Invasive insects outperform their native counterparts

Invasive alien species cause substantial ecological damage worldwide, driving biodiversity loss and negatively impacting human livelihoods. Although invasive insects have some of the most severe impacts, the traits associated with their invasiveness remain unclear.

We conducted a meta‐analysis comparing phenotypic traits of matched, co‐occurring invasive and native insect pairs (sympatric congeners or confamilials) in the invaded range. In total, we compared 922 invasive‐native pairs using 1327 effect sizes from 182 studies. These pairs comprised 144 unique invasive insect species and 403 unique native species.

We found that invasive insects generally have greater fecundity, shorter development times, faster population growth rates and enhanced foraging and competitive capabilities compared with their native counterparts. However, some of these patterns changed after excluding the two most data‐rich families (i.e. Coccinellidae and Formicidae), likely due to divergent evolutionary histories, life history strategies and selection pressures.

This study represents the most comprehensive systematic comparison of trait differences between co‐occurring native and invasive insect species and highlights that a diverse array of traits can contribute to invasiveness. Moreover, our open‐access database of insect trait data will facilitate further research into the causes and consequences of insect invasions.