Figure 3.

The type species (the first described in a genus) has a statistically significantly higher average host range than those that follow. Parasites described earlier typically have a higher degree of generalism (greater number of recorded hosts), especially prior to the 1840s; specimens collected after roughly the 1870s also apparently tend towards more host-specific species than those from older collections. (Curves are generalized additive models fit assuming a negative binominal distribution, with dashed lines for the 95% confidence bounds.) (Online version in colour.)