• Amazonia;
  • anomalous latitudinal diversity gradient;
  • Ichneumonidae;
  • local species richness;
  • lowland rainforest;
  • non-parametric species richness estimating;
  • Peru

Abstract.  1. The parasitic wasp family Ichneumonidae (Hymenoptera) is of great interest because it has been claimed that its species richness does not increase with decreasing latitude.

2. No extensive studies of the family have been conducted in South American localities.

3. Arthropods were sampled using 27 Malaise traps in the Allpahuayo–Mishana National Reserve (56 000 ha) in the north-eastern Peruvian Amazonian lowland rainforest. The total duration of the sampling programme was 185 Malaise trap months.

4. Altogether, 88 species were collected. This is one of the highest local pimpline and rhyssine species numbers ever recorded. A comparison with results from Mesoamerica revealed that at equal numbers of individuals sampled, the number of Pimplinae and Rhyssinae species in Peruvian Amazonia is at least twofold compared with lowland locations in Mesoamerica and somewhat higher than in the most species-rich Costa Rican higher altitude localities.

5. Non-parametric methods of estimating species richness were applied. These suggest that additional sampling would yield a considerable number of new Pimplinae and/or Rhyssinae species.