Halyomorpha halys (Stål)
The Brown Marmorated Stink Bug (Pentatomidae: Halyomorpha halys) is an introduced stink bug species from Asia that is spreading throughout the Mid-Atlantic United States, having been first collected in Pennsylvania in the fall of 1996 (Hoebeke and Carter 2003), with isolated populations occurring in Massachusetts, Mississippi, Ohio, Oregon, and California. It is native to South Korea, Japan, and eastern China, where it is a pest of tree fruit and soybeans. It has inflicted significant damage on fruit farms in the United States as well. (Hamilton 2009; Nielsen and Hamilton 2009) In 2007, this stink bug was reported for the first time from Europe (from several sites in the region around Zurich, Switzerland), suggesting that it may be spreading in Europe as well (Wermelinger et al. 2008)
The Brown Marmorated Stink Bug is univoltine in New Jersey and Pennsylvania (U.S.A.), with peak abundance from late July through early September, but if it becomes established in warmer parts of the United States it could have multiple generations per year, as it does in warmer parts of its native range. Minimum temperature thresholds for development of Brown Marmorated Stink Bugs studied in the United States are higher than reported from Japan, suggesting that U.S. populations may have originated in warmer parts of the native range, such as subtropical regions of China or India. (Nielsen et al. 2008; Nielsen and Hamilton 2009)
Overwintered adults emerge from hibernation sites in early spring. Mating and oviposition start about 2 weeks later. Sexually mature females usually mate more than once (as many as five times per day). A female mated only once can store enough sperm to lay eggs for nearly half her lifespan, but fecundity decreases in proportion to her age. The period of laying fertile eggs and fecundity increase with multiple copulations. Females deposit eggs on the lower leaf surfaces of host plants from May to late August. Egg clusters commonly contain 20 to 30 eggs, which hatch in 4 to 5 days. As with other pentatomids, H. halys has five nymphal instars. Emerging adults of the first generation are generally observed in early to mid-August. Development time from egg to adult is one to two months, depending on season and geography. (Hoebeke and Carter 2003 and references therein)
For a technical description of Halyomorpha halys (including the egg and each instar) and for details on distinguishing the genus Halyomorpha from other Old World genera, see Hoebeke and Carter (2003). Several dozen Halyomorpha species are known from Africa, Asia, and India (Hoebeke and Carter 2003).
In eastern North America, the only pentatomids that resemble Halyomorpha halys in overall size (12 to 17 mm) and dorsal coloration are species of the genus Brochymena. Brochymena species, however, have the juga each with a tooth on the outer side subapically and the pronotum with the anterolateral margins coarsely dentate. By comparison, H. halys lacks teeth on the outer juga subapically and the anterolateral margins of the pronotum are not dentate, but entire. (Hoebeke and Carter 2003)
In Europe, Halyomorpha halys might be confused with Holcostethus and Rhaphigaster nebulosa. In contrast to the 12 to 17 mm long Halyomorpha halys, Holcostethus are 9 to 10 mm in length and the front edges of the pronotum and the apex of the scutellum are pale. The head of R. nebulosa is quite regularly cone-shaped while that of H. halys shows a marked angle with a broadly rounded front. (Wermelinger et al. 2008)
The Brown Marmorated Stink Bug (Halyomorpha halys) is native to South Korea, Japan, and eastern China, but has been accidentally introduced to North America, where it is spreading throughout the Mid-Atlantic United States (Pennsylvania, New Jersey, Maryland, Virginia), with isolated populations occurring in Massachusetts, Mississippi, Ohio, Oregon, and California. It has also been reported recently from Switzerland, at several sites in the region around Zurich, suggesting that it may be spreading in Europe as well (Wermelinger et al. 2008).
Yang et al. (2009) described a new species of scelionid wasp, Trissolcus halyomorphae, that parasitizes the eggs of the Brown Marmorated Stink Bug in China, with observed parasitism rates of up to 70% or higher and an average annual rate of 50%. Because of the high parasitism rates and other biological features, this wasp appears to have good potential as a biocontrol agent. It appears to be the primary biological regulator of populations of Brown Marmorated Stink Bug in northern China (Yang et al. 2009) Native North American Trissolcus species apparently parasitize this stink bug in its introduced range in North America, but at a low rate (Nielsen and Hamilton 2009).
Evolution and Systematics
Systematics and Taxonomy
In the literature, the Brown Marmorated Stink Bug (Halyomorpha halys) in China is often misidentified as H. picta (Yang et al. 2009).
The Brown Marmorated Stink Bug is a highly polyphagous horticultural and agricultural pest (Hoebeke and Carter 2003 and references therein). It is a pest of tree fruits in Japan and South Korea, particularly persimmons, apples, and pears. It is the dominant stink bug pest on South Korean non-astringent persimmons(Diospyros kaki) and Yuzu (Citrus junos). (Nielsen and Hamilton 2009; Yang et al. 2009 and references therein) In China, it has become a serious pest of soybeans, vegetables, and tobacco, as well as many forest and ornamental trees, being especially harmful to orchards. It attacks a wide variety of fruits, including pear, apple, peach, plum, cherry, pomegranate, common jujube, citrus, persimmon, mulberry, hawthorn, apricot, grape, kiwifruit, and strawberry. Adult Brown Marmorated Stink Bugs generally feed on the fruit, whereas nymphs feed on leaves, stems, and fruit. This stink bug is also reported to be a vector of Paulownia witches' broom disease, an extremely destructive phytoplasma disease of Paulownia trees in China. (Yang et al. 2009 and references therein)