Steel blue cricket hunter
| Steel blue cricket hunter | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Steel blue cricket hunter ( Isodontia mexicana ) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Isodontia mexicana | ||||||||||||
| ( Saussure , 1867) |
The steel-blue cricket hunter ( Isodontia mexicana ) is a digger wasp from the family Sphecidae .
features
The animals are 15 to 20 mm long, males are slightly smaller than females. The body, including the legs, is a solid black color, only the posterior tibiae can rarely be lightened reddish. The wings are blackish smoky and clouded, with a striking blue shimmer when light falls from the side. The animals have a long stalked abdomen, the stalk segment (petiolus) is clearly curved downwards and reaches the length of the first segment of the hind tarsi. The hind tarsi are remarkably long and brightly hairy. The front of the head (part of the face) is completely covered with thick black bristles. The species differs from the Sphecinae with a long stalked abdomen, native to Central Europe, by the blue wing reflexes and the lack of red or yellow colored body sections. In the similar, very rare Chalybion femoratum , the body is blue-green with a metallic sheen and the hind legs of the female are red. The species is unmistakable in Central Europe and is the only Isodontia species here , but some autochthonous species of the genus live in Southeastern Europe .
distribution
Isodontia mexicana is originally from Central and North America. The species occurs throughout North America east of the Rocky Mountains, but is rare in the southwest (only recorded from southern Arizona and Sonora, Mexico). The species was introduced to the south of France in the 1960s. From here it spread over large parts of southern Europe and is now one of the most common digger wasp species on the southern side of the Alps. The species is distributed over the south of France, Spain, all of Italy and large parts of the northern Balkan Peninsula and is spreading rapidly. It is still missing in the north of France (north about to the Lot department). It was first detected in England in 2016. It occurs in the Southern Alps up to around 1000 meters above sea level.
In Central Europe, large parts of Austria and Switzerland, north to the state of Salzburg and Lucerne, are settled. It was first detected in Germany in 1998. Observations are available from Kehl near Strasbourg and from the Kaiserstuhl as well as from the Mooswaldsiedlung in Freiburg, i.e. from the southern Upper Rhine Plain. The digger wasp species has been represented in the middle Upper Rhine since the end of the 2010s.
Way of life
The species can be found imaginally in mid and late summer. Two successive generations have been recorded in North America. Hibernation takes place as an old larva (prepupa) of the second generation, ready to pupate, within the cavity. Two generations are also suspected in Central Europe. Both males and females can predominate in a single nest, but in principle the gender ratio is around 1: 1. Within a cavity, the females always develop in the deeper, rear cells, so they hatch a little later.
The nest is created in above-ground cavities. Natural and artificial cavities of all kinds are accepted, e.g. B. Reed stalks (especially the giant reed Arundo donax ). The species occurs in America regularly in wild bee nesting aids with pre-drilled holes, which z. B. to promote the alfalfa leaf cutter bee ( Megachile rotundata ). Settlement of the joints in storm coverings for windows is also widespread. In Florida even the hoses of the insect-digesting pitcher plant Sarracenia minor are used.
The species usually creates one to six brood cells one behind the other. The individual brood cells are separated with sections of (withered) grass leaves. This behavior is highly characteristic of the genus Isodontia and does not occur in other digger wasps. At the end, a more or less long tuft of individually entered, mostly wilted grass leaves protrudes from the tube as a plug.
Crickets and grasshoppers serve as prey. The most important prey species in Europe and North America are the Oecanthus flower crickets , in Europe primarily the wine chickens ( Oecanthus pellucens ). In addition, sword horrors of the genus Conocephalus are widely preyed , in Europe especially the widespread long-winged swordfish , which is often associated with the wine-cockerel , and in the southern Upper Rhine Graben especially the delicate common oak horror . The three larval stages are passed through extremely quickly, in four to six days. The pupil rest of the summer generation lasts two to three weeks, pupation takes place in a self-spun cocoon.
Isodontia mexicana nests are often infested with parasites and parasitoids. Fly species of the Phoridae and Sarcophagidae families are often found, feeding on the preyed locusts as kleptoparasites . The digger wasp larva can survive the infestation, but the hatching wasp then remains significantly smaller.
The imaginal wasps are flower visitors. Flowers of goldenrod ( Solidago ) species and man litter ( Eryngium ) are often mentioned, including Eryngium planum , which is often planted in gardens as an ornamental plant .
With prey in front of the nesting aid
With nesting material approaching the nesting aid
Closing the access to the nesting aid
Systematics
Isodontia mexicana was first described by Henri de Saussure in 1867 as Sphex apicalis varietas Mexicana . The genus Isodontia is distributed almost worldwide and comprises 61 species.
swell
- ↑ Klaus Hellrigl (2004): On the distribution of introduced digger wasps (Hymenoptera: Sphecidae) in South Tyrol and Northern Italy. forest observer 1/2004: 181–196.
- ↑ Christian Schmid-Egger (2005): Sceliphron curvatum (F. Smith 1870) in Europe with an identification key for the European and Mediterranean Sceliphron species (Hymenoptera, Sphecidae). Bembix 19: 7-28.
- ↑ Sphecidae at Discover Life: Distribution Map
- ^ Jacques Bitsch (2010): Compléments au volume 2 des Hyménoptères Sphecidae d'Europe occidentale (Faune de France 82). Bulletin de la Société entomologique de France 115 (1): 99-136.
- ↑ http://gwydir.demon.co.uk/insects/WatchList.htm , accessed August 29, 2016
- ↑ The steel-blue cricket hunter (Isodontia mexicana) now also detected in the Kaiserstuhl
- ↑ JT Medler (1965): Biology of Isodontia (Murrayella) mexicana in trap nests in Wisconsin (Hymenoptera: Sphecidae). Annals of the Entomological Society of America, Volume 58, Number 2: 137-142.
- ↑ Klaus Rennwald (2005): Is Isodontia mexicana (Hymenoptera: Sphecidae) already native to Germany? Bembix 19: 41-45.
- ^ Durland Fish: Insect-plant relationships of the insectivorous pitcher plant Sarracenia minor. Florida Entomologist 59 (2): 199-203.
- ↑ O'Neill, KM, O'Neill, JF, O'Neill, RP (2007): Sublethal effect of brood parasitism on the grass-carrying wasp Isodontia mexicana. Ecological Entomology 32: 123-127. doi : 10.1111 / j.1365-2311.2006.00851.x
- ^ Isodontia. In: Wojciech J. Pulawski: Catalog of Sphecidae sensu lato. Download
