''Sitobion avenae'', the English grain aphid, is an

aphid Aphids are small sap-sucking insects in the Taxonomic rank, family Aphididae. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white Eriosomatinae, woolly ...

in the superfamily Aphidoidea in the order

Hemiptera Hemiptera (; ) is an order of insects, commonly called true bugs, comprising more than 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, assassin bugs, bed bugs, and shield bugs. They range in size from ...

. It is a true bug and sucks sap from plants. It lives on grasses, sedge and rushes and can be a significant pest of cereals. This species act as a host of the entomophthoralean fungi.

Parthenogenesis

Some

genotype The genotype of an organism is its complete set of genetic material. Genotype can also be used to refer to the alleles or variants an individual carries in a particular gene or genetic location. The number of alleles an individual can have in a ...

s of ''S avenae'' are obligate parthenogens and some are cyclical parthenogens. Cyclically parthenogenetic lines can reproduce parthenogenetically in the spring and summer. Production of sexual females and males is induced during autumn by decreasing day length and decreasing temperature. Mating followed by egg laying occurs on grasses (

Poaceae Poaceae ( ), also called Gramineae ( ), is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos, the grasses of natural grassland and species cultivate ...

) during late November. Eggs can overwinter with delayed development (

diapause In animal dormancy, diapause is the delay in development in response to regular and recurring periods of adverse environmental conditions.Tauber, M.J., Tauber, C.A., Masaki, S. (1986) ''Seasonal Adaptations of Insects''. Oxford University Press It ...

), and then, after being exposed to cold for two or three months, can hatch spontaneously and initiate the next cycle of clonal reproduction.

References

* http://aphid.aphidnet.org/Sitobion_avenae.php * http://www7.inra.fr/hyppz/RAVAGEUR/6sitave.htm * http://www.agroatlas.ru/en/content/pests/Sitobion_avenae/ * http://entoweb.okstate.edu/ddd/insects/englishgrainaphid.htm Agricultural pest insects Macrosiphini Insect pests of millets Fauna of the United Kingdom {{Aphididae-stub