Szabina’s projects

My name is Szabina Schwéger, and I am a PhD student in Hungary at the University of Szeged, Department of Ecology. I successfully applied for a Campus Hungary grant which helps Hungarian PhD students spend time abroad and I will continue my research at the Frost Entomological Museum from September 2014 to February 2015. I am very excited and happy at the same time to be able to work with the Frost Museum team. So I came from a “galaxy” far, far away, and  most of the things are new and unique for me in the United States.

hovertext

1. My first fieldwork on campus and my first “prey” (inquiline gall wasp specimen). Photo by Szabina Schweger (CC BY 2.0).

My interest in ecology, morphology and the evolutionary biology of insects started seven years ago, and I have worked with the topic ever since. I graduated in 2012 from the University of Szeged majoring in Evolution and Conservational Biology. During my school years I have studied zoology, ecology, evolutionary biology, molecular biology, and phylogenetics. At that time I was really obsessed with spiders, that is why I choose to study spider community ecology and behavioral ecology, predation activity. The title of my master thesis was „The effect of winter climate on spider activity”. I mostly worked with linyphiid spiders, but I also have gained some experience in the identification of Theridiidae, Lycosidae, Gnaphosidae, Philodromidae, Thomisidae, and Liocranidae families.

After I defended my Master thesis, my interest turned towards the phylogeny of Hymenoptera. I have been a PhD candidate at the Biological Research Center, Molecular Biodiversity Group of the Hungarian Academy of Sciences since 2011. During this period I became familiar with standard molecular methods (DNA extraction, PCR), statistics (PAST, R, SPSS) and population genetic softwares (GAP, Muscle, Clustal). My research focuses on the investigation of genetic diversity, phylogeography and phylogenetic relationships of inquiline gall wasps. Gall communities have been the subject of numerous studies of community structure and evolution. The inquilinism is an obligatory relationship between two species in which the benefits are entirely unilateral but without disadvantageous effects on partner. The inquiline cynipids are specialised herbivors, who lost the capacity to induce their own galls. They are able to modify the host plant tissues which they feed on, but dependent on true gall inducers to initiate gall formation. We are interested in the Synergus genus within the Synergus complex of genera, because it is the monophyletic group, but the connections are undetermined between the distinct lineages within this group.

My main project at the Frost is the comparative study of the venom glands of the sexual and agamic forms of the gall inducing cynipid wasp, Acraspis erinacei (Hymenoptera: Cynipidae). I focus on this species because the agamic females lay eggs on buds between October and December.  The heterogony or the alteration of the asexual and sexual generations is the main cycle model within Cynipidae. Galls of the asexual generations are normally the strongest ones and they appear in during summer or early fall, while galls of the sexual generation are weak and can be found in spring or early summer. For instance the sexual and agamic generations of  Acraspis erinacei have cardinally different morphology and we aim to understand if this is related to the differences in their venom. As a first step I have collected some agamic galls, which called hedgehog gall because it has many spikes and looks like a hedgehog. Collection of female wasps will be followed by the morphological and transcriptomic characterization of their venom glands.

hovertext

2. Acraspis erinacei asexual gall and my gall collection. Photo by Szabina Schweger (CC BY 2.0).

My second project centers around a really interesting portion of the rather complex courtship behaviour of two Nasonia species (Hymenoptera: Pteromalidae). During courtship males nod their heads touching the female antennae with the base of their mandibles. Some behavioral studies from the 1970’s show that this nodding behavior increases the sexual desire of females. Although the current hypothesis is that the male wasp extract a pheromone of aphrodisiac effect with mandibular gland, the mandibular gland of Nasonia species has never been properly characterized.  During this project we aim to describe the functional morphology and to reveal the chemical composition of the mandibular gland in different Nasonia species. As the first step, I dissected and compared the head and mandible morphology of female and male specimens of Nasonia vitripennis and Nasonia giraulti  and try to establish laboratory colonies of both species using both wasp and host specimens provided by the Werren lab (http://www.werrenlab.org/).

hovertext

3. Nasonia vitripennis and Nasonia giraulti male head, Nasonia giraulti has a big “cheek”. Photo by Szabina Schweger (CC BY 2.0)

hovertext

4. Nasonia vitripennis and Nasonia giraulti female head. Photo by Szabina Schweger (CC BY 2.0).

hovertext

5. Nasonia vitripennis and Nasonia giraulti male mandible. Nasonia giraulti has a “sac-like” formation on mandible. Photo by Szabina Schweger (CC BY 2.0).

hovertext

6. Mandible of female Nasonia vitripennis and Nasonia giraulti are mostly same. Photo by Szabina Schweger (CC BY 2.0).

Nasonia parasitize are usually blowflies and fleshflies, making Nasonia an useful tool for biocontrol of these pest flies. The maintenance of Nasonia species can be easy, it does not take too much effort to work with wasps. The female lay her 20 to 40 small eggs inside the fly puparium and 36 hours after the larvae start to eat in the host fly. The pupa appears in 7 days. The wasps species are obvious to sexed in pupal stage. The Nasonia species have a short generation time (2 weeks) and large family size, therefore they are not only the perfect creatures for genetic and morphology studies but also excellent incects for the behavioral ecology as well.

Tinkering around with such small wasps is fun but challenging at times (Thanks a lot Kyle! :D).

hovertext

Szep napot! 🙂 (Have a good day!)

 

 

This entry was posted in news, research. Bookmark the permalink.

One Response to Szabina’s projects

  1. Michael Avishai says:

    Dear Dr. Schweger,
    I am a botanist but I am also interested in the ecology of a special group of oaks that are known explicedly: Gall oaks.
    I have studied in herbaria in Portugal and in plant communities in Israel and in our Jerusalem Botanical Garden galls.
    Would you be interested in collaboration? I am especially interested in the evolution of this type of parasitism and a relatively novel group of oaks.

Leave a Reply

Your email address will not be published. Required fields are marked *