Journal of Pest Science (2018) 91:661–670
Halyomorpha halys, a serious threat for hazelnut in newly invaded
· Silvia T. Moraglio
· Luciana Tavella
Received: 4 July 2017 / Revised: 27 October 2017 / Accepted: 7 November 2017 / Published online: 16 November 2017
© Springer-Verlag GmbH Germany, part of Springer Nature 2017
Following its ﬁrst detection, Halyomorpha halys has become a key pest in many crops in NW Italy. In this area, one of the
most important crops is hazelnut, in which the species can cause severe damage through feeding on nuts. Therefore, semi-ﬁeld
trials were carried out in NW Italy to compare the harmfulness of H. halys with that of the local hazelnut bug species, such
as Gonocerus acuteangulatus, Nezara viridula, and Palomena prasina. Additionally, a 2-year ﬁeld survey was conducted in
hazel groves in NW Italy and W Georgia, another important hazelnut cropping area, to assess the presence and abundance
of the new invasive species and to evaluate the damage at harvest. Monitoring was carried out by plant beating and by com-
mercial traps throughout the growing season. In semi-ﬁeld trials, H. halys was the most harmful species, causing the highest
damage in kernels, and was able to survive and reproduce at higher rates. During ﬁeld surveys in NW Italy, H. halys was
sampled in groves late in the season in 2015 and, with higher populations, throughout the season in 2016. In W Georgia,
bug population levels consistently increased in the 2-year period, resulting in a signiﬁcant increase in damage at harvest in
2016. A similar trend is hence expected also in NW Italy in the following years. Moreover, data on individuals collected in
diﬀerent points of the hazelnut groves conﬁrmed the border-driven behavior of this pest, leading to consideration of potential
integrated pest management solutions.
Keywords Brown marmorated stink bug · Semi-ﬁeld trials · Field surveys · Damage evaluation · NW Italy · W Georgia
Halyomorpha halys has become a serious pest in NW
In semi-ﬁeld trials, H. halys was more harmful than com-
mon hazelnut pest bug species because of greater damage
on kernels and maximum survival and reproductive rates.
In ﬁeld surveys, in NW Italy H. halys was scarcely found
in 2015–2016, whereas in W Georgia its population
consistently increased in 2016, resulting in signiﬁcantly
A similar trend is hence expected on hazelnut in NW
Italy in the following years.
Diﬀerent bug species belonging to the families Coreidae and
Pentatomidae (Hemiptera: Heteroptera) are responsible for
economic damage to hazelnut in the main producing areas
of Europe and Turkey (Moraglio et al. 2014; Tuncer et al.
2014; Erper et al. 2016). Adults and nymphs can cause dif-
ferent types of damage in relation to the period when they
feed on the nuts: early attacks during nut development, i.e.,
in May–early June, lead to an increase in seed abortion and
early nut drop, while later attacks during kernel growth,
i.e., in mid-June–August, determine symptoms on kernels,
such as whitish or brownish spots, spongy tissue, and sur-
face depression (Boselli 1932; Tavella et al. 2001a, 2003).
Damage on kernels results from an injection of saliva rich
of enzymes during feeding, which changes kernel composi-
tion (Vaccino et al. 2008; Memoli et al. 2017). Currently,
Communicated by D.C. Weber.
* Luciana Tavella
Dipartimento di Scienze Agrarie, Forestali e Alimentari
(DISAFA), ULF Entomologia Generale e Applicata,
University of Torino, Largo P. Braccini 2, 10095 Grugliasco,