Dragonflies and Damselflies (Odonata)
Dragonflies and damselflies (known collectively as Odonata —meaning ‘toothed jaws’) are two distinct groups of key wetland insects you could find just about anywhere on the Weald Moors in spring, summer and autumn. What we see, however, is merely the final stage of a life spent mostly underwater in the area’s streams, ditches and ponds…
ID: Although they are referred to collectively as one order of insect, dragonflies and damselflies have many physical contrasts that not only make them easy to distinguish but also influence the locations in which you might see them. Damselflies are smaller and more delicate in appearance than dragonflies, and much less powerful flyers — meaning they generally stay much closer to the rivers, streams and ditches that form their principal habitats. While dragonflies also have a natural affinity with water, they roam more widely and can spend whole weeks away from the lakes and ponds that many species are most readily associated with.
What both groups of insects do share, however, is a love of direct sunlight, in which they can regularly be found basking on marginal bankside foliage and open bare ground. Such situations present an ideal opportunity to observe a key difference between the two because, at rest, damselflies hold their wings shut, while a dragonfly’s always remain open. A voracious predator that relies on sight to catch its insect prey, you might also notice just how large the eyes of a dragonfly are, occupying most of the head and regularly touching in the middle. By contrast, those of damselflies are very distinctly placed on either side of the cranium, giving a much more definitive impression of being two separate entities.
A Life of Two Halves: Dragonflies and damselflies spend the vast majority of their existence underwater living as aquatic larvae. In this nascent state, which generally lasts for up to two years, they hone the voracious appetite they enjoy as adults to perfection (on the wing, dragonflies must consume around a fifth of their bodyweights daily), cultivating a reputation as a fearsome ambush predator of just about any creature smaller than themselves! Before reaching adulthood, they undergo a series of moults, eventually crawling out of the water and onto a plant stem to shed their skins (known as exuvia) and assume a more familiar form. At this point, the brilliant colours exhibited by so many species are not immediately apparent, developing gradually as they approach sexual maturity. For damselflies, life as a flying adult may last as little as two weeks but dragonflies can survive for a couple of months. Breeding takes place on the wing, and the sight of amorous male odonata grabbing passing females with their claspers is a common feature of any waterside walk in late summer and autumn. Dragonflies and Damselflies lay their eggs in a number of locations (from within the water itself to bankside foliage and dead wood) and this is another spectacle to pay close attention to later in the season.
In the Field: With a vast complex of strines and ditches, the Weald Moors landscape contains plenty of potential habitat for damselflies. Among the most common is the stunning Banded Demoiselle (Calopteryx splendens), which is one of only two species to have obviously coloured wings — those of the female appear pale green, while the male exhibits a dark blue, centrally located band from which the insect takes its name. While its close relative the Beautiful Demoiselle (Calopteryx virgo) has also been recorded in the moorlands, its preference for fast flowing watercourses makes it far less common than its banded cousin, which thrives in the type of slow moving streams found on the moors.
By contrast, lakes and ponds are in much shorter supply on the Weald Moors and the list of dragonfly species recorded in the area is disappointingly slight. However, where stretches of open water do exist, and especially those with bare earthen banks, keep an eye out for a basking Black-tailed Skimmer (Orthetrum cancellatum). Mature males have a flattened-looking dusky blue ‘pruinescent’ abdomen (a visual phenomenon created by wax particles that obscure the insect’s underlying colouration and give it a dusty appearance), while females and immature males sport black vertical stripes along the length of their predominantly yellow bodies (serving as a deterrent to any potential predators). As its name might suggest, this characterful dragonfly has a habit of skimming fast and low just above the water, which can aid identification. Indeed, this close connection may also be seen during egg-laying, when hovering females actually dip their abdomens beneath the waterline to deposit their precious cargo onto the submerged vegetation below.
On the Weald Moors: While you could enjoy a brief encounter with a dragonfly or damselfly just about anywhere on the Weald Moors, a green thoroughfare like Kynnersley Drive, with its shadow network of ditches, strines, reservoirs and ponds, is undoubtedly a good place to start searching for them. Many of the odonata recorded on the moorlands have been spotted along the course of the River Strine and its tributaries, and waterside locations such as Wall Farm (which is certainly a good spot to find Banded Demoiselles), Crudgington Green and Buttery Farm have proved fertile grounds in the past.
More generally, the sight of a Yellow Wagtail or a Hobby could also provide an indication that dragonflies and damselflies are in the area, as both birds are avid hunters of odonata. Due to their sensitivity to water pollution, dragonflies and damselflies are excellent indicators of water quality, and the relative dearth of species to be found on the moors may well tell its own story. The artificial fluctuations in water levels caused by drainage and the modification of watercourses are not generally helpful to these insects, particularly during the larval stage, and are but two of many problems widely recognised as affecting dragonflies and damselflies in our countryside.