Ectoparasitic Water Mites on Blue Dasher

Subject: Blue Dasher with — eggs?
Location: NH, USA
July 20, 2013 9:01 pm
Dragonfly (I think it’s a Blue Dasher). I’m wondering what the little red spheroids are. Are they insect eggs? Was it parasitized by something?
Signature: Joel Stave

Water Mite Larvae on Dragonfly
Water Mite Larvae on Blue Dasher

Dear Joel,
Dragonflies are frequently hosts to Ectoparasitic Water Mite larvae that attach themselves to the Dragonfly while it is still an aquatic naiad.  The Northwest Dragonflier website maintains that when the naiad molts into a winged adult, the larval Water Mites in the genus
Arrenurus crawl from the cast off exuvia onto the still soft body of the winged adult and attach themselves as ectoparasites.  They derive both nourishment from this and the advantage of transportation to a new body of water where they can drop off and mature.  Light infestations do not negatively impact the Dragonfly much, but heavy infestations can be very detrimental to the adult Dragonfly.  Here is another simple explanation on Taos Telecommunity.  We believe you are correct that this is a Blue Dasher, Pachydiplax longipennis, based on photos posted to BugGuide

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