Distribució i grau d’invasió de la formiga argentina (Linepithema humile Mayr) (Hymenoptera: Formicidae) al Parc Natural de s’Albufera des Grau, Menorca (Illes Balears)

The Argentine ant is an exotic invasive species present in all the
Mediterranean and subtropical ecosystems of the world. It is closely associated to
urban and human-disturbed areas, even though it can also invade natural areas
causing a strong negative effect in the biodiversity of the invaded area. In
Menorca, the fist record of its presence was in 1976. In 2004 it was detected for
the first time invading a natural area in the island, the s’Albufera des Grau Natural
Park. The aim of this work is to determine both the distribution and degree of
invasion of this species into the Park. To that effect, we sampled a total of 97 plots
of 1 ha at 8 different areas across the Park. Of these, only 15 resulted invaded by
the Argentine ant with different degrees of invasion. Additionally, we also detected
4 forefronts of invasion. Both the presence and degree of invasion into the
s’Albufera des Grau Natural Park seems to be related to four factors: 1) degree of
canopy cover, 2) proximity to urban or certain urban development areas, 3) degree
of anthropic frequentness and 4) proximity to humid areas. The results obtained in
this study allow getting basic information to elaborate further research about the
real effects of the invasion in the biodiversity of the area