The world’s 100 worst invasive alien insect species

While there has been great interest in species characteristics that
promote invasiveness, still little is known about the characteristics that
distinguish invasive from non-invasive insects. Using a database on the
naturalized distributions of alien insects and expert opinions about their
impacts, we identified the world’s 100 worst invasive insect species. By
comparing species characteristics reported in the literature using a
meta-analysis, between the 100 worst invasive species and related
non-invasive species, we found that invasive insects overall have more
pathways of introduction, occur in more habitats, have higher fecundities,
higher voltinism, more genes, shorted lifespans and faster development
from egg to adult. Some of the differences in species characteristics are
related to propagule pressures, life-histories and biotic interactions,
conditional on whether the non-invasive species compared is known to be
naturalized somewhere, whether the invasive species is globally
distributed, and the climatic region of the species. Synthesis and
applications: We show for the first time, using a multi-species
comparative approach, that invasive insects differ in several
characteristics from related non-invasive insects. Our results show that
invasive species, such as Spodoptera frugiperda, typically are habitat
generalists with a high fecundity, a short lifespan, and fast development,
whereas the importance of female body size and number of enemies are
context dependent. Our study can guide and improve existing screening
tools for assessing the invasion potential of alien insects.