Comparison of Biting Midges of the Early Eocene Cambay Amber (India) and Late Eocene European Ambers Supports the Independent Origin of European Ambers

Abstract

Of the three genera of Ceratopogoninae dominant in Late Eocene ambers of Europe, the two known are absent in the Early Eocene Cambay amber (India): The Holarctic genus Ceratopogon and the worldwide distributed genus Culicoides, known since the Late Cretaceous. Tropical biting midge genera (Meunierohelea and Leptoconops and genera with feminized male antennae: Camptopterohelea, Eohelea, and Gedanohelea) are abundantly represented in Cambay amber. The proportion of Ceratopogonini with feminized male antennae among all Ceratopogonidae dramatically increases from north to south: From 1.4-2.4 % in unbiased collections of Bitterfeld amber (Humboldt Museum collection) and Baltic amber (the Giecewicz collection) to 7 % in Danish amber and 12.7 % in Rovno amber; their proportion in Cambay amber is 17 %. The proportion of tropical specimens among specimens Ceratopogoninae in unbiased collections is 6.4 % in Baltic amber, 5.3 % in Bitterfeld amber, 21 % in Rovno and Danish amber, and 58 % in Cambay amber. Strong differences in the proportion of tropical components among Ceratopogoninae from different European ambers are in agreement with data on Cambay amber and so are indicative of origin of the European ambers under different climatic and hence geographic environments.