Calvert County Dragonflies and Damselflies: Part 13 – Dasher/Gliders/Amberwing/Whitetail Dragonflies of the Family Libellulidae

Family: Libellulidae (Dasher/Gliders/Amberwing/Whitetail)

Due to the large number of species present for this family, I am continuing to break down this family into smaller segments. This particular grouping is composed of a variety of dragonfly types and the common names sound strangely similar to a herd of Santa’s reindeers.

All five of the species listed below can be found in all three southern Maryland counties according to Richard Orr’s database. Currently only three species in this grouping are represented in the iNaturalist database for all three southern Maryland counties. The two species of Gliders are currently represented by only a single St. Marys County observation of a Wandering Glider.

For this group, I have made contributions for three species to the Calvert County iNaturalist database: 18 of 41 and 10 of 42 observations for Blue Dasher and Common Whitetail dragonflies, respectively and have added all eight observations for the Eastern Amberwing.

Listed below are the species within this group that have been observed in at least one of the southern Maryland counties and a comparison of the two databases is made (as of March, 2020). As was done with the previous family, I have included notes extracted from the book “Natural History of DelMarVa Dragonflies and Damselflies” by Hal White (reference 1). Of particular relevance for Calvert County, I have also included information on all five of the species of this group that were observed at the Cove Point LNG Property and reported in “2011-2012 Survey of the Dragonflies and Damseflies (Odonata) of the Cove Point LNG Property (Calvert County, Maryland” by Richard Orr (reference 2).

Blue Dasher/Pachydiplax longipennis
The Blue Dasher is our most abundant dragonfly all summer long. In July, probably more than half of all dragonflies present are this species. It appears to be expanding its range northward on both East and West Coasts. (1)
Cove Point adult abundance and flight period – abundant/19-May to 14-Oct. (2)
iNaturalist research grade observations:​ Calvert = 41 (May-Oct)​ St. Marys = 3 (Jul-Aug) Charles = 11 (May-Sept)
MD Biodiversity (i.e., Richard Orr):​ Calvert – present St. Marys – present​ Charles - present

Wandering Glider/Pantala flavescens
The Wandering Glider is the only worldwide species of dragonfly and is known from every continent except Antarctica. Ships a thousand miles at sea have encountered it. (1)
Cove Point adult abundance and flight period – common/24-May to 11-Sept. (2)
iNaturalist research grade observations:​ Calvert = 0 St. Marys = 1 (Sept) Charles = 0
MD Biodiversity (i.e., Richard Orr): ​Calvert – present St. Marys – present Charles - present

Spot-winged Glider/Pantala hymenaea
This is an opportunistic species characterized by a short life cycle and a high dispersal ability. (1)
Cove Point adult abundance and flight period – common/21-May to 22-Aug. (2)
iNaturalist research grade observations:​ Calvert = 0 St. Marys = 0​ Charles = 0
MD Biodiversity (i.e., Richard Orr):​ Calvert – present St. Marys – present Charles - present

Eastern Amberwing/Perithemis tenera
This species exhibits sexual dimorphism which is common among dragonflies and damselflies. But it also exhibits female polymorphism, the biological significance of which is unclear. (1)
Cove Point adult abundance and flight period – abundant/19-May to 03-Sept. (2)
iNaturalist research grade observations:​ Calvert = 8 (Jun-Aug) St. Marys = 2 (Jul-Sept) Charles = 3 (Jun)
MD Biodiversity (i.e., Richard Orr):​ Calvert – present St. Marys – present​ Charles - present

Common Whitetail/Plathemis lydia
The Common Whitetail is a striking example of sexual dimorphism. Males have a bright white abdomen and prominent black bands across both wings. Females have a brown abdomen and several dark patches on the wings. (1)
Cove Point adult abundance and flight period – abundant/21-Apr to 30-Sept. (2)
iNaturalist research grade observations:​ Calvert = 42 (Apr-Sept) St. Marys = 4 (Apr-Jul) Charles = 11 (Apr-Aug)
MD Biodiversity (i.e., Richard Orr):​ Calvert – present St. Marys – present​ Charles - present

Publicado por rosalie-rick rosalie-rick, 18 de marzo de 2020

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