''Oebalus pugnax'', the rice stink bug, is a flying insect in the shield bug family

Pentatomidae Pentatomidae is a family of insects belonging to the order Hemiptera, generally called shield bugs or stink bugs. Pentatomidae is the largest family in the superfamily Pentatomoidea, and contains around 900 genera and over 4700 species.Robert G ...

native to North America that has become a major agricultural pest in the Southern United States. It has been a known pest since at least the time of

Johan Christian Fabricius Johann Christian Fabricius (7 January 1745 – 3 March 1808) was a Danish zoologist, specialising in "Insecta", which at that time included all arthropods: insects, arachnids, crustaceans and others. He was a student of Carl Linnaeus, and is co ...

, who described the species in 1775.

Description

The adult ''Oebalus pugnax'' measures to long. It has a narrow profile that forms the shield shape characteristic of other stink bugs. These

true bug 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 to a ...

s are typically straw-colored with sharp points on the apex of the shield and a yellow triangle exhibited on center of the shield. Some adults have gray coloring near the yellow triangle, while others may be a darker brown rather than straw-colored. However, the rice stink bug is easily distinguished from other stink bugs because of its narrower profile and lighter color than, for example, the

brown marmorated stink bug The brown marmorated stink bug (''Halyomorpha halys'') is an insect in the family Pentatomidae, native to China, Japan, Korea, and other Asian regions. In September 1998, it was collected in Allentown, Pennsylvania, where it is believed to have ...

Behavior and crop damage

The rice stink bug is a significant pest of

rice Rice is a cereal grain and in its Domestication, domesticated form is the staple food of over half of the world's population, particularly in Asia and Africa. Rice is the seed of the grass species ''Oryza sativa'' (Asian rice)—or, much l ...

crops in the southern U.S., including Mississippi, Arkansas, Louisiana, and Texas (the

Rice Belt The Rice Belt of the United States includes Arkansas, Louisiana, Mississippi, and Texas, four southern U.S. states that grow a significant portion of the nation's rice crop. The name is in conformity with the Corn Belt of the Midwestern United ...

). This agricultural pest is known to attack cereal crops with small seeds, particularly

wheat Wheat is a group of wild and crop domestication, domesticated Poaceae, grasses of the genus ''Triticum'' (). They are Agriculture, cultivated for their cereal grains, which are staple foods around the world. Well-known Taxonomy of wheat, whe ...

sorghum ''Sorghum bicolor'', commonly called sorghum () and also known as great millet, broomcorn, guinea corn, durra, imphee, jowar, or milo, is a species in the Poaceae, grass genus ''Sorghum (genus), Sorghum'' cultivated for its grain. The grain i ...

, and rice. The insect also lives in wild grasses such as

Johnson grass Johnson grass or Johnsongrass, ''Sorghum halepense'', is a plant in the grass family, Poaceae, native to Asia and northern Africa. The plant has been introduced to all continents except Antarctica, and most larger islands and archipelagos. It re ...

, barnyard grass, and

sedge The Cyperaceae () are a family of graminoid (grass-like), monocotyledonous flowering plants known as wikt:sedge, sedges. The family (biology), family is large; botanists have species description, described some 5,500 known species in about 90 ...

, making control of cash crops difficult. They are occasionally found on other crops in which grasses are prevalent between the rows, even though the insect may ignore the field crop. The insect is extremely mobile and is known to travel en masse in and out of fields quickly in search of more favorable foods. Non-food crop hosts of the rice stink bug include: ''

Echinochloa crusgalli ''Echinochloa crus-galli'' is a type of wild grass originating from tropical Asia that was formerly classified as a type of panicum grass. It is commonly known as cockspur (or cockspur grass), barnyard millet, Japanese millet, water grass, common ...

Echinochloa colona ''Echinochloa colona'', commonly known as jungle rice, wild rice, deccan grass, jharua or awnless barnyard grass, is a type of wild grass originating from tropical Asia. It was formerly classified as a species of ''Panicum''. It is the wild anc ...

Digitaria sanguinalis ''Digitaria sanguinalis'' is a species of Poaceae, grass known by several common names, including hairy crabgrass, hairy finger-grass, large crabgrass, crab finger grass, purple crabgrass. It is one of the better-known species of the genus ''Digi ...

, Panicum dicotomiflorum, Phalaris minor, Paspalum urvillei'', and '' Sporobolus poiretti''; the last two are the most common species that the bug prefers. The rice stink bug will damage a developing seed head by feeding on the seed's

endosperm The endosperm is a tissue produced inside the seeds of most of the flowering plants following double fertilization. It is triploid (meaning three chromosome sets per nucleus) in most species, which may be auxin-driven. It surrounds the Embryo#Pla ...

, leaving an empty shell or shriveled kernels. This type of damage can precipitate microorganism diseases and other crop losses, most notably discoloration, "pecky rice," and lower quality produce. When ''Oebalus pugnax'' are found in non-target crops such as standing

corn Maize (; ''Zea mays''), also known as corn in North American English, is a tall stout Poaceae, grass that produces cereal grain. It was domesticated by indigenous peoples of Mexico, indigenous peoples in southern Mexico about 9,000 years ago ...

, they can be ignored since they "generally do not feed in corn." However,

seedling A seedling is a young sporophyte developing out of a plant embryo from a seed. Seedling development starts with germination of the seed. A typical young seedling consists of three main parts: the radicle (embryonic root), the hypocotyl (embry ...

corn is susceptible to the rice stink bug. Although the rice stink bug is the source cause of "pecky rice" damage in rice crops, the kernel spotting and discoloration is the result of a

fungal infection Fungal infection, also known as mycosis, is a disease caused by fungi. Different types are traditionally divided according to the part of the body affected: superficial, subcutaneous, and systemic. Superficial fungal infections include common ...

of the rice kernels by fungi such as species of the ubiquitous genus ''

Fusarium ''Fusarium'' (; ) is a large genus of filamentous fungi, part of a group often referred to as hyphomycetes, widely distributed in soil and associated with plants. Most species are harmless saprobes, and are relatively abundant members of the s ...

''.

Related species

In South America, the small rice stink bug, '' Oebalus poecilus'' (also ''Solubea poecila''), is the most destructive pest of rice crops. It attacks rice, barley, oats, corn, and wheat, while it occasionally attacks soybean, cotton, and guava. The small rice stink bug looks similar to the rice stink bug.

References

{{Taxonbar, from=Q5413599 Pentatomini Agricultural pest insects Insects described in 1775 Taxa named by Johan Christian Fabricius Hemiptera of North America Insect pests of rice

Description

Behavior and crop damage

Related species

See also

References