Differences in straggling rates between two genera of dove lice (Insecta: Phthiraptera) reinforce population genetic and cophylogenetic patterns.
Two competing views have been expressed to explain ectoparasite speciation patterns, one emphasizing co-speciation and one emphasizing host-switching. Though recent authors preferred a combination of these views, the available phylogenetic trees cannot be interpreted without revisiting island biogeography theory. Parasite extinction due to a temporal decline in host population size seems to be a prerequisite of subsequent speciation by host-switch. The need for a re-evaluation of "stragglers" (ectoparasites found on non-specific hosts) is emphasized.