New species of enigmatic African wasps

As part of discovery and exploration of the extremely species rich, yet largely unknown wasp fauna in Africa, we recently described a number of new species of parasitoid wasps in the superfamilies Chalcidoidea and Ichneumonoidea, including the first records of two genera for Africa: Tanaostigma (Tanaostigmatidae) and Setelacher (Eulophidae), and elucidation of the complex biological host relationship with ants for the genus Eucharissa (Eucharitidae), as well as description of four new species of a rare endemic African genus Tetractenion (Ichneumonidae).

Mandibles and habitus of Tanaostigma lasallei van Noort, 2020 belonging to the rare parasitoid wasp family Tanaostigmatidae. Note the scale bar, the mandibles are each about a tenth of a millimeter in size! Photographs © Simon van Noort (Iziko Museums of South Africa).

Three of the new species were named in honour of the memory of John LaSalle in two papers forming part of a special memorial volume published in the Journal of Natural History. The South African Tanaostigma lasallei was named in memory of John who sadly passed away well before his time. We bestowed this honour in recognition of John’s immense contribution towards the field of chalcidoid systematics and entomology in general (175 peer-reviewed publications). John was a former director of the Australian National Insect collection (CSIRO), and subsequently Director of the Atlas of Living Australia, where he was instrumental in driving the development of this renowned bioinformatics resource. A second species from Kenya was also named after John LaSalle: Tanaostigma ukumbusho. The species epithet ‘ukumbusho’ is Swahili (a widely spoken East African language) for ‘memorial’, and was chosen to also honour the memory of John LaSalle. This honour was particularly pertinent since John’s PhD thesis was conducted on the systematics of World Tanaostigmatidae. This was the first record of the genus from Africa. Biology of these species is unknown, but other species in the family are gall formers on plants in the family Leguminosae.

Setelacher lasallei Gumovsky and van Noort, 2020. Photographs © Alex Gumovsky (Schmalhausen Institute of Zoology, Kyiv, Ukraine).

A further species, Setelacher lasallei belonging to the subfamily Eulophinae (Eulophidae) was also named in honour of John. Eulophids are parasitoids of a range of other insect larvae including flies, butterflies and moths, beetles, true bugs and other wasps. The new species is only known from the tropical region of Africa (Central African Republic, Gabon, and Uganda) from where it was collected by Simon van Noort and Alex Gumovsky during expeditions to the region.

Sampling sites in central African tropical rainforest: Kibale National Park, Uganda (A–C. Photographs © Simon van Noort); Semuliki National Park, Uganda (D, E. Photographs © Alex Gumovsky).

Sampling sites in central African tropical rainforest: Réserve Spéciale de Forêt Dense de Dzanga-Sangha, Central African Republic (F); Parc National de Dzanga-Ndoki, Central African Republic (G); Réserve des Monts Doudou, Gabon (H, I). Photographs © Simon van Noort.

Species of Eucharitidae are all parasitoids of the immature stages of ants. On hatching from the egg the first-stage larvae, called planidia, are carried into the nest by worker ants. Here the wasp larvae attack and parasitize the host ant larva, but halt development until the host pupates. After emerging from the host ant pupa the adult wasp deceives the ants using chemicals that mimic the ant pheromones and are subsequently carried out of the nest by the workers. During field work conducted in the Graskop area by Nokuthula Mbanyana-Nhleko and Simon van Noort a new species was collected from a Bothroponera (Ponerinae) ant nest and subsequently described as Eucharissa insolita, along with the elucidation of the species’ biology, the first unveiling of this for the genus.

Eucharissa insolita Heraty, Mbanyana, van Noort, 2020. Photographs © John Heraty (University of California, Riverside).

The rare endemic Afrotropical genus Tetractenion was previously represented by two described species, Tetractenion acaule and Tetractenion luteum described in the 1930’s. We described four new species: Tetractenion ibayaensis, Tetractenion pascali, Tetractenion pseudolutea and Tetractenion rosei and developed well-illustrated identification keys to the species and to genera of Banchinae occurring in Africa. Biology of the genus is unknown, but other banchines are parasitoids of the immature stages of butterflies and moths (Lepidoptera), beetles (Coleoptera), or other wasps (Hymenoptera).

Clockwise from top left: Tetractenion ibayaensis Reynolds Berry & van Noort, 2020 (Tanzania); Tetractenion pascali Reynolds Berry & van Noort, 2020 (Namibia, South Africa); Tetractenion pseudolutea Reynolds Berry & van Noort, 2020 (Angola, Cameroon, Namibia, South Africa); Tetractenion rosei Reynolds Berry & van Noort, 2020 (Cameroon). Photographs © Terry Reynolds Berry (Iziko Museums of South Africa).

Authors

Simon van Noort is Curator of Entomology having conducted research on wasp systematics and evolution at Iziko since 1992.

https://www.iziko.org.za/researcher/simon-van-noort
http://www.figweb.org/Research/Laboratories/van_Noort/index.htm
https://www.researchgate.net/profile/Simon_Noort