''Sitophilus'' is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
weevil
Weevils are beetles belonging to the Taxonomic rank, superfamily Curculionoidea, known for their elongated snouts. They are usually small, less than in length, and Herbivore, herbivorous. Approximately 97,000 species of weevils are known. They b ...
s in the
tribe
The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide usage of the term in English language, English is in the discipline of anthropology. This definition is contested, in p ...
Litosomini
The LitosominiLacordaire JT (1866) ''Histoire naturelle des insectes. Genera des coléoptères ou exposé méthodique et critique de tous les genres proposés jusqu’ici dans cet ordre d’insectes. Les familles des Curculionides (suite), Scolyt ...
. Some species are familiar as
pests
PESTS was an anonymous American activist group formed in 1986 to critique racism, tokenism, and exclusion in the art world. PESTS produced newsletters, posters, and other print material highlighting examples of discrimination in gallery represent ...
of stored grain, nut, or seed. Notable pest species include the
rice weevil
Rice is the seed of the grass species ''Oryza sativa'' (Asian rice) or less commonly ''Oryza glaberrima'' (African rice). The name wild rice is usually used for species of the genera ''Zizania'' and '' Porteresia'', both wild and domesticated, ...
(''S. oryzae''),
wheat weevil
The wheat weevil (''Sitophilus granarius''), also known as the grain weevil or granary weevil, is an insect that feeds on cereal grains, and is a common pest in many places. It can cause significant damage to harvested stored grains and may drasti ...
(''S. granarius''), and
maize weevil
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. The ...
(''S. zeamais'').
Among the ''Stiophilus'' are species which destroy stored
wheat
Wheat is a grass widely cultivated for its seed, a cereal grain that is a worldwide staple food. The many species of wheat together make up the genus ''Triticum'' ; the most widely grown is common wheat (''T. aestivum''). The archaeologi ...
,
rice
Rice is the seed of the grass species ''Oryza sativa'' (Asian rice) or less commonly ''Oryza glaberrima
''Oryza glaberrima'', commonly known as African rice, is one of the two domesticated rice species. It was first domesticated and grown i ...
,
sorghum
''Sorghum'' () is a genus of about 25 species of flowering plants in the grass family (Poaceae). Some of these species are grown as cereals for human consumption and some in pastures for animals. One species is grown for grain, while many othe ...
,
[Control of Sitophilus zeamais Mots., 1958 and Sitophilus oryzae (L., 1763) weevils (Coleoptera, Curculionidae) in stored rice grain (Oryza sativa l.) with insecticide pirimiphos methyl (Actellic 500 CE)]
B. Alleoni1, W. Ferreira 9th International Working Conference on Stored Product Protection oats
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 ...
,
barley
Barley (''Hordeum vulgare''), a member of the grass family, is a major cereal grain grown in temperate climates globally. It was one of the first cultivated grains, particularly in Eurasia as early as 10,000 years ago. Globally 70% of barley pr ...
,
rye,
buckwheat
Buckwheat (''Fagopyrum esculentum''), or common buckwheat, is a flowering plant in the knotweed family Polygonaceae cultivated for its grain-like seeds and as a cover crop. The name "buckwheat" is used for several other species, such as '' Fago ...
,
[ ]peas
The pea is most commonly the small spherical seed or the seed-pod of the flowering plant species ''Pisum sativum''. Each pod contains several peas, which can be green or yellow. Botanically, pea pods are fruit, since they contain seeds and d ...
, cottonseed
Cottonseed is the seed of the cotton plant.
Composition
The mature seeds are brown ovoids weighing about a tenth of a gram. By weight, they are 60% cotyledon, 32% coat and 8% embryonic root and shoot. These are 20% protein, 20% oil and 3.5% sta ...
, processed cereal
A cereal is any Poaceae, grass cultivated for the edible components of its grain (botanically, a type of fruit called a caryopsis), composed of the endosperm, Cereal germ, germ, and bran. Cereal Grain, grain crops are grown in greater quantit ...
products such as pasta
Pasta (, ; ) is a type of food typically made from an unleavened dough of wheat flour mixed with water or eggs, and formed into sheets or other shapes, then cooked by boiling or baking. Rice flour, or legumes such as beans or lentils, are som ...
, cassava
''Manihot esculenta'', common name, commonly called cassava (), manioc, or yuca (among numerous regional names), is a woody shrub of the spurge family, Euphorbiaceae, native to South America. Although a perennial plant, cassava is extensively ...
,[ and fruits such as ]apples
An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple fruit tree, trees are agriculture, cultivated worldwide and are the most widely grown species in the genus ''Malus''. The tree originated in Central Asia, wh ...
.
Distribution
The rice and maize weevils have a nearly cosmopolitan distribution
In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the world in appropriate habitats. Such a taxon, usually a species, is said to exhibit cosmopolitanism or cosmopolitism. The ext ...
, occurring throughout the warmer parts of the world. In Europe they are replaced by the temperate Palearctic
The Palearctic or Palaearctic is the largest of the eight biogeographic realms of the Earth. It stretches across all of Eurasia north of the foothills of the Himalayas, and North Africa.
The realm consists of several bioregions: the Euro-Sibe ...
wheat weevil
The wheat weevil (''Sitophilus granarius''), also known as the grain weevil or granary weevil, is an insect that feeds on cereal grains, and is a common pest in many places. It can cause significant damage to harvested stored grains and may drasti ...
.
Biology
The adult female weevil bores a hole in a grain, nut, or seed, and deposits an egg, usually one egg per individual grain. She seals the hole with a secretion. The larva
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
The ...
develops while feeding on the interior of the grain, and then pupa
A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their ...
tes. It usually leaves the grain completely hollow when it exits as an adult.[Plarre, R. (2010)]
An attempt to reconstruct the natural and cultural history of the granary weevil, ''Sitophilus granarius'' (Coleoptera: Curculionidae).
''Eur J Entomol'' 107, 1-11. The wheat weevil can live on acorn
The acorn, or oaknut, is the nut of the oaks and their close relatives (genera ''Quercus'' and '' Lithocarpus'', in the family Fagaceae). It usually contains one seed (occasionally
two seeds), enclosed in a tough, leathery shell, and borne ...
s, and may have used them as a host before agriculture made grain plentiful. The rice weevil can live on beans, nuts, grains, and some types of fruit, such as grape
A grape is a fruit, botanically a berry, of the deciduous woody vines of the flowering plant genus ''Vitis''. Grapes are a non- climacteric type of fruit, generally occurring in clusters.
The cultivation of grapes began perhaps 8,000 years ago, ...
s. Several other ''Sitophilus'' use the acorns of oak
An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...
s such as bluejack oak
''Quercus incana'' is a species of oak known by the common names bluejack oak, upland willow oak, sandjack oak, and cinnamon oak. It is native to the Atlantic coastal plain, Atlantic and Gulf coastal plains of the United States, from Virginia arou ...
(''Quercus incana'') and moru oak (''Q. floribunda''). Some use the seeds of trees in the Dipterocarpaceae
Dipterocarpaceae is a family of 16 genera and about 695 known species of mainly tropical lowland rainforest trees. The family name, from the type genus ''Dipterocarpus'', is derived from Greek (''di'' = two, ''pteron'' = wing and ''karpos'' = fru ...
and the legume
A legume () is a plant in the family Fabaceae (or Leguminosae), or the fruit or seed of such a plant. When used as a dry grain, the seed is also called a pulse. Legumes are grown agriculturally, primarily for human consumption, for livestock f ...
family, . The tamarind weevil (''S. linearis'') is only known from the seeds of tamarind
Tamarind (''Tamarindus indica'') is a Legume, leguminous tree bearing edible fruit that is probably indigenous to tropical Africa. The genus ''Tamarindus'' is monotypic taxon, monotypic, meaning that it contains only this species. It belongs ...
.[
Several ''Sitophilus'' species are hosts to an intracellular γ-Proteobacterium. Weevil and bacterium have a ]symbiotic
Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...
relationship in which the bacterium produces nutrients such as amino acids and vitamins for the host, supplementing its cereal diet.[Vallier, A., et al. (2009)]
RNAi in the cereal weevil ''Sitophilus'' spp: systemic gene knockdown in the bacteriome tissue.
''BMC Biotechnology'' 9(1), 44.
Diversity
As of 1993, there are about 14 species of ''Sitophilus''.[
Species include:][
*'' Sitophilus conicollis''
*'' Sitophilus cribrosus''
*'' Sitophilus erosa''
*'' Sitophilus glandium''
*'']Sitophilus granarius
The wheat weevil (''Sitophilus granarius''), also known as the grain weevil or granary weevil, is an insect that feeds on cereal grains, and is a common pest in many places. It can cause significant damage to harvested stored grains and may drasti ...
'' – wheat weevil, granary weevil
*'' Sitophilus linearis'' – tamarind weevil
*'' Sitophilus oryzae'' – rice weevil
*'' Sitophilus quadrinotatus''
*'' Sitophilus rugicollis''
*'' Sitophilus rugosus''
*'' Sitophilus sculpturatus''
*'' Sitophilus vateriae''
*''Sitophilus zeamais
''Sitophilus'' is a genus of weevils in the tribe Litosomini. Some species are familiar as pests of stored grain, nut, or seed. Notable pest species include the rice weevil (''S. oryzae''), wheat weevil (''S. granarius''), and maize weevil (''S. ...
'' – maize weevil
Fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
taxa include:
*'' Sitophilus punctatissimus''
References
External links
* Obata, H., et al. (2011)
A new light on the evolution and propagation of prehistoric grain pests: The world's oldest maize weevils found in Jomon Potteries, Japan.
'' PLoS ONE'' 6(3) e14785. .
{{Taxonbar, from=Q1431435
Dryophthorinae
Insect pests of millets
Storage pests