268 Invasive Stink Bugs and Related Species (Pentatomoidea)
to the Po Valley region of Moderna, Reggio Emilia, and Bologna where it caused damage to apples,
apricots, peaches, pears, persimmons, plums, and tomatoes (Bariselli et al. 2016). In Hungary, H. halys
has been found in and around Budapest (Vétek et al. 2014). The initial finding was inside a building at
the Buda Arboretum. Subsequent findings were made near an apple orchard in Péterimajor. In Greece,
this stink bug first was collected in Athens in the autumn of 2011 and, to date, has not been considered
an agricultural pest (Milonas and Parsinevelos 2014). Recently, H. halys has been found in Vorarlberg
and Vienna, Austria; Bucharest, Romania; and Sofia, Bulgaria (Macavei et al. 2015, Rabitsch and Friebe
2015, Simov 2016). For each Austrian detection, specimens were collected from buildings. In Romania,
initial collections were made from the Botanical Garden of Bucharest. Further collections were made in
urban areas in Bucharest, which were several kilometers away from the initial collection site. In 2016,
H. halys was found infesting corn, goji, and field and edible roses with 100% crop loss occurring in goji
(Roxana et al. 2016). Also in 2016, H. halys was reported from Girona, Spain, and Sardina, Italy (Dioli
et al. 2016). Given this bug’s ability to stow away in luggage, cars, and shipping containers, it is probable
that it will be found in additional countries in Europe (Haye et al. 2015b).
4.5.2.1 Phenology in Europe
The life-cycle of Halyomorpha halys has been investigated in Swiss populations by Haye et al. (2014b).
They reported that adults hibernate and appear around April with oviposition starting in early July and
lasting until the end of September. However, latecomers did not struggle to survive. Development from
egg to maturity required between 60 and 131 days. The new generation appeared from mid-August
onwards. One generation per year developed in Switzerland, but two generations per year are to be
expected in the Mediterranean area in southern Europe (Haye et al. 2014b).
4.5.2.2 Host Range in Europe
This polyphagous species has been recorded from 51 host plant species in 32 families with highest popu-
lations on the native Sorbus aucuparia, Cornus sanguinea, and Fraxinus excelsior; and the non-native
North American Catalpa bignonioides and Parthenocissus quinquefolia (Haye et al. 2014a). There is no
doubt that the list will increase with the continued spread of the species in Europe.
4.5.3 Halyomorpha halys in North America
4.5.3.1 Urban Nuisance Pest
Initially, upon its introduction into the United States, Halyomorpha halys was considered to be a nui-
sance pest because of its overwintering preference for man-made structures such as houses and com-
mercial buildings (Hoebeke and Carter 2003). This also has been the case in Canada where it currently
is considered only a nuisance pest (Gariepy et al. 2014a).
The overwintering behavior normally is the first contact humans have with Halyomorpha halys and
frequently results in the presence of large overwintering populations (Inkley 2012). In one documented
case, Inkley (2012) collected 26,205 adults during a 6-month period from January to June inside the
first, second and third floors of a house. This behavior and the large numbers that can come in contact
with humans within a structure has led to concern that H. halys could become a new aeroallergen (Merz
et al. 2012), adding to the list of insects such as cockroaches and ladybugs that cause rhinitis/conjunctivitus
responses upon contact (Kagen 1990, Yarbough et al. 1999, Ray and Pence 2004, Albright et al. 2006,
Sharma et al. 2006). Mertz et al. (2012) investigated this potential and demonstrated that out of 15
patients tested with known prior exposure to H. halys, 11 exhibited reactions to this bug in skin tests.
What attracts Halyomorpha halys to structures and where they prefer to settle have been ongoing
questions. To answer the question about attraction to buildings, The Great Stinkbug Count was con-
ducted in 2013 (Torri J. Hancock, unpublished data; see Acknowledgments; in Leskey and Hamilton
2015). This study used a citizen science survey to evaluate several structural characteristics including
color, compass orientation, and surrounding landscape and found that residences with brown exteriors