The main research work focuses on the taxonomy, systematics and biogeography of the huntsman spiders (Sparassidae). This spider family with mainly tropical to subtropical distribution counts more than 1200 species worldwide. Moreover, various taxa of further spider families are treated and revised (u.a. Ctenidae, Araneidae, Pisauridae, Phrurolithidae etc.)
According to recent results the subfamily Heteropodinae seems to have radiated into the present genera first in Asia. Thereafter single genera split into species swarms in the mountain ranges of continental southern Asia (Pseudopoda, Sinopoda) and in the entire tropical Island Asia as well as in Australia (Heteropoda, Pandercetes). Cooperations exist with the National Science Museum Tokyo (Dr Hirotsugu Ono), the Museum of the Institute of Zoology, Chinese Academy of Sciences (Prof. Dr Shuqiang Li), and Wuhan (Prof. Dr Jie Liu).
A second focus within the Sparassidae concerns the African fauna. An identification key for African genera has been compiled. Furthermore, one subfamily in Africa as well as in Asia was being investigated concerning its phylogenetic relationships (Eusparassinae, PhD Majid Moradmand). Currently, two new genera from East Africa and Madagascar are described and revised.
Spiders of Laos
Since 2003 expeditions are conducted in Laos, Thailand, Myanmar, Malaysia, Singapore, China and Cambodia. Numerous publications on the spider fauna have been published. Cooperations exist with the National University of Laos (NUoL) and the Royal University of Phnom Penh (RUPP), and with various institutions present in Laos (WCS, WWF, UNESCO, GAPE, SODI). Since 2010 one student was supervised at the NUoL.
Spiders in amber
Studies on fossil spiders lead to a new picture of biocoenoses in former times. A cooperation with Dr. Monica Solorzano-Kraemer analyses the fauna of amber forests in the Dominican Republic, on Madagascar and in New Caledonia as well as a comparison of the recent with the ancient fauna.
Spider fauna and neozoa in Central Europe
Invaded species, so-called neozoa, can have an immense influence on the indigenous fauna and flora. Long term studies show how strong the influence is and whether present species are thus newly endangered. Distribution maps are good for recognizing and tracing trends. To get as much data as possible it is important to make the information accessible to a wide audience, e.g. through a dichotomous key or a photo gallery for recognizing species. Initial events could be shown for Holocnemus pluchei and the Trochanteriidae Zimiris doriai. Recent findings of the poisonous spider genera Latrodectus and Phoneutria in Germany were published.
Peter Jäger was a council member of the International Society of Arachnology (2004-2010) and is its correspondent for Germany, was president of the Arachnologischen Gesellschaft (AraGes, 2004-2010) as well as on the European board of trustees for the ‚Spider of the year’ (2000-2009). He is associate editor of Zootaxa and member of the editorial board of Arachnologische MItteilungen and Acta Arachnologica Sinica. Moreover he is member of the expert board of Araneae. 2012 Peter Jäger founded with colleagues from Tokyo and Beijing the Asian Society of Arachnology, he organised the founding meeting in Laos (Pakse) and visited congresses in Chiang Mai (Thailand), Amravati (India), Chongqing (China) and Bangkok (Thailand).
Jochen Martens works on, among other things, Opiliones; especially with material from his expeditions to Central Asia, the Himalaya, China and the Caucasus.
Manfred Grasshoff worked for a long time with the taxonomy of Araneidae. Here he investigated phylogenetic relationships by analysing the functional and construction morphological components of genital structures.