Anaxyelidae
| Anaxyelidae | ||||||||||
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| Scientific name | ||||||||||
| Anaxyelidae | ||||||||||
| Martynov , 1925 |
The Anaxyelidae are a family of wood wasps . In addition to numerous fossil species, only one living representative is known, the cedar wasp Syntexis libocedrii . This species is therefore considered a " living fossil ".
features
The living species Syntexis is approx. 10 mm long and black with yellow markings . At the head the maxillary palps are six- limbed , the labial palps three- limbed . The antennae consist of sixteen elongated members. The wing veins are characterized by some reductions, the subcosta is completely missing, a large costal cell is present. The wings are crystal clear with a large dark wing mark ( pterostigma ). The anterior thorax segment ( prothorax ) is short and wide and widened in a trapezoidal shape towards the rear. The spur on the front splint ( tibia ) has clear teeth. The abdomen is high and narrow (flattened on the sides), the characteristic thorn of the wood wasps is missing at the end of the abdomen. At the end of the abdomen, the female wears a relatively short and strong, straight ovipositor with a sawn tip and a round cross-section.
larva
The larva is colored white with a round head capsule with a three-part, short antenna. In adaptation to the way of life within wood, both the thoracic and abdominal legs are largely reduced. At the end of the abdomen, it has a protruding spike that serves as support when gnawing the wood.
Way of life
The species lives on conifers, in the wood of which the larvae drill tunnels. As with many wood wasps, it is dependent on symbiotic fungi for food, which partially break down the wood it has eaten and thus make it digestible for the larvae. The species is pyrophilic and only attacks partially burned dead or partially dead trees immediately after forest fires, which the animals apparently approach from a great distance. Sometimes the eggs should be laid in trees that are still burning or at least smoldering. The most important host plant is the frankincense cedar ( Caloderus decurrens ), along with information on a number of other conifer species. The female bores an egg several centimeters deep into the wood, the hatching larva eats for two, possibly three years and then pupates near the surface of the wood.
Naturally, the way of life of the fossil species cannot be given with certainty. As far as is known, a link to conifer species is plausible.
Occurrence
The recent species lives in western North America, in the states of California, Idaho and Oregon. Fossil species have been found from Russia, Kazakhstan, China, Brazil and England (compression fossils and imprints in limestone) and from Spain (inclusions in amber). Finds are therefore available from both hemispheres, which shows that the family was probably distributed worldwide.
Systematics
Syntexis libocedrii was in 1915 by the American entomologists discovered Sievert Allen Rohwer and initially to stem sawflies assigned (Cephidae). The British entomologist Robert Bernard Benson established the new family Syntexidae for the species. Later, the Russian paleontologist Alexander P. Rasnitsyn realized that the Russian entomologist Andrei Vasiljevich Martynov had already established the family Anaxyelidae for this species, which is only known to be fossilized.
The fossil material is divided into four subfamilies:
- Syntexinae (including the recent species)
- Anaxyelinae
- Dolichostigmatinae
- Kempendajinae
A total of eleven genera and 24 fossil species have been described. Finds are mainly from the late Jurassic and early Cretaceous .
There is still no agreement on the position of the Anaxyelidae in the hymenoptera system. Usually they are taken together with the wood wasps (Siricidae) in a superfamily Siricoidea .
supporting documents
- Wolfgang Schedl : Hymenoptera, subordination Symphyta: plant wasps, manual of zoology: Arthropoda: Insecta. Volume 4. Verlag Walter de Gruyter, 1991, ISBN 3110127393 .
- Haichun Zhang & AP Rasnitsyn (2006): Two new anaxyelid sawflies (Insecta, Hymenoptera, Siricoidea) from the Yixian Formation of western Liaoning, China. Cretaceous Research 27: 279-284.
- J. Ortega-Blanco, AP Rasnitsyn, X. Delclos (2008): First record of anaxyelid woodwasps (Hymenoptera: Anaxyelidae) in Lower Cretaceous Spanish amber. Zootaxa 1937: 39-50.
- Boyd E. Wickman (1967): Life History of the Incense-Cedar Wood Wasp, Syntexis libocedrii (Hymenoptera: Syntexidae). Annals of the Entomological Society of America 60 (6): 1291-1295.