FAVNISTIČNI ZAPISKI / FAUNISTICAL NOTES
FIRST REPORT OF INVASIVE SPECIES LEPTOGLOSSUS
OCCIDENTALIS IN KOSOVO (HETEROPTERA: COREIDAE)
Dejan KULIJER1 and Halil IBRAHIMI2
1 National Museum of Bosnia and Herzegovina, Zmaja od Bosne 3, 71000 Sarajevo,
Bosnia and Herzegovina; dejan.kulijer@gmail.com
2 Department of Biology, Faculty of Mathematical and Natural Sciences, 
University of Prishtina “Hasan Prishtina”, 
Mother Teresa p.n. 10000 Prishtina, Kosovo; halil.ibrahimi@uni-pr.edu
Abstract – First records of the invasive western conifer seed bug (Leptoglossus oc-
cidentalis Heidemann, 1910) in Kosovo are presented and discussed. This finding
complements the known range of the species in the Balkan Peninsula with Albania
now being the only country without confirmation of its presence.
KEY WORDS: alien species, Balkan Peninsula, distribution, Hemiptera, insects, Pinaceae,
true bugs.
Izvleček – PRVO POROČANJE O INVAZIVNI VRSTI LEPTOGLOSSUS OCCI-
DENTALIS NA KOSOVU (HETEROPTERA: COREIDAE)
Predstavljeni so prvi podatki o pojavljanju tujerodne invazivne stenice storževe
listonožke (Leptoglossus occidentalis Heidemann, 1910) na Kosovu. To poročanje
dopolnjuje znano razširjenost vrste na Balkanskem polotoku, od koder je sedaj potrjena
prisotnost vrste v vseh državah z izjemo Albanije.
KLJUČNE BESEDE: tujerodne vrste, Balkanski polotok, razširjenost, Hemiptera, storževa
listonožka, Pinaceae, polkrilci.
Western conifer seed bug (Leptoglossus occidentalis Heidemann, 1910) is an in-
vasive species of Nearctic origin native to the area of North America west of Rocky
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Mts., from British Columbia to North Mexico (McPherson et al. 1990; Dusoulier et
al. 2007). First introduction to Europe was recorded in Italy, near Vicenza in 1999
(Taylor et al. 2001). L. occidentalis spread fast across the continent and within 15
years it was reported from all parts of Europe, including Portugal, England, Norway,
Turkey, Ukraine and Russia (Fent & Kment 2011; Gapon 2013). Although its expan-
sion in Italy and neighboring countries was probably the result of natural spreading
of established Italian population, some other isolated and mutually distant records
suggest independent introductions or secondary translocations within Europe (Du-
soulier et al. 2007; Rabitsch 2008). 
In North America the Western conifer seed bug is considered to be a serious pest
in seed orchards of conifers (e. g. McPherson et al. 1990). The species feeds on de-
veloping seeds and flowers of different conifer species, with a preference for Pinaceae,
causing reduction of seed fertility. Another negative impact of L. occidentalis is that
it can also become the nuisance to people. As the weather cools in autumn, adults
search suitable sheltered overwintering places for hibernation and often aggregate in
homes and other buildings, sometimes in large numbers (Fent & Kment 2011).
Although L. occidentalis already spread across the whole Balkan Peninsula (Fent
& Kment 2011) until now it was not reported from Kosovo. This paper presents first
documented and verified observations of the species for this country. Adult western
conifer seed bugs were collected at four sites in eastern (13/VII/2015) and western
(20/III/2016) Kosovo (Fig. 1). The sampling was carried out by handpicking and the
collected specimens were preserved in 80 % ethanol. L. occidentalis from Batllavë
Lake and Ballaban village are deposited at the Laboratory of Zoology of the Depart-
ment of Biology, Faculty of Mathematical and Natural Sciences, University of Pr-
ishtina, Kosovo. One specimen from the Patriarchate of Pejë/Peć is deposited in the
collections of the National Museum of Bosnia and Herzegovina in Sarajevo. Both lo-
calities in the east are situated in the area of Batllavë Lake, one of the largest lakes in
Kosovo, while the localities in western part of Kosovo, Pejë Monastery and Deçan
Monastery, are located at the foothills of Bjeshkët e Nemuna Mountains.
Acta entomologica slovenica, 25 (1), 2017
116
Fig. 1: Study area and the finding sites of
Leptoglossus occidentalis Heidemann in Kosovo.
Material examined: Loc. 1. Podujevë Municipality, Batllavë Lake, N
42.817626° E 21.310313°, 13/VII/2015, 653 m a.s.l., 2 adults, H. Ibrahimi leg. &
det.; Loc. 2. Podujevë Municipality, Ballaban village, N 42.795226° E 21.322476°,
13/VII/2015, 682 m a.s.l., 1 adult, H. Ibrahimi leg. & det.; Loc. 3. Pejë Municipality,
Garden of the Patriarchate of Peć/Pejë, N 42.661111° E 20.265556°, 20/III/2016,
543 m a.s.l., 1 adult, D. Kulijer leg. & det; Loc. 4. Deçan Municipality, Visoki
Dečani (Deçan) Monastery, N 42.547222° E 20.266944°, 20/III/2016, 660 m a.s.l.,
6 adults, D. Kulijer leg. & det (Fig. 2).
As Balkan Peninsula is largely undersampled for L. occidentalis in comparison to
other parts of Europe, it can be assumed that the species is much more common in the
area then can be seen from available data. The recent discovery of L. occidentalis in
Macedonia (Kulijer 2016) and now Kosovo complements the known range of the
species in the Balkan Peninsula with Albania now being the only country without
published data on the species presence.
L. occidentalis probably arrived in Kosovo through natural expansion from neigh-
boring countries, in some of which it was known several years before (Hradil 2008;
Protić 2008). Species discovery at multiple locations in different regions of Kosovo
Dejan Kulijer, Halil Ibrahimi: First report of invasive species Leptoglossus occidentalis in Kosovo (Heteroptera: Coreidae)
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Fig. 2: Leptoglossus occidentalis Heidemann at Visoki Dečani/Deçan. Photo: D.
Kulijer.
suggests existence of an established population in the country, and not accidentally
introduced individuals. It is too early to say if or what will be the effect of the western
conifer seed bug to commercial forestry in Kosovo. So far in Europe there are no re-
ports on any major damage to conifer seed orchards or forests (Rabitsch 2008). Future
monitoring of this invasive species is needed as mass development could represent
serious threat to the forests and seed production in forestry. 
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Received / Prejeto: 31. 3. 2017
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