1. DISTRIBUTION

T. cyanea is a common wasp in the whole of the Netherlands ^{[1, 5]}. In the garden it is a resident species that is present every year in smaller numbers.

2. BEHAVIOR

2.1. ACTIVITY

The species is active between April and October ^[5].

2.2. DEVELOPMENT

Like all cuckoo wasps this species is a parasite. In the garden it’s host is at least Trypoxylon digger wasps that nest in the bee hotel and there they can be found most often.

The larvae are paraitoids on the host larvae meaning they eat them. 

3. IDENTIFICATION

It is a small wasp measuring 4 – 8 mm ^[2].

The primary characteristics of the species are ^[2]:

1. Antenna scapus lies deep in the frons
2. Keel (carina) on frons

3. Tergite III rear edge pointed like a trident, teeth can be small

4. Small black spots on sternite II

5. Vein of marginal cel is straight and continues up to the wing edege

6. Body metallic blue-green
7. Male sometimes have a black back or are seldom almost completely black (not shown in photo)

4. PARASITIC RELATIONS

T. cyanea is a parasitoid parasite on the following species in the garden:

• Trypoxylon figulus ^[2,3,4,6]
• Trypoxylon attenuatum ^{[3,6,8,9,10,11,12]}

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References

¹ Nederlands Soortenregister

² PAUKKUNEN, Juho, et al. An illustrated key to the cuckoo wasps (Hymenoptera, Chrysididae) of the Nordic and Baltic countries, with description of a new species. ZooKeys, 2015, 548: 1.

³ TORMOS, J., et al. Description of the mature larvae of Chrysis gracillima and Omalus biaccinctus and new data on the biology of Trichrysis cyanea (Hymenoptera: Chrysididae). Florida Entomologist, 1996, 79.1: 56.

⁴ PAERN, Madli, et al. Host specificity of the tribe Chrysidini (Hymenoptera: Chrysididae) in Estonia ascertained with trap-nesting. EJE, 2015, 112.1: 91-99.

⁵ Waarneming.nl

⁶ Peeters, T.M.J., C. van Achterberg, W.R.B. Heitmans, W.F. Klein, V. Lefeber, A.J. van Loon, A.A. Mabelis, H. Nieuwen-huijsen, M. Reemer, J. de Rond, J. Smit, H.H.W. Velthuis, 2004. De wespen en mieren van Nederland (Hymenoptera: Aculeata). – Nederlandse Fauna 6. Nationaal Natuurhistorisch Museum Naturalis, Leiden, knnv Uitgeverij, Utrecht & European Invertebrate Survey – Nederland, Leiden.

⁷ Koch, F. (2002), Blösch, M. (2000). Die Grabwespen Deutschlands – Lebens‐weise, Verhalten, Verbreitung. 71. Teil. In Dahl, F.: Die Tierwelt Deutschlands. Begr.: 1925. – Keltern (Goecke & Evers). – 480 S. 341 Farbfotos. ISBN 3‐931374‐26‐2 (hardcover). DM 98,–. Zool. Reihe, 78: 353-353. https://doi.org/10.1002/mmnz.20020780208

⁸ Asís, J. D., Tormos, J., & Gayubo, S. F. (1994). Biological Observations on Trypoxylon attenuatum and Description of Its Mature Larva and Its Natural Enemy Trichrysis cyanea (Hymenoptera: Sphecidae, Chrysididae). Journal of the Kansas Entomological Society, 67(2), 199–207. http://www.jstor.org/stable/25085509

⁹ WOYDAK, Horst. Hymenoptera Aculeata Westfalica Familia: Sphecidae (Grabwespen), 1996, 3-135.

¹⁰ LOMHOLDT, O. 1975-1976; 1984 (2. Auflage). The Sphecidae (Hymenoptera) of Fennoscandia and Denmark. Fauna Entomologica Scandinavica, 4.1: 2.

¹¹ DANKS, Hugh V. Biology of some stem‐nesting aculeate Hymenoptera. Transactions of the Royal Entomological Society of London, 1971, 122.11: 323-395.

¹² TORMOS, J., et al. Ecology of crabronid wasps found in trap nests from Spain (Hymenoptera: Spheciformes). Florida Entomologist, 2005, 88.3: 278-284.