Abstract. When estimating the species richness of a taxonomic group in a specific area, the choice of the trapping method is extremely important. In this study the effectiveness of Malaise and Moericke yellow pan traps for collecting flying Ichneumonidae was compared. Samples were collected in 5 habitats in the Cabañeros National Park: pastureland, shrubland and three types of woodland. Two traps of each type were placed in each habitat, and samples collected over a period of one year, replacing the pots every 20 days. The study focused on eleven subfamilies of Ichneumonidae. The results showed that the composition of the Ichneumonidae in the catches of the two traps differed. Malaise traps were more effective in collecting Ichneumonidae in all habitats, but especially in the ash woodland. Moericke traps yielded the most abundant catches in open areas with a wider field of vision. The subfamily Orthocentrinae occurred more frequently in the Moericke yellow traps. The Ichneumonidae caught by both trapping methods differed, especially in the relative abundance of the most common species. When compiling an inventory of species it is extremely important to use a combination of both trapping methods.

Utilising short‐term but geographically extensive sampling in Guatemala, Honduras, and Nicaragua, we examined altitudinal trends in species richness and diversity of ichneumonid parasitoid wasps. This study covered 19 subfamilies, including four globally large subfamilies that have not yet been taxonomically revised in the Neotropics. Sampling was done at 25 sites classified into three elevational categories on the basis of the average elevation of traps at each site (low 34–659 m a.s.l., middle 1033–1709 m a.s.l., and high 1930–2565 m a.s.l.). A total of 2847 ichneumonid individuals were captured and sorted into 751 morphospecies, most of which were identified to the genus level. We found a clear compositional gradient in ichneumonid communities along the elevational gradient, as the majority of species were restricted to either one elevational zone or two adjacent zones. In our data, mid‐ and high‐elevation sites had generally higher ichneumonid species richness and diversity than low‐elevation sites. These trends were largely similar to those found in larger scale Mesoamerican ichneumonid studies. Yet, the low ichneumonid richness at low elevations may partly be a sampling artefact. This provides a new piece of evidence for the suggestion that extensive sampling is needed for uncovering the real diversity of ichneumonids in tropical lowland forests, and that the reputation of Ichneumonidae as a notable example of a reversed latitudinal diversity gradient may be undeserved.

Epirhyssa Cresson 1865 is a large tropical genus of the family Ichneumonidae. It is the most diverse genus of the subfamily Rhyssinae with about 118 species worldwide. In this study we conducted four long-term field inventories to review the Peruvian Amazonian species of the genus. We provide illustrations, diagnosis and an identification key to the species currently known to occur in the region, including descriptions of 10 new species. In addition, we describe the female of E. wisei Porter and the male of E. pertenuis Porter, discuss the biogeographical patterns of species richness of the genus and provide new faunistic records for Brazil, Colombia, Ecuador, French Guiana, Paraguay and Peru. The Peruvian Amazonia is, according to our results, among the most species-rich areas in the world for this genus. Some of the new species described in this work were named by the public in Finland and Peru during two innovative competitions to name these beautiful species. The aims of these competitions were to draw attention to the plethora of unknown species lurking in the shades of tropical forests and the necessity to protect these highly diverse areas.

Ateleutina is a small subtribe of Cryptinae (Ichneumonidae) composed of two genera: Ateleute Förster and Tamaulipeca Kasparyan. Neither of the genera includes species described from South America. In this article five new species of Ateleute (A. ashaninka sp. n. and A. amarakaeri from Peru, A. shuar sp. n. from Ecuador and Peru, and A. huaorani sp. n. and A. kichua sp. n. from Ecuador) and three new species of Tamaulipeca (T. bora sp. n. from Ecuador and Peru, T. candoshi sp. n. from Ecuador and T. matses sp. n. from Peru) are described and illustrated from Western Amazonia. Identification keys to the known South American species of the genera are provided.

A checklist of the Peruvian Ichneumonidae (Hymenoptera) is provided. A total of 391 species, in 134 genera and 20 subfamilies, are reported. Of these, 139 species are only known from Peru, and 48 represent undescribed species. This work reports nearly 53% more taxa than the checklist compiled by Francisco Carrasco (1972), representing a much needed update of that work. The checklist is updated to September 2009.