Brown marmorated stink bug

Brown marmorated stink bug
Adult
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hemiptera
Suborder:	Heteroptera
Family:	Pentatomidae
Genus:	Halyomorpha
Species:	H. halys
Binomial name
Halyomorpha halys Stål, 1855[1]

The brown marmorated stink bug (Halyomorpha halys) is an insect in the family

Like all stink bugs, the glands that produce the defensive chemicals (the smell) are located on the underside of the thorax, between the first and second pair of legs.[9]

Behavior

The odor from the stink bug is due to trans-2-decenal and trans-2-octenal.^[10] The smell has been characterized as a "pungent odor that smells like coriander."^[5] The stink bug's ability to emit an odor through holes in its abdomen is a defense mechanism evolved to prevent it from being eaten by birds and lizards. However, simply handling the bug, injuring it, or attempting to move it can trigger it to release the odor.

Reports on human cases are rare, but the stink bug's body fluids are toxic and irritating to the human skin and eyes. One case of keratitis has been reported in Taiwan.^[11]

Mating

During courtship, the male emits pheromones and vibrational signals to communicate with a female, which replies with her own vibrational signals, as in all stink bugs. The insects use the signals to recognize and locate each other. Vibrational signals of this species are noted for their low frequency, and one male signal type is much longer than any other previously described signals in stink bugs, although the significance of this is not yet clear.^[12]

Diet

The brown marmorated stink bug was accidentally introduced into the United States from China or Japan. It is believed to have hitched a ride as a stowaway in

Other reports have the brown marmorated stink bug documented as early as 2000 in New Jersey from a blacklight trap run by the Rutgers Cooperative Extension Vegetable Integrated Pest Management program in Milford, New Jersey.^[17]

In 2002, in New Jersey, it was found on plant material in Stewartsville, and was collected from blacklight traps in Phillipsburg and Little York. It was quickly documented and established in many counties in Pennsylvania, New Jersey, Delaware, Connecticut, and New York on the eastern coast of the United States.

By 2009, this agricultural pest had reached Maryland, West Virginia, Virginia, Tennessee, North Carolina, Kentucky, Ohio, Illinois, and Oregon.^[18] In 2010 it was found in Indiana,^[19] Michigan,^[20] Minnesota,^[21] and other states.^[22]

As of November 2011, it had spread to 34 U.S. states^[5] and by 2012 to 40, and showed an increase of 60% in total numbers over 2011.^[23]

Their populations have also spread to southern Ontario and Quebec, Canada.^[24][25] They have recently been found in southern British Columbia ^[26] and Southern Alberta.

Population increase

As of 2010, 17 states had been categorized as having established populations, and several other states along the eastern half of the United States were reported as having more than normal numbers of stink bugs.^[27][28] Stink bug populations rise because the climate in the United States is ideal for their reproduction. In optimal conditions, an adult stink bug can develop within 35 to 45 days after hatching.^[16] Female stink bugs are capable of laying 400 eggs in their lifetimes.^[29] The bug is also capable of producing at least one successful generation per year in all areas of the United States, no matter the climate. In warmer climates, multiple generations can occur annually, which can range from two generations in states such as Virginia to six generations in California, Arizona, Florida, Louisiana, Georgia, and Texas.^[16][30][31]

The addition of two more generations allowed the population to explode, leading to the establishment of several other populations in neighboring states. Currently, no environmental limiting factors are apparently slowing their distribution across North America. They also are extremely mobile insects, capable of moving from host to host without causing disruption in their reproductive processes. Currently, populations are estimated to continue to grow and spread to other states and provinces, especially during unusual periods of warm weather.^{[citation needed]}

Agricultural effects

The brown marmorated stink bug is a serious agricultural pest that has been readily causing damage to crops across the Eastern United States. They feed on a wide array of plants including apples, apricots, Asian pears, cherries, corn, grapes, lima beans, peaches, peppers, tomatoes, and soybeans.^[32] This makes them extremely versatile, as they do not require a specific plant on which to feed. To obtain their food, stink bugs use their stylets to pierce the plant tissue to extract the plant fluids.^[33] In doing so, the plant loses necessary fluids, which can lead to deformation of seeds, destruction of seeds, destruction of fruiting structures, delayed plant maturation, and increased vulnerability to harmful pathogens.^[33] While harvesting the plant's juices, the stink bug injects saliva into the plant, creating a dimpling of the fruit's surface and rotting of the material underneath.

The most common signs of stink bug damage are pitting and scarring of the fruit, leaf destruction, and a mealy texture to the harvested fruits and vegetables. In most cases, the signs of stink bug damage makes the plant unsuitable for sale in the market, as the insides are usually rotten. In field crops such as corn and soybeans, the damage may not be as evident as the damage seen in fruit plants. When stink bugs feed on corn, they go through the husk before eating the kernels, hiding the damage until the husks are removed during harvesting. The same damage is seen in soybeans, as the stink bug goes through the seed pods to acquire the juices of the seeds. One visual cue of stink-bug damage to soybean crops is the "stay green" effect, where damaged soybean plants stay green late into season, while other plants in the field die off normally. One can usually tell that a field of crops is infected because stink bugs are known for the "edge effect", in which they tend to infest crops 30–40 ft from the edge of the field.

Control

Control of stink bugs is a priority of the

Another recently introduced species from Asia, the large but non-threatening spider; Trichonephila clavata, also known as the Joro spider is a known predator of the stink bug while not posing a threat to native species. There is hope that it may be capable of reducing or controlling stink bug populations in North America as it continues to spread.^{[citation needed]}

Similarity in appearance to native species

Easily confused with