The Odonata Family Cordulegastridae (Spiketails) comprises large dragonflies, black or brown and marked with yellow, with large green or blue eyes that meet at a point at the middle of the head. The family is mostly Nearctic and Palaearctic in distribution. In the Americas the family reaches its greatest diversity in the southeastern part of the United States. The common name used for these insects in the USA, "spiketails", refers to the enlarged prolongation of the vulvar lamina of the females, which may project beyond the tip of the abdomen. The females oviposit alone, hovering over shallow portions of streams with their abdomens held nearly vertically, and jab their abdomens repeatedly into the substrate, thus pushing their eggs into the the stream bottom. Below is a photo of a female Cordulegaster diadema from Arizona, USA, that shows the spike-like ovipositor.
In the Old World, Asia is a center of Cordulegastridae diversity. The Oriental genus Anotogaster is found mostly in montane regions of Asia. The video footage below shows a female Anatogaster sieboldii ovipositing in a small stream. The film was made by Naoya Ishizawa at Mikajima, Tokorozawa, Japan, in August 2001. Roy Beckemeyer transferred the video to a 1.95MB mpg file. Video © 2001 by N. Ishizawa.
Corbet, P.S. 1999. Dragonflies: Behavior and Ecology of Odonata. Comstock Publishing Assoc. Cornell University Press. Ithaca, NY. [See especially p. 21-22, Plate E4, Tables A2.5 and A2.6]
Vick, G.S. 2001. Family Cordulegastridae (Goldenrings). pp. 146-148 In J. Silsby, Dragonflies of the World. Smithsonian Institution Press. Washington, D.C.