The species richness of pimpline ichneumonids was examined using catches from a network of Malaise traps operated throughout Costa Rica. More species were caught at some sites than at reasonably well-collected sites in other countries. When corrected for area, the species richness of ‘Pimplinae’ and Pimplini in Costa Rica as a whole is greater than that for virtually any other region recorded to date. The local richness of both groups appears to be a function of their regional richness. Many of the species found in Costa Rica apparently have large geographic ranges.
