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Widow Skimmer Dragonfly - Libellula
luctuosa |
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Female
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These photos were taken near the west branch of the DuPage River in Illinois. The widow skimmer is famous for its pruinosity - the white, waxy coating on the dragonfly's wings and abdomen. Dragonflies have excellent eyesight. Their compound eyes have up to 30,000 facets, each of which is a separate light-sensing organ or ommatidium, arranged to give nearly a 360° field of vision. Odonates are completely harmless - they do not sting or bite. Indeed, they are beneficial in the same respect spiders and other predators are beneficial - they keep the burgeoning insect population in check. Many of these species prey on each other; I often see dragonflies with damsels in their clutches. Dragonflies are among the most ancient of living creatures. Fossil records, clearly recognizable as the ancestors of our present day odonates, go back to Carboniferous times which means that the insects were flying more than 300 million years ago, predating dinosaurs by over 100 million years and birds by some 150 million. |
Male widow skimmer with mite hitchhikers on abdominal segments
8&9 (see below)
| Much larger dragonfly species existed in the distant past than occur on
earth today. The largest, found as a fossil, is an extinct Protodonata
named Meganeura monyi from the Permian period, with a wingspan of 70-75
cm (27.5-29.5 in). This compares to 19 cm (7.5 in) for the largest
modern species of odonates, the Hawaiian endemic dragonfly, Anax
strenuus. The smallest modern species recorded is the libellulid
dragonfly, Nannophya pygmaea from east Asia with a wingspan of only 20
mm, or about ¾ of an inch. Dragonflies are the world's fastest insects and, although estimates of their speed vary wildly, most credible authorities say they are capable of reaching speeds of between 30 and 60 km/h (19 to 38 mph). A study showed that dragonflies can travel as much as 85 miles in one day. |