Megacopta cribraria
Bean Plataspid
Synonym(s):
Class: Insecta
Order: Hemiptera
Family: Plataspidae
Photographer: Joseph Eger, Dow AgroSciences
Source: http://www.freshfromflorida.com/pi/pest_alerts/bean-plataspid-pest-alert.html
Description
Adult Description: The bean plataspid (Megacopta cribraria) also commonly known as the lablab bug and globular stink bug. This insect is 3-5 mm in length, has a round body shape, and a dorsally flattened posterior end. The body color is brown with darker punctures along the dorsal side of the abdominal region.
Larva Description: Nymphs look similar to the adult bean plataspid in shape, but have a lighter brown color and wing buds that develop through 5 instars.
Host Plant: Soy beans, kudzu, and other leguminous crops
Ecological Threat: Leguminous crops are at the highest risk as they are the preferred plant for the bean blataspid to feed on. The economic impact on these plants results from damage to petioles and pods causing wilting of the plant and reduced yield from a poor seed set. China reports reduced soybean yields up to 50 percent in spring months and up to 30 percent in summer months. bean plataspids have been recorded to aggregate in high numbers on houses as well as fields. An odor is released from the insect if disturbed making the pest more challenging to deal with when they accumulate on homes in the fall months.
Biology: The bean plataspid produces three generations per year when it must overwinter. However, in India it has been reported to survive throughout the year with no overwintering period. Mating has been reported to occur during the summer months in Georgia.
History: The bean plataspid was introduced to the United States fairly recently with the first reports in 2009. The exact method of transportation from Asia is unknown. However, they have been observed attached to clothing and vehicles, which serves as a mode of dispersal throughout the United States.
U.S. Habitat: The bean plataspid can be found in fields of leguminous crops during warm weather months, and it moves to find shelter in homes or barns when the weather becomes cooler in the fall and winter months.
Distribution
Native Origin: China
U.S. Present: The first reports of the bean plataspid were from Georgia in 2009. Recently, USA Today reported sightings in North Carolina, South Carolina, and Alabama.
Texas: No reported sightings
Resembles/Alternatives
Management
A known natural egg parasite Dirphys boswelli has been found as an effective control for the bean plataspid. This tiny wasp has been studied as a control agent of several insects that pose economical damage to crops.
The USDA and APHIS are currently working to test pesticides specific for the bean plataspid as well as explore other natural predators in addition to the wasp Dirphys boswelli.
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References
Polaszek, A. and M. Hayat. 1990. Dirphys boswelli (Hymenoptera: Aphelinidae) an egg-parasitoid of Plataspidae (Heteroptera). Journal of Natural History 24(1):1-5, 7 figs.
Internet Sources
http://bugguide.net
http://www.freshfromflorida.com
http://www.aphis.usda.gov/