Assessing alpha and beta taxonomy in eupelmid wasps: determinants of the probability of describing good species and synonyms

We analysed the status of the taxonomical knowledge on Afrotropical and Palaearctic Eupelmidae (Hymenoptera, Chalcidoidea), by assessing the historical accumulation of valid new species and synonyms through time, as well as the factors that have determined the process of description of good species and synonyms in these regions. The species accumulation curves for valid species names show that a significant proportion of the taxa remains to be described in both areas. On the contrary, the historical accumulation of synonymic names seems to reach an asymptote in both areas, although the proportion of synonyms compared with the total number of names is higher in the Palaearctic region. We assessed factors ifluencing the probability of a species being discovered and the probability of being described several times under different names. Both probabilities seem to be affected by the same factors. Distribution range size and geographical location of taxa affect both the processes of discovering good species and producing synonyms in either region. Models using all these predictors explain (1) 36% and 40% of the variance in the year of description of valid names for the Afrotropical and Palaearctic regions respectively, and (2) 56% and 40% of the variation in the number of synonyms per valid species in these two areas. For the species with available information, trophic specialization is also a significant determinant of these probabilities. However, its effect is also accounted for by geographical range size, which can thus be used as a surrogate of the ecological correlates of discovery and redundant description probabilities. In general, the ecologically generalist, widely distributed and early described taxa living in northern and western areas of both regions have been subject of redundant description more times. Further, taxonomical effort is needed in the south and east of the Palaearctic, as well as in the whole of the Afrotropics, where additional effort in a revision of Eupelmid systematics is needed.