Observations of Dragonflies Visiting Lights at Night
Dragonflies (order Odonata, suborder Anisoptera) and normally diurnal. However some dragonflies are active by night. This is particularly true of long distance migrants that travel over open water where they cannot roost so must continue to fly even after dark (Corbet 1984; Hong-Qiang et al 2006). Some species of non-migratory dragonflies are also occasionally observed moving at night. Almost all of these cases are observations of dragonflies coming to lights (Corbet 1999). Reports of nocturnal adult dragonfly activity appear to be relatively scarce, especially with regard to North American species.
Since April 10, 2010 I have recorded 16 instances (7 species) of dragonflies attending black, mercury vapor and incandescent porch lights at QUBS Point. Here is a summary of those observations. Note that the times given below refer to the time when the dragonfly was discovered at the light and not necessarily when it first arrived there.
Canada darner (Aeshna canadensis); 4 records; all at combination black light/mercury vapor; time: 23:00 and 2:45
Black-tipped darner (Aeshna tuberculifera); 1 record; combination black light/mercury vapor; time: 2:45
Dusky clubtail (Gomphus spicatus); 1 record; combination black light/mercury vapor; time: 4:00
Prince baskettail (Epitheca princeps); 6 records; all at combination black light/mercury vapor; time: between 1:00 and 4:00
Common baskettail (Epitheca cynosura); 3 records; 2 at combination black light/mercury vapor, 1 incandescent porch light; time: 4:00 for all
American emerald (Dorocordulia shurtleffi); 1 record; incandescent porch light; time: 4:00
Yellow-legged Meadowhawk (Sympetrum vicinum); 1 record; at black light; time: 12:30.
In addition I have recorded one other species from a different location:
Common green darner (Anax junius) – non-migratory population; 1 record; perched on screen door in morning; Kingston, ON.
Most dragonflies that come to lights are from the families Aeshnidae (darners), Gomphidae (clubtails) and Libellulidae (skimmers) (Corbet 1999). My species list includes representatives from each of these families plus three species of Corduliidae (emeralds and baskettails). With regard to nocturnal movement, I was unable to find species-specific references for most of the dragonflies on the list except for prince baskettail. Both sexes of prince baskettail have been observed perching at street lights between 23:00 and 1:30, staying for about 20 min then departing (Young 1967).
Dragonflies often emerge from their larval exoskeletons after dark, so nocturnal activity among teneral dragonflies might be expected. There are some instances of teneral dragonflies coming to lights during their maiden flights (Corbet 1999). None of the dragonflies collected at QUBS lights in 2010 have been teneral however. Why fully adult dragonflies appear at lights after dark is unknown. It may be that they are disturbed form a nearby roost and fly toward a light because that is all they can see in the dark (Pinhey 1976 in Corbet 1999). It seems unlikely that they are foraging around lights because no active hunting behaviour has been observed.
I will continue to keep records of dragonflies attending lights and make occasional updates to the above list as comments to this post. Thanks to Line Faber and Georgia Lloyd-Smith for collecting dragonflies at the lights.
Corbet, P.S. 1984. Orientation and reproductive condition of migrating dragonflies (Anisoptera). Odonatalogica 13: 81-88.
Corbet, P.S. 1999. Dragonflies: behaviour and ecology of Odonata. Cornell University Press. Ithaca, NY.
Hong-Qiang, F., Kon
Posted by Mark Andrew Conboy