Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the full set of genes of their single parent and thus the newly created individual is genetically and physically similar to the parent or an exact clone of the parent. Asexual reproduction is the primary form of reproduction for single-celled organisms such as archaea and bacteria. Many eukaryotic organisms including plants, animals, and fungi can also reproduce asexually. In vertebrates, the most common form of asexual reproduction is parthenogenesis, which is typically used as an alternative to sexual reproduction in times when reproductive opportunities are limited. Komodo dragons and some monitor lizards can reproduce asexually.
Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A typical life cycle involves flightless females giving live birth to female nymphs—who may also be already pregnant, an adaptation scientists call telescoping generations—without the involvement of males. Maturing rapidly, females breed profusely so that the number of these insects multiplies quickly. Winged females may develop later in the season, allowing the insects to colonize new plants. In temperate regions, a phase of sexual reproduction occurs in the autumn, with the insects often overwintering as eggs.
Hemiptera is an order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, assassin bugs, bed bugs, and shield bugs. They range in size from 1 mm (0.04 in) to around 15 cm (6 in), and share a common arrangement of piercing-sucking mouthparts. The name "true bugs" is often limited to the suborder Heteroptera.
Scale insects are small insects of the order Hemiptera, suborder Sternorrhyncha. Of dramatically variable appearance and extreme sexual dimorphism, they comprise the infraorder Coccomorpha which is considered a more convenient grouping than the superfamily Coccoidea due to taxonomic uncertainties. Adult females typically have soft bodies and no limbs, and are concealed underneath domed scales, extruding quantities of wax for protection. Some species are hermaphroditic, with a combined ovotestis instead of separate ovaries and testes. Males, in the species where they occur, have legs and sometimes wings, and resemble small flies. Scale insects are herbivores, piercing plant tissues with their mouthparts and remaining in one place, feeding on sap. The excess fluid they imbibe is secreted as honeydew on which sooty mold tends to grow. The insects often have a mutualistic relationship with ants, which feed on the honeydew and protect them from predators. There are about 8,000 described species.
The Aphididae are a very large insect family in the aphid superfamily (Aphidoidea), of the order Hemiptera. These insects suck the sap from plant leaves. Several thousand species are placed in this family, many of which are considered plant/crop pests. They are the family of insects containing most plant virus vectors with the green peach aphid being one of the most prevalent and indiscriminate carriers.
Blissus leucopterus, also known as the true chinch bug, is a small North American insect in the order Hemiptera and family Blissidae. It is the most commonly encountered species of the genus Blissus, which are all known as chinch bugs. A closely related species is B. insularis, the southern chinch bug.
The Russian wheat aphid is an aphid that can cause significant losses in cereal crops. The species was introduced to the United States in 1986 and is considered an invasive species there. This aphid is pale green and up to 2 mm long. Cornicles are very short, rounded, and appear to be lacking. There is an appendage above the cauda giving the aphid the appearance of having two tails. The saliva of this aphid is toxic to the plant and causes whitish striping on cereal leaves. Feeding by this aphid will also cause the flag leaf to turn white and curl around the head causing incomplete head emergence. Its host plants are cereal grain crops including wheat and barley and to a lesser extent, wild grasses such as wheatgrasses, brome-grasses, ryegrasses and anything in the grass family.
Parthenogenesis is a natural form of asexual reproduction in which growth and development of embryos occur in a gamete without combining with another gamete. 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.
Coccinellidae is a widespread family of small beetles. They are commonly known as ladybugs in North America and ladybirds in the United Kingdom; "lady" refers to mother Mary. Entomologists use the names ladybird beetles or lady beetles to avoid confusion with true bugs. The more than 6,000 described species have a global distribution and are found in a variety of habitats. They are oval beetles with a domed back and flat underside. Many of the species have conspicuous aposematic (warning) colours and patterns, such as red with black spots, that warn potential predators that they taste bad.
The soybean aphid is an insect pest of soybean that is exotic to North America. The soybean aphid is native to Asia. It has been described as a common pest of soybeans in China and as an occasional pest of soybeans in Indonesia, Japan, Korea, Malaysia, the Philippines, and Thailand. The soybean aphid was first documented in North America in Wisconsin in July 2000. Ragsdale et al. (2004) noted that the soybean aphid probably arrived in North America earlier than 2000, but remained undetected for a period of time. Venette and Ragsdale (2004) suggested that Japan probably served as the point of origin for the soybean aphid's North American invasion. By 2003, the soybean aphid had been documented in Delaware, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New York, North Dakota, Ohio, Pennsylvania, South Dakota, Virginia, West Virginia, and Wisconsin. Together, these states accounted for 89% of the 63,600,000 acres (257,000 km2) of soybean planted in the United States in 2007.
Myzus persicae, known as the green peach aphid, greenfly, or the peach-potato aphid, is a small green aphid belonging to the order Hemiptera. It is the most significant aphid pest of peach trees, causing decreased growth, shrivelling of the leaves and the death of various tissues. It also acts as a vector for the transport of plant viruses such as cucumber mosaic virus (CMV), potato virus Y (PVY) and tobacco etch virus (TEV). Potato virus Y and potato leafroll virus can be passed to members of the nightshade/potato family (Solanaceae), and various mosaic viruses to many other food crops.
Macrosiphum rosae, the rose aphid, is a species of sap-sucking aphids in the subfamily Aphidinae. They have a world-wide distribution and infest rosebushes as the main host in spring and early summer, congregating on the tips of shoots and around new buds. Later in the summer, winged forms move to other rose bushes, or to a limited number of secondary hosts, before returning to rosebushes to lay eggs in the autumn.
The black bean aphid is a small black insect in the genus Aphis, with a broad, soft body, a member of the order Hemiptera. Other common names include blackfly, bean aphid, and beet leaf aphid. In the warmer months of the year, it is found in large numbers on the undersides of leaves and on the growing tips of host plants, including various agricultural crops and many wild and ornamental plants. Both winged and wingless forms exist, and at this time of year, they are all females. They suck sap from stems and leaves and cause distortion of the shoots, stunted plants, reduced yield, and spoiled crops. This aphid also acts as a vector for viruses that cause plant disease, and the honeydew it secretes may encourage the growth of sooty mould. It breeds profusely by live birth, but its numbers are kept in check, especially in the later part of the summer, by various predatory and parasitic insects. Ants feed on the honeydew it produces, and take active steps to remove predators. It is a widely distributed pest of agricultural crops and can be controlled by chemical or biological means. In the autumn, winged forms move to different host plants, where both males and females are produced. These mate and the females lay eggs which overwinter.
Acyrthosiphon pisum, commonly known as the pea aphid, is a sap-sucking insect in the family Aphididae. It feeds on several species of legumes worldwide, including forage crops, such as pea, clover, alfalfa, and broad bean, and ranks among the aphid species of major agronomical importance. The pea aphid is a model organism for biological study whose genome has been sequenced and annotated.
Rhopalosiphum maidis, common names corn leaf aphid and corn aphid, is an insect, and a pest of maize and other crops. It has a nearly worldwide distribution and is typically found in agricultural fields, grasslands, and forest-grassland zones. Among aphids that feed on maize, it is the most commonly encountered and most economically damaging, particularly in tropical and warmer temperate areas. In addition to maize, R. maidis damages rice, sorghum, and other cultivated and wild monocots.
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.
The greenbug, or wheat aphid, is an aphid in the superfamily Aphidoidea in the order Hemiptera. It is a true bug and feeds on the leaves of Gramineae (grass) family members.
Sitobion lambersi, also known as Sitobion (Sitobion) lambersi, is an aphid in the superfamily Aphidoidea in the order Hemiptera. It is a true bug and sucks sap from plants.
The Indian grain aphid, also known as Sitobion (Sitobion) miscanthi, is an aphid in the superfamily Aphidoidea in the order Hemiptera. It is a true bug and sucks sap from cereal plants, making it a pest of wheat production. It has also been recorded as a pest of finger millet, sorghum, and pearl millet in South Asia.
Sitobion is a genus of aphids in the family Aphididae. There are more than 80 described species in Sitobion.
