Halyomorpha halys (Stål) 265
expensive agricultural land. In addition, most orchards in Asia are located in or near forested or moun-
tainous areas, providing additional niches for this bug to utilize trees and shrubs as temporal or supple-
mental food sources. Because it has a wide host range and survives in various habitats, such diversified
orchard environments in Asia can provide suboptimal conditions for H. halys to survive and reproduce
throughout the growing season.
Beginning in the 2000s, development of organic orchards has become popular in China, Korea, and
Japan. Consequently, Halyomorpha halys has become one of the key problems (Zhang et al. 2007)
because of the lack of alternative control measures other than insecticides in organic farming systems.
Approximately 25–30% of apples damaged by this bug often has been reported (Zhang et al. 2007) and,
sometimes, more than 99% of pears injured in pear orchards has been observed (Fengjie et al. 1997).
Stink bugs including Halyomorpha halys are the most destructive pests of persimmon in Korea and
Japan where sweet persimmon, Diospryus kaki (Ericales: Ebenaceae), is widely cultivated (D. Lee
et al. 2001, K. Lee et al. 2002). In Japan, this bug is one of the major species damaging persimmon
(Kawada and Kitamura 1983a, Adachi 1998). Feeding by H. halys causes blemished and corky fruits,
decreasing the quality of persimmon. Also, fruit drop rate and feeding are higher with H. halys infes-
tations (Lee et al. 2009).
Citrus, Citrus unshiu Marcow (Rosids: Rutaceae), is produced mainly in southern China, Korea,
and Japan. Halyomorpha halys is the main pest damaging citrus fruits, producing blemish spots from
September to October (Kim et al. 2000). Specifically, extensive economic losses of yuzu, Citrus junos
Siebold ex Tanaka (Sapindales: Rutaceae), have been reported in Korea (Choi et al. 2000). Although
other stink bugs such as Glaucias subpunctatus (Walker) and Physopelta gutta (Burmeister) are active
at night, H. halys is diurnal as well as nocturnal in yuzu orchards.
4.5.1.1.2 Field Crops and Vegetables
Halyomorpha halys causes serious economic damage to soybean and grains in Asia (Kang et al. 2003).
It reduces yield and quality of soybean by feeding on pods and the milky contents of the bean (Son et
al. 2000, Kang et al. 2003, Bae et al. 2007, Paik et al. 2007). Although the first occurrence of H. halys
in soybean fields generally is observed in late July, it does not cause significant feeding damage to soy-
beans that are in the full-flowering stage of soybean (i.e. R2 stage). Rahman and Lim (2017) showed
that when a diet consisting of just pods or seeds only was provided to developing nymphs, feeding on
just the pods negatively impacted development time and mortality but not fecundity or egg viability and
that adults preferred to feed on seeds. However, the bug populations increase continuously as the plants
develop from full seed (R6) to full maturity (R8) stages, and their feeding causes significant economic
losses. H. halys is known to prefer indeterminate to determinate varieties of soybean and to prefer pod
to seed (Son et al. 2000, Bae et al. 2007, Paik et al. 2007).
Corn damage by Halyomorpha halys has been reported throughout Asian countries (Fukuoka et al.
2002, Yu and Zhang 2007), but the extent of the damage is not well documented. Pearl millet (Setaria
italica L.), sorghum (Sorghum bicolor L.), and common millet (Panicum miliaceum L.) are minor grains
in Asia. H. halys mainly occurs in sorghum or millet fields from August to October. It prefers sorghum
among the grains, and a large number of these bugs can be a serious problem in organic seed production
(Kim et al. 2010).
In Asia, relatively few economic losses by Halyomorpha halys on vegetables have been reported.
Major vegetables attacked include asparagus (Fukuoka et al. 2002), cucumber (Kawada and Kitamura
1983a, Fukuoka et al. 2002), pea, eggplant (Fukuoka et al. 2002), tomato (Oda et al. 1980), and vetch
(Bae et al. 2009).
4.5.1.1.3 Specialty Crops: Tea, Paulownia, Orchid, and Matrimony Vine
Stink bugs are emerging as pests in tea production in Asia by decreasing tea quality through sucking on
young leaves. They damage tea by decreasing the content of polyphenol (Murthy and Chandrasekaran
1979), water, total nitrogen, caffeine, and amino acid (Song et al. 2008). Specifically, in Korea, stink bugs
such as Plautia stali Scott and Halyomorpha halys are the major pests of tea. Tea leaves damaged by
these two species also show a decrease in the amount of catechin, a type of natural phenol causing strin-
gent taste in tea; significant reduction of epigallocatechin gallate also was found by Song et al. (2008).