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from Balzac, Alberta (Bercha 2008, Fogain and Graff 2011). Additional reports include interceptions
in British Columbia in 2010 from lumber shipped from Virginia and Montreal, Quebec, in 2010 near
a skid that came from the United States. The first domestic report from a residence was in Hamilton,
Ontario, in 2010. Since then, this bug has become established in southern Ontario with multiple findings
in Hamilton, Mississauga (two building material shipments from the United States), Burlington, Toronto,
Milton, and Newboro in 2012; and Windsor, Cedar Springs, Vaughn, Niagara on the Lake and London
in 2013 (Gariepy et al. 2014a).
The occurrence of Halyomorpha halys in North America also can be examined based on the impact it
has in a geographic area (Anonymous 2015b). This shows that populations of this bug in the mid-Atlantic
United States (i.e., Delaware, New Jersey, Pennsylvania, Virginia, and West Virginia) have caused severe
agricultural problems and nuisance issues for the general public. Eight states (i.e., Connecticut, Indiana,
Kentucky, New York, Ohio, Oregon, Tennessee, and Washington) report agricultural and nuisance
issues. Ten states (i.e., Alabama, California, Georgia, Illinois, Michigan, Missouri, South Carolina,
Massachusetts, New Hampshire, and Vermont) and the province of Ontario in Canada report nuisance
issues only, whereas 16 states (i.e., Arkansas, Arizona, Colorado, Florida, Hawaii, Iowa, Indiana, Kansas,
Maine, Minnesota, Mississippi, Nebraska, New Mexico, Texas, Wisconsin, and Utah) and Quebec report
that this bug has been detected but has not become established.
The origins of Halyomorpha halys in North America have been investigated using DNA analysis. Xu
et al. (2014) traced the origins of the United States populations using three mitochondrial DNA genes
(COII, 12S Ribosomal DNA and 12S/CR) from specimens collected in 2004 and 2008 from China,
South Korea, Japan, and the United States. These analyses suggest that as a single H. halys introduction
from the Beijing area of China may be responsible for the initial dispersing United States population.
Using the same genes, additional haplotype diversity was found in more recent collections of speci-
mens from the west coast of the United States, which suggests that multiple introductions from different
parts of H. halys’s range in Asia have occurred (M-C. Bon, unpublished data). Gariepy et al. (2014b)
also examined the genetic diversity between Asia, Canada, Switzerland, and the United States using
the Cytochrome Oxidase I, 28S and Cytochrome b genes from field-collected specimens from these
countries and others intercepted prior to establishment in Canada. They concluded that the Canadian
populations originated from the movement of established United States populations, and that the North
American populations were the result of introductions from the Beijing/Hebei regions in China.
4.3.4 Other Areas
Due to Halyomorpha halys’ proven propensity to overwinter in shipping materials, etc., areas outside the
currently known distribution (Asia, Europe, and North America) are stepping up their efforts to prevent
the introduction of this bug (Leskey and Hamilton 2015). Two countries that especially are concerned
because of their unique ecological and agricultural systems are Australia and New Zealand (Duthie
2012, Leskey and Hamilton 2015, Lo et al. 2015). Currently, because of the potential threat and increase
in interceptions, these two countries now require that inspections of shipping cargo be conducted at the
port of origin to prevent these bugs from entering their countries (Leskey and Hamilton 2015).
The first report of Halyomorpha halys in South America comes from Chile where it was intercepted
by government officals in Iquique in 2011 but was not considered to be established. Today it has become
established in three areas in the Santiago metropolitan area (Faúndez and Rider 2017).
4.4 Biology
4.4.1 Life History
Halyomorpha halys is a multivoltine species with as many as five generations reported in southern China
(Hoffman 1931). In the mid-Atlantic United States, an area that experiences high population densities,
it is primarily bivoltine (Nielsen et al. 2008a). Adults overwinter in artificial and natural shelters and
gradually emerge from these sites beginning in April. There are few host plant resources available at