Biogeographical Patterns of Earwigs in Italy

Area of Science:

• Zoology
• Biogeography
• Ecology

Background:

• Italy's position in the Mediterranean biodiversity hotspot makes it crucial for European biogeography.
• The Italian earwig fauna comprises widespread Palearctic species and endemic Alpine/Apennine species.

Purpose of the Study:

• Investigate the influence of climatic, spatial, and historical factors on Italian earwig species richness and composition.
• Determine the drivers of earwig biodiversity patterns in Italy.

Main Methods:

• Analysis of earwig species richness and composition across Italy.
• Correlation of biodiversity patterns with climatic, spatial, and historical data.

Main Results:

• Species richness showed no clear geographical pattern but was positively influenced by precipitation, aligning with earwigs' preference for humid climates.
• A southward decrease in similarity with Central European fauna was observed, but no significant peninsula effect.
• Geographical proximity was the primary driver of species composition variation, with climate and historical events playing minor roles.

Conclusions:

• The isolation of ancient earwig lineages in Italian mountains has led to a significant number of endemic species.
• Italy harbors one of Europe's richest earwig faunas, shaped by a combination of climate and geographical factors.
• Southern Italy did not play a key role in determining current species richness patterns during Pleistocene glaciations.