Brown marmorated stink bug

Adult brown marmorated stink bugs are approximately long and about as wide, forming the heraldic shield shape characteristic of bugs in the superfamily Pentatomoidea. They are generally dark brown when viewed from above, with a creamy white-brown underside. Individual coloration may vary, with some bugs being various shades of red, grey, light brown, copper, or black. The term "marmorated" means variegated or veined, like marble, which refers to the markings of this species, including alternating light-colored bands on the antennae and alternating dark bands on the thin outer edge of the abdomen. The legs are brown with faint white mottling or banding. ==Behavior==

fruit The stink bug can emit an odor through holes in its thorax as a defense mechanism against being eaten by predators. However, simply handling the bug, injuring it, or attempting to move it can trigger it to release the odor. The odor is due to trans-2-decenal and trans-2-octenal. The smell has been characterized as a "pungent odor that smells like cilantro". Reports on human cases are rare; the stink bug's body fluids are toxic and irritating to human skin and eyes. One case of keratitis has been reported in Taiwan. Mating During courtship, the male emits pheromones and vibrational signals to communicate with a female, who 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. Diet The brown marmorated stink bug is a sap-sucking insect (like all Hemiptera or "true bugs") that uses its proboscis to pierce the host plant to feed. This feeding results, in part, in the formation of dimpled or necrotic areas on the outer surface of fruits, leaf stippling, seed loss, and possible transmission of plant pathogens. It is an agricultural pest that can cause widespread damage to fruit and vegetable crops. In Japan, it is a pest to soybean and fruit crops. In the U.S., the brown marmorated stink bug feeds, beginning in late May or early June, on a wide range of fruits, vegetables, and other host plants, including peaches, apples, green beans, soybeans, cherries, raspberries, and pears. ==In North America==

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 packing crates or on various types of machinery. The first documented specimen was collected in Allentown, Pennsylvania, in September 1998. Several Muhlenberg College students were reported to have seen these bugs as early as August of that same year. 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. In 2010 it was found in Indiana, Michigan, Minnesota, and other states. As of November 2011, it had spread to 34 U.S. states in 2020 Their populations have also spread to southern Ontario and Quebec, Canada. They have recently been found in southern British Columbia 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. 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. Female stink bugs can lay 400 eggs in their lifetimes. The bug can also produce 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. 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 are also 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. 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 an array of plants, including apples, apricots, Asian pears, cherries, corn, grapes, lima beans, peaches, peppers, tomatoes, and soybeans. 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. 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. Because the bugs insert their probosces below the surface of fruit and then feed, some insecticides are ineffective; in addition, the bugs are mobile, and a new population may fly in after the resident population has been killed, making permanent removal nearly impossible. With soybean infestations, spraying only the perimeter of a field may be the most effective method of preventing stink bugs from damaging the crops. However, even this method is limited, as new populations move back into the area, or the existing population simply moves to unaffected areas. Evidence also shows that stink bugs are developing resistance to pyrethroid insecticides, a common chemical used to combat infestations. The adult rice stink bug (Oebalus pugnax) is distinguishable from the brown marmorated stink bug by noting the straw color, the smaller size, and the elongated shape of the rice stink bug. ==In Europe==

The brown marmorated stink bug was likely first introduced to Europe during the repair work of the Chinese Garden in Zürich, Switzerland, in the winter of 1998. The stink bug has been traced back to have traveled with roof tiles that were imported from Beijing, China. The bug has since spread rapidly through Europe. The first sighting in southern Germany was made in Konstanz in 2011. In Italy the first specimens were found in Modena in 2012 and afterwards in South Tirol in 2016. The bug has also been sighted in Vienna, Austria, with increasing reports after 2016. The Italian region of Friuli-Venezia Giulia announced from 2017 to distribute 3.5 million euros to offset the costs of the lost crops of the fruit farmers until 2020. H. halys was first found in Portugal in Pombal in late 2018 or early 2019 Only in 2020 was H. halys confirmed to be reproducing and overwintering in the country. The stink bug has since spread to Georgia, where it continues to cause major damage to the local crops. From 2016 to 2018, the bug was estimated to have destroyed one-third of Georgia's hazelnut harvest, with yearly damages of up to €60 million Spread to Turkey The stink bug was first reported in Levent district of Istanbul in Turkey in September 2017. In October of the same year, it was observed in Artvin Province and the species has rapidly spread to other areas in Eastern Black Sea Region. In 2018, it was reported in Sakarya's Hendek district, and ; it is present in 8 provinces and 46 districts all across Turkey, with Artvin, Rize, Trabzon, Giresun, Samsun, and Yalova provinces being the most effected. The bug is believed to have entered the country through Georgia, as it was initially reported in Kemalpaşa, Artvin, just a few kilometers away from the border between both countries. Celal Tuncer, a professor from Ondokuz Mayıs University, has stated that the bug has already caused a 20% drop in Artvin's hazelnut yield and is expected to cause a 50% drop in hazelnut production and quality in the future. According to Tuncer, these drops would lead to US$1 billion in damages to hazelnut producers. ==Predators==

In China, Trissolcus japonicus, In the United States, Europe, and New Zealand, Trissolcus japonicus is a focus of biological control programs against the brown marmorated stink bug. This wasp was under study in the United States since 2007 for biosafety of possible introduction. Subsequent genetic testing showed these wild populations were self-introduced: they were not related to each other, or to a laboratory strain being studied in quarantine. Since then, several agricultural authorities have begun programs to augment wild populations with releases of laboratory-reared wasps. An adventive European population was discovered during similar surveys in Switzerland in 2017. Several parasitoids and predators indigenous to North America and Europe have been reported to attack stink bug eggs, nymphs, and adults. Researchers have also experimented with other predators like the spotted lady beetle, the spined soldier bug, and the common green lacewing, whereby the latter consumed most of the eggs of these tested species. Other research investigated different spider species, as well as the wheel bug Arilus cristatus. Several spider species attacked both the eggs and adult stink bugs. The Joro spider, another invasive Asian species, was identified in Georgia in 2015 and is a natural predator of the stink bug. Pill bugs eat stink bug eggs. Arilus cristatus, however, was the most voracious predator and attacked the eggs and adults more consistently.{{cite web|url=http://www.stopbmsb.org/stopBMSB/assets/File/Research/BMSB-SAP-Dec-2013/Native-Natural-Enemies-Shrewsbury.pdf|title=2.2.6 Native Natural Enemies of BMSB ==Life cycle==

File:Brown marmorated stink bug eggs on leaf.jpg|Eggs on leaf File:Halyomorpha halys05.jpg|Newly hatched eggs File:Brown marmorated stink bug eggs hatched.jpg|Newly hatched eggs File:Brown Marmorated Stink Bug nymph - Halyomorpha halys, Meadowood Farm SRMA, Mason Neck, Virginia.jpg|Nymph File:Pentatomidae - Halyomorpha halys (5th instar nymph).JPG|Third or fourth instar nymph File: Pentatomidae - Halyomorpha halys (6th last instar nymph).JPG|Fifth-instar nymph File:Halyomorpha halys and Plautia stali.JPG|Adult File:Brown marmorated stink bug adult.jpg|Adult File:Brown marmorated stink bug laying eggs.jpg|Laying eggs ==In houses and structures==

The brown marmorated stink bug is more likely to invade homes in the fall than others in the family. They enter under siding, into soffits, around window and door frames, chimneys, or any space which has openings big enough to fit through. Once inside the house, they go into a state of hibernation. They wait for winter to pass, but often the warmth inside the house causes them to become active, and they may fly clumsily around light fixtures. Two important vectors of this pest are the landscape ornamentals tree of heaven and princess tree. ==See also==