Scale insect host ranges are broader in the tropics

Area of Science:

• Ecology
• Evolutionary Biology
• Entomology

Background:

• Plant-consumer interactions exhibit variable specificity, with unclear evolutionary and ecological drivers.
• Latitude-correlated factors like plant species richness and herbivory intensity may influence this variation.

Purpose of the Study:

• To investigate the effect of latitude on host range in scale insects using comparative phylogenetic methods.
• To understand the factors driving variation in plant-consumer interaction specificity.

Main Methods:

• Comparative phylogenetic analyses were employed to examine host range variation.
• The study focused on scale insects and their host plant associations across different latitudes.

Main Results:

• Scale insects at lower latitudes demonstrate broader host ranges (polyphagy) on average.
• This finding contrasts with the general trend of increased host-plant specificity observed in tropical insects.
• Geographic location significantly impacts insect host range across diverse insect groups.

Conclusions:

• The observed polyphagy in lower-latitude scale insects may be linked to high costs of host specificity, potentially due to life history traits like wind-driven dispersal.
• Geographical factors appear to exert a stronger influence on insect host range than genetic trade-offs.