idw – Informationsdienst Wissenschaft

Nachrichten, Termine, Experten

Grafik: idw-Logo
Grafik: idw-Logo

idw - Informationsdienst
Wissenschaft

Science Video Project
idw-Abo

idw-News App:

AppStore

Google Play Store



Instanz:
Teilen: 
29.04.2016 13:18

Trauma in a Bee

Dr. Ute Schönfelder Stabsstelle Kommunikation/Pressestelle
Friedrich-Schiller-Universität Jena

    Twisted-winged parasites of the species Stylops ovinae reproduce using so-called traumatic insemination. Entomologists of the Friedrich Schiller University Jena and the Christian Albrechts University of Kiel published on this phenomenon in the new edition of the science magazine ‘Scientific Reports‘. To inseminate the eggs, the males injure the endoparasitic females with their hook-shaped penis and inject the seminal fluid directly into their body cavity

    With the arrival of spring many insects leave their winter quarters. Presently swarms of the mining bee (Andrena vaga) emerge along sandy river valleys. These whitish-grey haired wild bees live in galleries and cavities in the ground. They feed on nectar and pollen mostly collected from willow trees. “Sometimes the first bees come out very early, weeks before it would actually be their time,“ says PD Dr Hans Pohl of the Friedrich Schiller University Jena (Germany). This usually indicates that the insects are infested by specific parasites, explains the entomologist. The native twisted-winged parasites (Strepsiptera) use the wild bees as ‘incubators‘ for their own offspring – in a quite ruthless manner. Hans Pohl and his scientific collaborators from Jena and Kiel describe the bizarre mating act of the strepsipteran species Stylops ovinae in the newly published online edition of the ‘Scientific Reports‘ (DOI: 10.1038/srep25052). It is the first time that this process has been described and examined in detail by scientists.

    The females of these insects, measuring only a few millimetres, live as parasites in the abdomen of the mining bee. Almost their entire body is hidden inside of the host, with only the pinhead-sized sclerotized fore body protruding from the bee’s body wall. “To inseminate the female, the twisted-winged parasite attaches to the bee’s abdomen and pushes its hook-shaped penis into the females neck region,“ as Miriam Peinert explains the brutal procedure. “After this the sperm fertilize many thousand egg cells in the body cavity of the female which then develop into extremely small larvae.“ The MSc candidate of the Entomology Group at the Phyletic Museum Jena is the first author of the study, which was the topic of her bachelor thesis at Jena University.

    Some weeks after that the larvae leave the female which does not survive the birth. The “mother” is virtually eaten alive, providing her body as an investment in her offspring. Generally the adults of the twisted-winged parasites serve only one purpose: to reproduce – and in the case of the males as fast as possible. They are free living, very active, with excellent flying abilities, and they live only for few hours. Within this very limited life span they have to find a female and mate. Surprisingly, once the contact is established, Stylops ovinae couples invest an unusually protracted time span with the act. It lasts up to 30 minutes, probably to reduce the sperm competition with other males.

    In their new study the Jena entomologists have analyzed the mating act for the first time using high resolution scanning electron microscopy and micro- computed tomography. As pointed out by Dr Pohl “the detail images show clearly that we are dealing with a traumatic insemination directly into the body cavity“. Until now it was assumed that the fertilization takes place via the birth canal – without any injury. The new interpretation is also clearly confirmed by histological sections of high quality. A specialized invagination or fertilizing pocket with a modified integument was identified on the fore body of the female, where the males inject the semen. This probably reduces the cost of traumatic insemination for the female, as it was also observed in the ectoparasitic bedbugs.

    Original Publication:
    Miriam Peinert et al. Traumatic insemination and female counter-adaptation in Strepsiptera (Insecta). Scientific Reports (2016), DOI: 10.1038/srep25052 http://www.nature.com/articles/srep25052

    Contact:
    PD Dr Hans Pohl, Miriam Peinert
    Institute of Systematic Zoology and Evolutionary Biology with Phyletic Museum
    Friedrich Schiller University Jena
    Erbertstr. 1, 07743 Jena
    Germany
    Phone: ++49 3641 949156
    Email: hans.pohl[at]uni-jena.de


    Weitere Informationen:

    http://www.uni-jena.de


    Bilder

    Two males of the twisted-winged parasite Stylops ovinae compete for one female hidden in the abdomen of a mining bee.
    Two males of the twisted-winged parasite Stylops ovinae compete for one female hidden in the abdomen ...
    Photo: Wolfgang Rutkies (Osnabrück)
    None

    Biologist Miriam Peinert is the first author of the current study in ‘Scientific Reports‘, which was the topic of her bachelor thesis at the University Jena.
    Biologist Miriam Peinert is the first author of the current study in ‘Scientific Reports‘, which was ...
    Photo: Jan-Peter Kasper/FSU
    None


    Merkmale dieser Pressemitteilung:
    Journalisten, Wissenschaftler
    Biologie
    überregional
    Forschungsergebnisse, Wissenschaftliche Publikationen
    Englisch


     

    Hilfe

    Die Suche / Erweiterte Suche im idw-Archiv
    Verknüpfungen

    Sie können Suchbegriffe mit und, oder und / oder nicht verknüpfen, z. B. Philo nicht logie.

    Klammern

    Verknüpfungen können Sie mit Klammern voneinander trennen, z. B. (Philo nicht logie) oder (Psycho und logie).

    Wortgruppen

    Zusammenhängende Worte werden als Wortgruppe gesucht, wenn Sie sie in Anführungsstriche setzen, z. B. „Bundesrepublik Deutschland“.

    Auswahlkriterien

    Die Erweiterte Suche können Sie auch nutzen, ohne Suchbegriffe einzugeben. Sie orientiert sich dann an den Kriterien, die Sie ausgewählt haben (z. B. nach dem Land oder dem Sachgebiet).

    Haben Sie in einer Kategorie kein Kriterium ausgewählt, wird die gesamte Kategorie durchsucht (z.B. alle Sachgebiete oder alle Länder).