Past and present of the relict family nemonychidae (Coleoptera, Curculionoidea)

Abstract

Nemonychidae is a small family of phytophagous Coleoptera, which consists of 22 living genera and 65 known species. It constituted the dominant group amongst all Phytophaga in the fossil records of the Upper Jurassic, some 200 million years ago, and is safely regarded as the most primitive family of Curculionoidea. As 20 out of the current 22 genera are strictly confined to conifers, it is assumed that the ancestral forms were living on Gymnospermae. The adults of Nemonychidae, at least during their reproductive season, and the larvae feed in the main on pollen. The mature larvae abandon the strobili (male cones) or flowers and drop to the ground to pupate in the soil. Under the same humidity and temperature conditions, some larvae emerge as adults within 2 to 6 months whilst others undergo a diapause of 1 or 2 years. The Palearctic has 2 genera confined to Pinus (Pinaceae) and 1 to Consolida and Delphinium (Ranunculaceae); the Nearctic also has 3 genera, all on Pinus, 1 shared with the Palearctic; the Neotropic has 5 genera, 3 on Araucaria (Araucariaceae), 1 on Saxegothaea (Podocarpacea) and 1 on Nothofagus (Fagaceae), all but 1 species from Chile; the Australian Region has 5 genera, 4 on Araucaria and Agathis (Araucariaceae) and 1 on Phyllocladus, Podocarpus, Dacrycarpus and Dacrydium (Podocarpaceae).