Length 50-62 mm, large for a damselfly.
A very large spreadwing with bold stripe on thorax.
The bright yellow stripe is the easiest fieldmark to see at a distance; it occurs on both males and females. Males are nearly always darker in color than females; females when laying eggs may appear putty-colored (much the same color as the withered leaves in which they lay eggs.) The eyes of males are bright lapis blue. The eyes of females are paler blue.
Western and southern North America. (More common in western United States than in the east.) Also central America and northern South America. This species recently (1920's and later) expanded its range in North America to the east and north.
Small ponds, streams.
This species breeds readily in heavily vegetated water gardens with unpolluted water, as well as in natural water. Females oviposit in vegetation such as water iris while clasped by male. Males perch "hanging" from such vegetation either over or near water, usually fairly low (under 2 feet.) Occasionally the nymphs can be spotted in winter, basking in sunwarmed shallow water alongside tadpoles...recognizable by their "Y" "tails" (actually, gills.)
Although Great Spreadwings are usually found close to water, we have also found them in a small woods on a seasonal stream, even when the stream had recently dried up.
Summer into early fall.
Timing varies with temperature; these insects may show up in April in central Texas (and presumably other southern locations) and remain active until late fall (which here is November.)
During mating, and after collection of sperm, the female cuts a slit in emergent vegetation and oviposits in it. Nymphs then develop underwater until they climb out, ready to emerge as adults. As with other Odonates, emergence usually occurs under cover of darkness.
Great Spreadwings are relatively easy to photograph, as they will hold still for longer than many Odonate species, and when startled often return to the same perch or one nearby.
Great Spreadwings are substantially larger than other spreadwings, and are the only spreadwings with the broad yellow "racing stripe" on the side of the thorax.
Giff Beaton's page
has a photograph of A. grandis.
Odonata Central (Texas)
--a good species account