Macrosiphum euphorbiae
Encyclopedia
Macrosiphum euphorbiae, the potato aphid
, is a sap-sucking pest insect
in the family Aphididae
. It infests potato
es and a number of other commercially important crops.
are dark at the joints between the segments and are longer than the body. They are set on outward facing tubercles. The legs are longer than in other aphids, pale green but darker at the apices. The siphunculi
are pale coloured, cylindrical with dark tips and operculi
, and are about one third the length of the body. The tail is sword-shaped and bears 6 to 12 hairs and is much shorter than the siphunculi. The winged female has a uniform darker coloured body and appendages and has a green abdomen. The nymphs are like miniature versions of the adults and go through several moults in the course of about ten days.
The green biotype is most often found on the lower, older leaves of potato plants whereas the pink biotype had no such preference. The numerical predominence of the green biotype was greater on older plants.
s, preferring plants in the Chenopodiaceae
family. In May or early June, they migrate to potato
, cabbage
, tomato
and others crop
s where they feed on shoots, the lower side of leaves, buds and flowers, often on the lower parts of the plant. They are highly polyphagous, feeding on over two hundred species in more than twenty plant families, but their preference is for plants in the Solanaceae
family. The female produces up to seventy young by parthenogenesis
over the course of three to six weeks and there may be ten generations over the summer. The optimum temperature for population increase is 68°F. When populations build up, winged individuals are produced and fly off to infest new host plants. The production of winged individuals is also dependent on the day length, the temperature, the parent type (winged or wingless) and the generation.
, parasites
and pathogen
s. Some plant varieties are more resistant to attack than others. In a study on tomatoes, it was shown that the aphids preferred smooth to hairy leaves and that susceptible tomato plants had higher sucrose
, lower quinic acid
and higher alanine
and tyrosine
levels. In lettuce, butterhead varieties are mostly moderately to highly resistant to the aphid whereas crisphead varieties are susceptible. If numbers of aphids are sufficiently high, chemical control can be attempted using insecticidal soaps. This is not always effective because the aphids usually congregate on the underside of lower leaves where they are difficult to reach with sprays.
are spread by Macrosiphum euphorbiae. These include lettuce mosaic virus
, bearded iris mosaic virus, narcissus yellow stripe virus, tulip breaking virus
, potato leaf roll virus
, potato virus Y
, beet mild yellowing virus and beet yellows virus
.
Aphid
Aphids, also known as plant lice and in Britain and the Commonwealth as greenflies, blackflies or whiteflies, are small sap sucking insects, and members of the superfamily Aphidoidea. Aphids are among the most destructive insect pests on cultivated plants in temperate regions...
, is a sap-sucking pest insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
in the family Aphididae
Aphididae
Aphididae is a very large insect family in the aphid superfamily , of the order Hemiptera. There are several thousand species in this family, many of which are well known for being serious plant pests...
. It infests potato
Potato
The potato is a starchy, tuberous crop from the perennial Solanum tuberosum of the Solanaceae family . The word potato may refer to the plant itself as well as the edible tuber. In the region of the Andes, there are some other closely related cultivated potato species...
es and a number of other commercially important crops.
Distribution
Macrosiphum euphorbiae originated in North America but it has spread to the temperate parts of Europe and Asia and is found in all areas in which potatoes are grown.Description
The wingless female potato aphid is green or occasionally pink, often with a darker dorsal stripe. It has a pear-shaped body reaching about four millimetres long. The antennaeAntenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
are dark at the joints between the segments and are longer than the body. They are set on outward facing tubercles. The legs are longer than in other aphids, pale green but darker at the apices. The siphunculi
Cornicle
The cornicle is one of a pair of small upright backward-pointing tubes found on the dorsal side of the last segment of the bodies of aphids. They are sometimes mistaken for cerci...
are pale coloured, cylindrical with dark tips and operculi
Operculum
Operculum may refer to:*Operculum , a stiff structure resembling a lid or a small door that opens and closes**Operculum , a lid on the shell of some gastropods**Operculum , a lid on the orifice of some bryozoans...
, and are about one third the length of the body. The tail is sword-shaped and bears 6 to 12 hairs and is much shorter than the siphunculi. The winged female has a uniform darker coloured body and appendages and has a green abdomen. The nymphs are like miniature versions of the adults and go through several moults in the course of about ten days.
The green biotype is most often found on the lower, older leaves of potato plants whereas the pink biotype had no such preference. The numerical predominence of the green biotype was greater on older plants.
Biology
Female potato aphids overwinter on weeds, the sprouts of potatoes in storage and on lettuce under glass. They usually emerge in April and begin feeding on perennial weedWeed
A weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...
s, preferring plants in the Chenopodiaceae
Chenopodiaceae
Chenopodiaceae were a family of flowering plants, also called the Goosefoot Family. They are now included within family Amaranthaceae. The vast majority of Chenopods are weeds, and many are salt and drought tolerant. A few food crops also belong to the family: spinach, beets, chard, quinoa, and...
family. In May or early June, they migrate to potato
Potato
The potato is a starchy, tuberous crop from the perennial Solanum tuberosum of the Solanaceae family . The word potato may refer to the plant itself as well as the edible tuber. In the region of the Andes, there are some other closely related cultivated potato species...
, cabbage
Cabbage
Cabbage is a popular cultivar of the species Brassica oleracea Linne of the Family Brassicaceae and is a leafy green vegetable...
, tomato
Tomato
The word "tomato" may refer to the plant or the edible, typically red, fruit which it bears. Originating in South America, the tomato was spread around the world following the Spanish colonization of the Americas, and its many varieties are now widely grown, often in greenhouses in cooler...
and others crop
Crop
Crop may refer to:* Crop, a plant grown and harvested for agricultural use* Crop , part of the alimentary tract of some animals* Crop , a modified whip used in horseback riding or disciplining humans...
s where they feed on shoots, the lower side of leaves, buds and flowers, often on the lower parts of the plant. They are highly polyphagous, feeding on over two hundred species in more than twenty plant families, but their preference is for plants in the Solanaceae
Solanaceae
Solanaceae are a family of flowering plants that include a number of important agricultural crops as well as many toxic plants. The name of the family comes from the Latin Solanum "the nightshade plant", but the further etymology of that word is unclear...
family. The female produces up to seventy young by parthenogenesis
Parthenogenesis
Parthenogenesis is a form of asexual reproduction found in females, where growth and development of embryos occur without fertilization by a male...
over the course of three to six weeks and there may be ten generations over the summer. The optimum temperature for population increase is 68°F. When populations build up, winged individuals are produced and fly off to infest new host plants. The production of winged individuals is also dependent on the day length, the temperature, the parent type (winged or wingless) and the generation.
Management
Various factors influence aphid populations. High temperatures or heavy rainfall may reduce infestations and the numbers are naturally controlled by predatorsPredation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
, parasites
Parasitism
Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...
and pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
s. Some plant varieties are more resistant to attack than others. In a study on tomatoes, it was shown that the aphids preferred smooth to hairy leaves and that susceptible tomato plants had higher sucrose
Sucrose
Sucrose is the organic compound commonly known as table sugar and sometimes called saccharose. A white, odorless, crystalline powder with a sweet taste, it is best known for its role in human nutrition. The molecule is a disaccharide composed of glucose and fructose with the molecular formula...
, lower quinic acid
Quinic acid
Quinic acid is a cyclitol, a cyclic polyol. It is a crystalline acid obtained from cinchona bark, coffee beans, and other plant products and made synthetically by hydrolysis of chlorogenic acid. Quinic acid is also implicated in the perceived acidity of coffee...
and higher alanine
Alanine
Alanine is an α-amino acid with the chemical formula CH3CHCOOH. The L-isomer is one of the 20 amino acids encoded by the genetic code. Its codons are GCU, GCC, GCA, and GCG. It is classified as a nonpolar amino acid...
and tyrosine
Tyrosine
Tyrosine or 4-hydroxyphenylalanine, is one of the 22 amino acids that are used by cells to synthesize proteins. Its codons are UAC and UAU. It is a non-essential amino acid with a polar side group...
levels. In lettuce, butterhead varieties are mostly moderately to highly resistant to the aphid whereas crisphead varieties are susceptible. If numbers of aphids are sufficiently high, chemical control can be attempted using insecticidal soaps. This is not always effective because the aphids usually congregate on the underside of lower leaves where they are difficult to reach with sprays.
Disease spread
A number of virus diseasesPlant virus
Plant viruses are viruses that affect plants. Like all other viruses, plant viruses are obligate intracellular parasites that do not have the molecular machinery to replicate without a host. Plant viruses are pathogenic to higher plants...
are spread by Macrosiphum euphorbiae. These include lettuce mosaic virus
Lettuce mosaic virus
Lettuce mosaic virus is a typical potyvirus , which causes one of the major virus diseases of lettuce crops worldwide....
, bearded iris mosaic virus, narcissus yellow stripe virus, tulip breaking virus
Tulip breaking virus
The Tulip breaking virus, also known as the "Tulip break virus", "Tulip breaking potyvirus", "Lily streak virus", "Tulip mosaic virus", "Lily mottle virus", "Lily mosaic virus", or simply "TBV" is a plant virus that is most famous for its infection of tulips...
, potato leaf roll virus
Potato leaf roll virus
Potato leafroll virus is a member of the genus Polerovirus and family Luteoviridae. The phloem limited positive sense RNA virus infects potatos and other members of the family Solanaceae. PLRV was first described by Quanjer et. al. in 1916. PLRV is transmitted by aphids, primarily the green...
, potato virus Y
Potato virus Y
Potato virus Y is a plant pathogenic virus of the family Potyviridae, and one of the most important plant viruses affecting potato production....
, beet mild yellowing virus and beet yellows virus
Beet yellows virus
Beet yellows virus is a plant pathogenic virus of the family Closteroviridae. Beet yellows virus is transmitted by multiple species of aphid and causes a yellowing disease in Beta vulgaris and Spinacia oleracea.-External links:**...
.