ICHNEUMONIDAE: : Phytodietus Gravenhorst 1829
Spiracle is at or before the centre of T1, a deep glymma on T1, the ovipositor length distinct but not longer than the body, a petiolate areolet in the forewing
Diagnosis:Phytodietus is relatively simple to identify. There are very few taxa it can be confused with. However, it is not commonly encountered. It has a relatively distinct body colouration, with very yellow hind femora and black hind tibia.
Characteristics of Phytodietus include: 1. Body size just slightly <10mm; 2. Position of spiracle on Tergite 1 is at the centre; 3. Shape of aerolet in forewing is petiolate; 4. Colour of face is not all black; 5. Metasoma is compressed laterally; 6. Ocelli are small; 7. Length of antennae are as long as the body; 8. Length of ovipositor is distinct but not longer than body; 9. Wings are present; 10. Colour of wings are hyaline (clear); 11. Sternaulus (on mesopleuron) is absent; 12. Shape of face in lateral view is flat or only weakly bulging; 13. Sternite on T1 (viewed laterally) is not extending past spiracle; 14. Shape of T1 (viewed laterally) is evenly curved; 15. Number of teeth in mandibles is 2; 16. Patterns on metasoma is the same colour throughout (black, dark brown); 17. T1 longer than T2; 18. Sculpture on mesoscutum is smooth, very polished; 19. Width of T1 (viewed dorsally) is generally of uniform width (slightly widening posteriorly); 20. Glymma on T1 is present as a deep pit that produces a small hole in T1; 21. Sculpture on metasoma is smooth with a glossy appearance (highly polished, no punctures); 22. Propodeum reaching just past the coxal insertion, but not reaching halfway along metacoxae.
Similarity to Other TaxaPhytodietus is a mid-sized Ichneumonid in New Zealand. They are siimilar in size to: Dusona , Liotryphron , Habronyx , Lissonota and Venturia . It can be separated from other similar sized taxa by having a deep glymma on T1, the ovipositor length distinct but not longer than the body, a petiolate areolet in the forewing.
T1 squat, dorso-ventrally compressed ( Phytodietus is laterally compressed).
Glymma present as groove (not deep pit), ovipositor as long as body, mesoscutum not polished but finely pitted.
Ovipositor length very short, spiracle on T1 well behind the centre of T1.
Ovipositor length very short, no areolet in forewing, spiracle on T1 well behind the centre of T1.
Metasoma bicoloured (orange/black), spiracle on T1 well behind the centre of T1.
Phytodietus can be separated from Netelia, the only other genus of Tryphoninae in New Zealand, by being a smaller size, having yellow/brown/black body colouration (vs brown throughout), and having small ocelli. Both species of Netelia are well over 10mm in length and have very large ocelli.
Distribution in NZ
North Island: AK, BP, CL, GB, HB, TO, WN, RI. South Island: NN, BR, MC, DN, CO, WD, FD, SI, SL.
Species in NZOne endemic species Phytodietus zealandicus (Ashmead 1900).
Biology & hostsPhytodietus is a large cosmopolitan genus around the world, but the New Zealand species is placed in its own subgenus, Euctenopus . Little is known about the biology or host of Phytodietus zealandicus , however, it is nocturnal. It is widespread in New Zealand and has also been collected from a wide range of habitats, such as urban areas, beech forest, swamps, and coastal lagoons/beaches.
Sources of informationGauld ID 1984. An Introduction to the Ichneumonidae of Australia. London, British Museum (Natural History). 413 p.
Parrott AW. 1951. New Zealand Ichneumonidae. I. The genus Netelia Gray. ( Paniscus of authors) (Tryphoninae: Phytodietini). Transactions of the Royal Society of New Zealand (Zoology) 79: 286-293.
CitationWard DF & Schnitzler FR. 2013. Ichneumonidae of New Zealand. Genus Phytodietus http://ichneumonidae.landcareresearch.co.nz
Accessed: 13 August 2020