The obligate fig-pollinator family Agaonidae in Germany (Hymenoptera, Chalcidoidea)

Abstract

All native and many cultivated fig plants are pollinated by representatives of the family Agaonidae (fig wasps), which are specialised, secondarily phytophagous relatives of parasitoid wasps that evolved an obligate mutualism with fig trees. So far, distribution of Agaonidae in Europe has been limited to southern, mostly Mediterranean areas, for example, in Greece, Croatia, Hungary, Italy, France, Spain and Portugal. Here, we report the first four records of the family for Germany, all in the form of the widespread species Blastophaga psenes (Linnaeus, 1758). New verified records are from three States in western and south-western Germany, Baden-Wuerttemberg (Radolfzell at Lake Constance and Sasbach am Kaiserstuhl near Freiburg), Saarland (Saarbrücken) and Northrhine-Westalia (Bochum) and all are based on citizen-scientist observations and collections. The new records are considerably more northern than previously recorded localities and, strikingly, geographically distant from these. All records can be attributed to the presence of large male caprifig trees (Ficus carica L. var. caprificus), whose three generations of fruits host the development stages of Blastophaga psenes. We generated DNA barcode data of specimens from three localities and added them to the national GBOL (German Barcode of Life) database and the international Barcode of Life database (BOLD). The somewhat surprising occurrence of the species/family in Germany might be attributable to increasing temperatures as a result of global warming, but this needs further investigation. Additionally, the presence of fig wasps, assuming it stabilises, could offer new opportunities for fig farming in Germany.