Ichneumonidae

Classification of Afrotropical Ichneumonidae

South African Ichneumonidae

A manipulative ichneumonid wasp

David Wahl's classification and systematics of world Ichneumonidae 

Aim of this web site

An E-typing initiative to photographically document the type specimens of Afrotropical ichneumonids to facilitate the identification of specimens collected during biodiversity inventory surveys. Types of 604 species, representing 314 of the 338 Afrotropical genera, have so far been photographed in European museums and web pages are currently being developed for these species. Species pages can be accessed through the Classification pages. Online keys are currently being developed.

Ichneumonid species richness

The Ichneumonidae is one of the most species rich families of all organisms with an estimated 60 000 species in the world (Townes 1969). Even so, many authorities regard this figure as an underestimate! (Gauld 1991). An estimated 12 100 species of Ichneumonidae occur in the Afrotropical region (Africa south of the Sahara and including Madagascar) (Townes & Townes 1973), of which only 1 927 have been described (Yu 2011). This means that roughly 16% of the Afrotropical ichneumonids are known to science! These species comprise 338 genera. The family Ichneumonidae is currently split into 37 subfamilies, of which 24 have been recorded from the Afrotropical region (Yu 2011).

Ichneumonid diversity assessment in Africa

Quantitative studies of ichneumonid species richness are scarce in Africa. A limited number of assessments have been conducted in Sierra Leone and Uganda (Owen & Owen 1974); Namibia (van Noort et al. 2000); Gabon (van Noort 2004); Central African Republic (van Noort in prep.), Tanzania (van Noort in prep.) and South Africa (van Noort in prep.).  Very little is known about the ichneumonid faunas of the majority of African countries.

Latitudinal gradients of ichneumonid species richness

The Ichneumonidae, along with other groups of parasitic Hymenoptera, are supposedly no more species rich in the tropics than in the Northern Hemisphere temperate regions (Owen & Owen 1974; Janzen 1981; Janzen & Pond 1975), although a number of hymenopteran families, for example the Chalcididae (Hespenheide 1979) and Encyrtidae (Noyes 1989b) exhibit an increase in species richness with a decrease in latitude. Other hymenopteran taxa such as sawflies (Symphyta), gall-forming Cynipidae and bees (Apoidea) peak in species richness at mid or high latitudes (Michener 1979; Noyes 1989b; Kouki et al. 1994). Considerable debate has centered on the apparent species richness anomaly exhibited by a number of hymenopteran parasitoid taxa in the tropics (see Morrison et al. 1978; Gauld 1991; Gauld & Gaston 1994).

Importance of ichneumonids

Ichneumonids utilise a diverse array of insects and arachnids as their hosts and play an essential role in the normal functioning of most ecosystems, underlining the need to inventory their diversity. Ichneumonids have been used successfully as biocontrol agents and given the largely undocumented fauna there is a huge potential for their use in managed biocontrol programmes (Gupta 1991). Comprehensive quantitative biodiversity surveys will enable the identification of hotspots of species richness and endemism; essential base line data that will enable informed future conservation management decisions.

Web author Simon van Noort (Iziko South African Museum)

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