Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

ICHNEUMONIDAE: : Rhyssa Gravenhorst 1829


Characteristics of Rhyssa include: 1. Body size mostly >20mm but occassionally 10-20mm; 2. Position of spiracle on T1 at, close to, or before centre; 3. Shape of aerolet in forewing triangulate; 4. Colour of face is not all black; 5. Metasoma compressed somewhat laterally; 6. Size of ocelli small; 7. Length of antennae is shorter than body; 8. Length of ovipositor is as long, or longer than body; 9. Wings present ; 10. Colour of wings hyaline (clear); 11. Sternaulus absent; 12. Shape of face in lateral view flat or only weakly bulging; 13. Sternite on T1 (viewed laterally) not extending past spiracle; 14. Shape of T1 (viewed laterally) evenly curved; 15. Number of teeth in mandibles 2; 16. Metasoma with colourful spots; 17. Length of T1 less than T2 or subequal in length; 18. Sculpture on mesoscutum with transverse striations (wrinkles); 19. Width of T1 (viewed dorsally) of uniform width (slightly widening posteriorly); 20. Glymma on T1 present (deep pit); 21. Sculpture on metasoma is smooth with a semi-glossy or satin appearance at least on T2; 22. Propodeum very short (not reaching beyond coxal insertion).

Similarity to Other Taxa

Rhyssa are large-sized Ichneumonids in New Zealand. It is similar in size to: Lissopimpla , Echthromorpha , Ophion (1 species), Enicospilus , Eutanyacra , Ichneumon , Netelia , Xanthocryptus , Ctenochares , and Degithina .

Rhyssa are most similar to Echthromorpha but do not have a black patch in the forewing, and the ovipositor in Rhyssa is as long(er) than the body.


Distribution in NZ

North Island: AK, BP, HB, WI, WA. South Island: NN, BR, MC.

Species in NZ

Two species: Rhyssa persuasoria persuasoria (Linnaeus 1758) a biological control agent introduced to contol Sirex . Rhyssa lineolata (Kirby 1837) is an accidental introduction but also attacks Sirex .

Biology & hosts

Rhyssa is a small genus, which are common parasites of woodwasps (Hymenoptera: Siricidae) in the north temperate (Gauld 1984).

Rhyssa persuasoria was introduced into New Zealand from England in 1928-1931 for the control of Sirex wood wasp (Nuttall 1980). Together, with other parasitoids and parasites, it achieves very good control. Rhyssa lineolata is an accidental introduction but also attacks Sirex (Zondag & Nuttall 1961).

Overseas, Rhyssa persuasoria and Rhyssa lineolata have a wider host range attacking a range of wood-boring Coleoptera (Buprestidae, Cerambycidae, Melandryidae) and Hymenoptera (Siricidae: Sirex , Urocerus , Xeris ) (Yu et al. 2005).

Sources of information

Gauld ID. 1984. An Introduction to the Ichneumonidae of Australia. London, British Museum (Natural History). 413 p.
Nuttall MJ. 1980. Insect parasites of Sirex (Hymenoptera: Ichneumonidae, Ibaliidae, and Orussidae). Forest Timber Insects in New Zealand 47. Forest Research Institute, New Zealand Forest Service. 12 p.
Parrott AW. 1952. New Zealand Ichneumonidae. II. Tribe Echthromorphini (Pimplinae). Transactions of the Royal Society of New Zealand (Zoology) 80: 155-170.
Parrott AW. 1962. Notes and synonymy of New Zealand Ichneumonidae. Subfamily Pimplinae. Transactions of the Royal Society of New Zealand (Zoology) 1: 349-353.Yu DS, van Achterburg K, Horstmann K. 2005. World Ichneumonoidea 2004. Taxonomy, Biology, Morphology and Distribution. CD/DVD. Taxapad. Vancouver, Canada.
Zondag R, Nuttall MJ. 1961. Rhyssa lineolata (Kirby) (Hymenoptera; Ichneumonidae; Pimplinae). A species new to New Zealand. New Zealand Entomologist 2: 40-44.


Ward DF & Schnitzler FR. 2013. Ichneumonidae of New Zealand. Genus Rhyssa
Accessed: 14 August 2020


v1.0. Ward DF & Schnitzler FR. 2013