Halyomorpha halys (brown marmorated stink bug)

Adults and nymphs cause feeding damage. On tree fruits, feeding injury causes depressed or sunken areas that may become 'cat-faced' as the fruit develops. Late season injury causes corky spots on the fruit. Feeding may also cause fruiting structures to abort prematurely. Similar damage occurs in fruiting vegetables such as tomatoes and peppers, although frequently later in the season. Feeding can cause failure of seeds to develop in crops such as maize or soyabean. There is frequently a distinct edge effect in crop plots as H. halys has an aggregated dispersion and moves between crops or woodlots. In soyabeans, this can result in a 'stay green' effect where pods fail to senesce at the edges due to H. halys feeding injury.

In 2008-2009, increasing H. halys populations in the mid-Atlantic region of the USA caused late-season problems to tree fruit (Leskey and Hamilton, 2010a) though H. halys was not a widely recognized pest until late in the 2010 season. To date, H. halys has been recorded in many important USA agricultural production regions. H. halys distribution has continued to spread in the USA and has recently been recorded in orchard crop production regions in Oregon (Wiman et al., 2013) and could spread to other major production regions of similar crops throughout much of North America (Zhu et al., 2012). Susceptible crops in the USA where the bug is present are worth > $40 billion (NASS, 2013).

Nuisance impacts are especially problematic in rural areas, and have been reported in many urban and metropolitan regions. In the autumn, H. halys moves to structures, often by the thousands, generating numerous complaints (Inkley, 2012). Similar to the impacts on commercial growers, homeowners are also experiencing damage to backyard fruit and vegetable gardens.

H. halys attacks tree fruit (Nielsen and Hamilton, 2009a; Leskey et al., 2012a), small fruit, vegetables (Kuhar et al., 2012a), tree nuts (Hedstrom et al., 2013), ornamentals (Martinson et al., 2013) and row crops (Nielsen et al., 2011; Owens et al., 2013). In tree fruit, economic damage due to H. halys has resulted in increased production inputs and secondary pest outbreaks (Leskey et al., 2012a). In some cases, up to four-fold more pesticides were applied in affected fruit orchards (Leskey et al., 2012a). An outbreak in 2010 in the mid-Atlantic region resulted in > $37 million losses to apple alone and some stone fruit growers lost 90% of their crop (Leskey and Hamilton, 2010 a, b). Even unnoticeable populations in tree fruit may cause significant crop losses of up to 25% (Nielsen and Hamilton, 2009a). Tuncer and Ecevit (1997) and Tuncer et al. (2005) found that indigenous stink bugs in Turkey cause up to 3% direct crop loss to hazelnut. Should a similar scenario unfold in nut production areas in the USA, this may result in $200 million losses to tree nuts annually. Vegetables most at risk are sweetcorn, peppers, tomato, okra, aubergine, asparagus, cucurbits, crucifers and edible beans. Damage exceeding 50% is common under heavy infestations. With the exception of early sweetcorn, which may be damaged in early July, most vegetable crops are attacked from late July to September (Kuhar et al., 2012a). Taint and contamination of harvested fruit may also be an issue, particularly for small fruit and grapes. In wine made from H. halys-contaminated grapes, trans-2-decenal was the main taint compound (Mohekar et al., 2013) associated with H. halys. In some cases taint from stink bugs is transient and does not survive the fermentation/bottling process (Fiola 2012). Nevertheless, wines containing certain levels of this compound were perceived to be inferior compared to uncontaminated wines (Tomasino et al., 2013a, b). H. halys has been successfully removed from clusters just before harvest in order to prevent 'stink bug taint' (Pfeiffer et al., 2012).

To date only a single incidence of economic damage on pepper crops has been reported in Europe from the Canton Aargau in Switzerland (Sauer, 2012).