''Macrosteles quadrilineatus'', the aster leafhopper or six-spotted leafhopper, is a leafhopper species in the genus '' Macrosteles'', found in the United States. It is the vector of

aster yellows Aster yellows is a chronic, systemic plant disease caused by several bacteria called phytoplasma. The aster yellows phytoplasma (AYP) affects 300 species in 38 families of broad-leaf herbaceous plants, primarily in the aster family, as well as im ...

disease, which affects various vegetable plants, weeds and ornamental plants.

Description

The aster leafhopper is a small species, with males reaching about in length and females about . The fore-wings are greyish-green while the abdomen is yellowish-green. Six pairs of minute black spots or streaks on the head give the insect its alternative name of six-spotted leafhopper.

Ecology

In the United States, strong southerly winds in the spring carry adults northwards to the Mid West and northern parts of the country, and these insects usually arrive earlier and exceed in number the resident insects that have been overwintering there, mostly on grasses and cereals. Eggs are laid on a wide range of host plants which include

grass Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns an ...

es and

clover Clover or trefoil are common names for plants of the genus ''Trifolium'' (from Latin ''tres'' 'three' + ''folium'' 'leaf'), consisting of about 300 species of flowering plants in the legume or pea family Fabaceae originating in Europe. The genus ...

corn Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. Th ...

oat The oat (''Avena sativa''), sometimes called the common oat, is a species of cereal grain grown for its seed, which is known by the same name (usually in the plural, unlike other cereals and pseudocereals). While oats are suitable for human con ...

s, rye,

carrot The carrot ('' Daucus carota'' subsp. ''sativus'') is a root vegetable, typically orange in color, though purple, black, red, white, and yellow cultivars exist, all of which are domesticated forms of the wild carrot, ''Daucus carota'', nat ...

s and various weeds. The eggs hatch in about one week and the whole life cycle takes about four weeks. Carrot,

dill Dill (''Anethum graveolens'') is an annual herb in the celery family Apiaceae. It is the only species in the genus ''Anethum''. Dill is grown widely in Eurasia, where its leaves and seeds are used as a herb or spice for flavouring food. Growth ...

potato The potato is a starchy food, a tuber of the plant ''Solanum tuberosum'' and is a root vegetable native to the Americas. The plant is a perennial in the nightshade family Solanaceae. Wild potato species can be found from the southern Unit ...

and

radish The radish (''Raphanus raphanistrum'' subsp. ''sativus'') is an Eating, edible root vegetable of the family Brassicaceae that was domesticated in Asia prior to Roman Empire, Roman times. Radishes are grown and consumed throughout the world, be ...

are selected by adults for feeding purposes but are not good for breeding purposes. The leafhopper is attacked by several

parasitoid In evolutionary ecology, a parasitoid is an organism that lives in close association with its host (biology), host at the host's expense, eventually resulting in the death of the host. Parasitoidism is one of six major evolutionarily stable str ...

s including '' Pachygonatopus minimus'', '' Neogonatopus ombrodes'' and '' Epigonatopus plesius''.

Aster yellows

Aster yellows is a disease of various vegetable crops, weeds and ornamental plants and is transmitted almost entirely by the aster leafhopper. The disease is caused by

phytoplasma Phytoplasmas are obligate intracellular parasites of plant phloem tissue and of the insect vectors that are involved in their plant-to-plant transmission. Phytoplasmas were discovered in 1967 by Japanese scientists who termed them mycoplasma-lik ...

s, specialised bacteria that are obligate parasites of plant tissue. The symptoms shown by the plant are a yellowing of the leaf veins followed by yellowing of the leaf blades, spindly stems with pale leaves, stunting of the plant, and deformed flowers, which sometimes show green colouring. Vegetable crops affected include carrot, celery, lettuce, potato, cucumber, pumpkin and squash.

References

External links

''Macrosteles quadrilineatus''
at bugguide.net {{Taxonbar, from=Q2972254 Macrostelini Insect vectors of plant pathogens Insects described in 1885