Data from: Scale insect host ranges are broader in the tropics

The specificity of the interactions between plants and their consumers
varies considerably. The evolutionary and ecological factors underlying
this variation are unclear. Several potential explanatory factors vary
with latitude, for example plant species richness and the intensity of
herbivory. Here, we use comparative phylogenetic methods to test the
effect of latitude on host range in scale insects. We find that, on
average, scale insects that occur in lower latitudes are more polyphagous.
This result is at odds with the general pattern of greater host-plant
specificity of insects in the tropics. We propose that this disparity
reflects a high cost for host specificity in scale insects, stemming from
unusual aspects of scale insect life history, for example, passive
wind-driven dispersal. More broadly, the strong evidence for pervasive
effects of geography on host range across insect groups stands in stark
contrast to the weak evidence for constraints on host range due to genetic
trade-offs.