Invasive alien insects represent a clear but variable threat to biodiversity.

Area of Science:

• Ecology
• Conservation Biology
• Invasive Species Research

Background:

• Biological invasions, particularly by alien insects, pose a significant threat to global biodiversity.
• Quantifying the environmental impacts of invasive insects is crucial for effective conservation strategies.
• Existing research often lacks comprehensive data on the scope and severity of insect invasions.

Purpose of the Study:

• To quantify the breadth and level of environmental threats posed by invasive alien insects.
• To test hypotheses regarding socioeconomic and taxonomic biases, range size-impact relationships, and island susceptibility.
• To assess the largest effort to date in quantifying the environmental impacts of invasive alien insects.

Main Methods:

• Utilized a modified Environmental Impact Assessment for Alien Taxa (EICAT) framework.
• Analyzed a large, taxonomically representative set of established invasive insect species globally.
• Tested specific hypotheses related to invasion impacts and biases.

Main Results:

• Species with larger introduced ranges were more likely to exhibit severe local environmental impacts ('Major').
• The hypothesis of increased island susceptibility to invasive insects was not supported; both islands and mainlands experience similar high-severity impacts.
• Impact information was found to be skewed geographically and taxonomically, with socioeconomic pests having marginally more data.

Conclusions:

• Invasive insects exhibit high variability in their impact on biodiversity, even among well-known invaders.
• The current knowledge base on invasive insect impacts necessitates greater taxonomic and geographic expansion.
• Further research is needed to identify general patterns in the biogeography of invasion impacts.