Abai, MR

6th International Congress of DipterologyThe search for a sister group:First results on the phylogeny, taxonomy and biogeographyof the genus Germaria (Diptera, Tachinidae)Ziegler, J.Humboldt-Universität zu Berlin, Museum für Naturkunde, Zoologie, Invalidenstrasse 43,10115 Berlin, Germany. E-mail: joachim.ziegler@museum.hu-berlin.deThe author is in the process of revising the phylogeny, taxonomy andbiogeography of the poorly-known Holarctic tachinid genus GermariaRobineau-Desvoidy, 1830. This genus currently contains 11 rarelycollected species of which 8 have been described in the last 50 years. Afurther 3-4 undescribed species have been found by the author in thecourse of his current investigations. The only species of the genus to have arelatively wide distribution are the Holarctic G. angustata and the possiblytranspalaearctic G. ruficeps. The other species are found only in thesouthern Palaearctic eremial belt. This region – the former Thetys – has aclimate that is becoming progressively more dry and has been separatefrom the rest of the Palaearctic region since the Tertiary. This region isthought to be the centre of origin of the genus Germaria. At least 6 speciesoccur in the Mediterranean subregion, and three of these are also found inparts of the adjacent Irano-Turanian subregion to the east, where, togetherwith at least eight further species that occur there, they form a centre ofdiversity.By adapting to hosts that are difficult to access, the species of Germariahave come to occupy a very special niche. Their hosts are Lepidopteralarvae that live in the soil or which are borers in plants, the familiesPhycitidae and Sesiidae. As the female flies do not have a specialisedovipositor, the first-instar larvae have to act independently to seek out theirconcealed hosts, and they have adaptations for this. On the other hand, thecharacters of the third larval instar are predominantly plesiomorphous.329