micah_shively's Identifications

Extra-large Spiketail dragonfly with blue eyes was patrolling back-and-forth over a small stream.

Pacific Spiketail (Cordulegaster dorsalis) is a very large Dragonfly in the Spiketails (Cordulegastridae) family that is found at small streams in wooded hillside areas. Length is 70-85mm (up to 3.4 inches) and wingspan is 86-105mm. They fly May-November. It has 2 yellow stripes on thorax sides. Eyes are blue and barely touch. Abdomen is blackish with yellow spots on S2-9.

Dragonflies (Anisoptera) of California, Kathy Biggs & Sandra von Arb, July 2024, pp. 25,152, 175-177, 178, 180. Companion website: http://bigsnest.powweb.com/southwestdragonflies/caphotos/

Dragonflies and Damselflies of the West, Princeton Field Guides, 2009, by Dennis Paulson, pp. 308-310.

BugGuide: https://bugguide.net/index.php?q=search&keys=Cordulegaster+dorsalis&edit%5Btype%5D%5Bbgimage%5D=on

Law's Field Guide to the Sierra Nevada, John Muir Laws, California Academy of Sciences, 2007, p. 213.

Field Guide to California Insects, by Kip Will, J. Gross, D. Rubinoff , J. Powell, 2nd ed., 2020
Dragonflies (Suborder Anisoptera) pp. 56-66.

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Odonata (simple) External Anatomy Diagram: https://www.vararespecies.org/image/odo-dorsal.jpg

Odonata Terminology by Dennis Paulson: https://www.pugetsound.edu/puget-sound-museum-natural-history/biodiversity-resources/insects/dragonflies/glossary

Inaturalist Projects:
Dragonflies and Damselflies of the New World: https://www.inaturalist.org/projects/dragonflies-and-damselflies-of-the-new-world
Odonata: Dragonflies and Damselflies: https://www.inaturalist.org/projects/odonata-dragonflies-and-damselflies--2
North America Odonata: https://www.inaturalist.org/projects/north-america-odonata

BugGuide: Arthropods: Photos of Insects, Spiders & Their Kin (US & Canada), clickable categories or use search bar (scientific name): https://bugguide.net/node/view/3/bgpage

Dragonflies and Damselflies are flying insects in the Order Odonata. Adults are highly aerial. Larvae are aquatic and predatory. Adult dragonflies are characterized by a pair of large, multifaceted compound eyes, two pairs of strong, transparent wings, sometimes with colored patches, and an elongated body. Dragonflies can be mistaken for the closely related Damselflies, but the wings of most dragonflies are held flat, outward at a right angle, away from the body, while damselflies hold their wings folded at rest, above, or parallel to the abdomen. Dragonflies are agile fliers, while damselflies have a weaker, fluttery flight.
Odonata pairs oviposit in tandem. They are joined together while laying eggs on water. When joined together, they exhibit "mate-guarding" behavior while the female lays eggs with tail-dipping motions into water. They stay fairly low between descents and often tap the water repeatedly before moving a short distance and doing it again.

Dragonflies and Damselflies of the West by Dennis Paulson, 2009, p. 459.