ICHNEUMONIDAE: : Gelis Thunberg 1827
Diagnosis:Characteristics of Gelis include: 1. Body size (mm) (excluding antennae and ovipositor):<10mm; 2. Position of spiracle on Tergite 1 (T1 of metasoma):clearly behind the centre; 3. Shape of aerolet in forewing:other; 4. Colour of face:only black; 5. Metasoma compressed:dorsal-ventrally; 6. Size of Ocelli:small; 7. Length of antennae:shorter than body; 8. Length of ovipositor:not longer than body; 9. Wings:present; 10. Colour of wings:mostly clear but with dark patches/spots; 11. Sternaulus (on mesopleuron):short; less than 0.5x length mesopleuron; 11. Sternaulus (on mesopleuron):long; more than 0.5x length mesopleuron; 12. Shape of face in lateral view:flat or only weakly bulging; 13. Sternite on T1(viewed laterally):sternite not extending past spiracle; 14. Shape of T1(viewed laterally):evenly curved; 15. Number of teeth in mandibles:1 or 2; 16. Patterns on metasoma:same colour throughout; 17. Length of T1 vs T2:subequal in length; 18. Sculpture on mesoscutum:finely pitted, many hairs; 19. Width of T1 (viewed dorsally):gradually widening from anterior to posterior; 20. Glymma on T1:absent; 21. Sculpture on metasoma:smooth with a semi-glossy or satin appearance at least on T2; 22. Propodeum length:Propodeum very short (not reaching beyond coxal insertion).
Distribution in NZ
North Island: AK, HB. South Island: NN, MC, CO. Offshore Islands: CA
Species in NZTwo species: Gelis cinctus (Linnaeus 1758), and G. tenellus (Say 1836). Another two species currently assigned to the genus, Gelis philpottii (Brues1922) and G. campbellensis Townes 1964, are probably not in the genus (Valentine & Walker 1991).
Biology & hostsGelis is a very large, northern temperate genus, where the females are wingless and look similar to ants (Gauld 1984). Gelis attack a wide range of small cocoons of various insects including Lepidoptera, Neuroptera and Hymenoptera and the egg sacs of spiders (Gauld 1984). They have been also recorded both as parasites and hyperparasites especially of Coleophorids, Pyralids (Lepidoptera) and Braconids and Ichneumonids (Hymenoptera).
Host records for Gelis cinctus and G. tenellus are very large, with over thirty and sixty recorded hosts, respectively (Yu et al. 2005). The hosts of “Gelis” campbellensis and “Gelis” philpottii are not known.
Sources of informationGauld ID 1984. An Introduction to the Ichneumonidae of Australia. London, British Museum (Natural History). 413 p.
Valentine EW & Walker AK. 1991. Annotated Catalogue of New Zealand Hymenoptera. DSIR Plant Protection Report 4. General Printing Services, 84 p.
Yu DS, van Achterburg K, Horstmann K. 2005. World Ichneumonoidea 2004. Taxonomy, Biology, Morphology and Distribution. CD/DVD. Taxapad. Vancouver, Canada.
CitationWard DF & Schnitzler FR. 2013. Ichneumonidae of New Zealand. Genus Gelis http://ichneumonidae.landcareresearch.co.nz
Accessed: 3 August 2020