California Darner
Rhionaeschna californica
This record describes Rhionaeschna californica (species). Recorded family: Aeshnidae. Recorded order: Odonata.
Identification and Appearance
Wikipedia reference for Rhionaeschna californica: http://en.wikipedia.org/wiki/Rhionaeschna_californica.
Classification
About Dragonflies and Damselflies: the wider group
Order-level background for Odonata, the group containing Rhionaeschna californica. Species-specific details appear above.
Group overview
Odonata includes ~6,000 described species of dragonflies and damselflies. Dragonflies are among the fastest flying insects, reaching 36 mph (58 km/h). They can fly in any direction including backward, and hover in place - each wing operates independently.
Ecological role of the group
Dragonflies predate dinosaurs by nearly 100 million years - fossils date to 325 million years ago. The largest dragonfly ancestor, Meganeuropsis permiana (285 mya), had a 75cm wingspan, enabled by atmospheric oxygen levels of 31-35% compared to today's 21%. Dragonflies have a 95% hunting success rate - the highest of any predator.
Economic and practical significance of the group
Dragonflies are voracious predators that consume hundreds of mosquitoes daily, providing natural pest control worth millions in reduced mosquito-borne disease risk. A single dragonfly can eat 30 to hundreds of mosquitoes per day.
Recorded sources for this group: Natural History Museum London, Britannica, fossil record research. Imported estimates may describe particular regions or reporting periods.
Photos of California Darner (2)
Photo credits: Contributed by Tony; Additional contributions by Robin McLeod , Hartmut Wisch