellow and are presumed to be toxic; a researcher who tasted one noted that it was very bitter, similar to a monarch butterfly.
Poekilocerus pictus, the painted grasshopper, aak grasshopper or ak grasshopper, is a fairly large and brightly coloured species of grasshopper found in India, Pakistan and Afghanistan, especially in drier regions. Both adults and nymphs are toxic; the nymphs are notorious for being able to squirt a jet of noxious liquid at up to around 30 cm (1 ft) away when grasped.
Mermis nigrescens is a species of nematode known commonly as the grasshopper nematode. It is distributed in the Americas, Europe, and Asia. It occurs in Tasmania, but it has not been observed on mainland Australia. It has been rarely observed in Africa. It is a parasite of insects, especially grasshoppers.
Tropidacris is a Neotropical genus of grasshopper in the family Romaleidae. They are among the largest grasshoppers in the world by length and wingspan, reaching up to 14.5 cm (5.7 in) and 24 cm (9.4 in) respectively. They are variably colored in green, brown, black, reddish or yellowish, and have wings that usually are conspicuously blue or red in flight. The gregarious and flightless nymphs have bright aposematic colors and are presumed to be toxic; a researcher who tasted one noted that it was very bitter, similar to a monarch butterfly.
Cornops aquaticum is a semiaquatic species of grasshopper native to the Neotropics, from southern Mexico south to central Argentina and Uruguay. It feeds and breeds exclusively on members of the aquatic plant family Pontederiaceae, especially water hyacinth, and is being investigated as a possible biological pest control agent for the water hyacinth in countries where that plant is invasive.
Melanoplus bispinosus, the two-spined spurthroated grasshopper, is a species of grasshopper belonging to the genus Melanoplus. This grasshopper is native to the United States.
Eyprepocnemis plorans, the lamenting grasshopper, is a species of insect in the family Acrididae. It is the type species of the genus Eyprepocnemis, and is found in Africa, parts of the Middle East, and southern Europe. It typically inhabits wetlands and other moist habitats.
Tropidacris cristata, the giant red-winged grasshopper, is a widespread species of lubber grasshopper in the family Romaleidae from tropical South and Central America, and Mexico. It is among the largest grasshoppers in the world by length and wingspan, reaching up to 14.5 cm (5.7 in) and 24 cm (9.4 in) respectively. More typical adult lengths are 5.5–7 cm (2.2–2.8 in), average 6.5 cm (2.6 in), in males and 7–12 cm (2.8–4.7 in), average 11 cm (4.3 in), in females. As suggested by the common name, adult T. cristata have conspicuously red wings in flight, although the exact red hue varies. The flightless and gregarious nymphs have aposematic dark-and-yellow stripes and are presumed to be toxic.
