Fig wasps

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Fig wasps
Female specimen of Blastophaga psenes

Female specimen of Blastophaga psenes

Systematics
Class : Insects (Insecta)
Order : Hymenoptera (Hymenoptera)
Subordination : Waist Wasps (Apocrita)
Partial order : Legimmen (Terebrantia)
Superfamily : Wood Wasps (Chalcidoidea)
Family : Fig wasps
Scientific name
Agaonidae
Walker , 1848
Sexual dimorphism in Blastophaga psenes
Pleistodontes frogatti

The fig wasps (Agaonidae) are an insect family from the superfamily of the wood wasps ( Chalcidoidea), of which around 35 species are known. They are characterized by the fact that they lay their eggs in the inflorescences of fig species and at the same time ensure that the flowers are pollinated. The fig wasps benefit from this symbiosis by protecting the eggs and larvae in the inflorescences or later the fruits and finding food. There is usually a very close relationship between fig wasp and ficus species. But there are also many self-fertilizing fig varieties .

Pollination of the common fig

The common fig ( Ficus carica ), the fruits of which are sold fresh and dried as figs, is visited by the only European species, Blastophaga psenes . The real fig, however, only produces long-handled , fertile female flowers, which is why the buck fig is necessary for its pollination . It has both short-handled, sterile female (gall flowers) and partially male flowers near the ostiolum (distal opening narrowed by scales, bracts ). However, this is more complicated because the buck fig develops three generations of inflorescences on the same plant (Vorfeigen or Profichi, Summer fig or Fichi or Mammoni, Nachfeigen or Mamme), only with the Vorfeigen a lot of pollen is produced by the existing male flowers There are no late figs and only a few of the summer figs, because the male flowers of the summer and late figs are more or less degenerate.

The pregnant fig wasps (foundress) penetrate through the opening into the inflorescence of the buck fig, thereby losing their wings and sometimes their legs and antennae. After that, the females bore with her ovipositor (ovipositor) holes in the ovary of Gallblüten and lay their eggs after oviposition dies the female. When the eggs are laid, the flowers form galls (psenocarp) in which the larvae feed on the ovary and ovule , from which the few wingless, almost blind males hatch first. After hatching, the males drill entrances into neighboring galls in order to mate with the females there. Then they also drill holes in the pericarp to increase the oxygen content, this favors the development of the female larvae and the male flowers, then the males die. The females get out through the ovary wall and then out into the open on the way through the ostiolum and, if available, are loaded with the pollen of the male flowers (collect with a fringe of hair; Coxal Comb , store in the pollen pocket; corbicula ). They now fly to other buck figs and the real figs, which they pollinate when they are loaded with pollen, but cannot lay eggs here. It is not possible to lay eggs because the females cannot reach the ovary with the laying stinger because of the long stylus. This was overlooked in the first attempts at growing figs in California . Some of the females perish while the others go back to the buck figs to lay their eggs there. Towards the end of the year, the larvae of the next year's generation develop in the night figs, they overwinter and then hatch again in spring.

Genera

Individual evidence

  1. ^ Elsa Franke, Reinhard Lieberei, Christoph Reisdorff: Useful plants. 8th edition, Thieme, 2012, ISBN 978-3-13-530408-3 , p. 212.
  2. ↑ Abraham H. Halevy: Handbook of Flowering. Volume 6, CRC Press, 1989, ISBN 0-8493-3916-2 , p. 343.
  3. ↑ Dieter Helm: Introduction to Biology. 2nd edition, Lulu, 2010, ISBN 978-1-4461-3050-6 , pp. 131 f.
  4. ↑ VH Resh, RT Cardé: Encyclopedia of Insects. Academic Press, 2003, ISBN 978-0-08-054605-6 , p. 922.

literature

  • The modern animal lexicon. Volume 3, Bertelsmann Publishing Group, 1981, DNB 800921933 .
  • PH List, L. Hörhammer: Hager's Handbook of Pharmaceutical Practice. Volume 4: Chemicals and Drugs (CI – G). 4th edition, Springer, 1973, ISBN 978-3-642-80621-6 , p. 991.

Web links

Commons : Agaonidae  - Collection of images, videos and audio files