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“A damsel worth thinking about.”
Classification:
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Odonata
Suborder: Zygoptera
Families: hemiphlebioidea, Coenagrionidae, Lestoidea, Calopterygoidea
Description:
Often considered to be dragonflies, damselflies show similar characteristics to that of their closely related relatives. They are seen to have a toothpick or fragile like bodies with brightly colored, often neon, patterns to attract future mates for breeding; whereas the dragonfly is much larger in size and may show less visually stunning colors. Differences between the two suborders of Odonata can be seen when they are at rest. When at rest, the damselfly will showcase its wings in folded upwards position along its body while the dragonfly displays its wings, spread out in a horizontal fashion. An additional feature to look for is the placement of the eyes on both the damselflies and dragonflies; whereas damselflies tend to have them spread apart across the head, instead of close together or touching as in the dragonflies.
During the larval stage damselflies are often known as nymphs and live in shallow fresh water systems were they spend the first half of their lives under water, until they are ready to undergo metamorphosis. The nymphs display three large external gills at the end of their abdomen, allowing them to breathe and to be easily in their aquatic environment. In an addition to this, theses three large gills also aids in their identification as a larval stage of the zygoptera suborder.
Their feeding habits of consuming and attacking other animals of pray, strongly suggest that they are predators relying on same size or smaller animals or insects as a food source. In some cases they may go after larger animals such as a small humming birds or crane fly larvae in order to satisfy their appetite. Though they are generally open to any pray that may come their way: there are a few species, such as Pseudostigmatidae, that pray on a particular food source such as spiders in which they are willing to off them off their webs. However it is important to note that the adults generally only feed while in flight and though they are predatory creatures they are not at the top of the food chain.
Phylogeny and Taxonomy
Distribution
Damselflies are found in all continents except Antarctica, they require fresh water and terrestrial systems in order to thrive. They generally do not migrate far from where they are born with the exception of a few species that can fly high enough to catch the stronger wind currents. In addition to their habitat needs, a wide range of micro habitat is needed for reproduction so that there is cover for the nymphs to hide and hunt in. Due to such high quality micro habitat needs it is presumed that the damselfly can act as a good biological indicator of the stream/habitat ecological health.
Anatomy
The basic body parts that make up the zygoptera anatomy are the head, compound eyes, thorax, abdomen, and its legs. These body features are found in both adult and larval stage but ends there, between both larval and adult stages there are distinct characteristics that are unique to that stage in life. In the Nymph stage there are only two differences that are outstanding to that of the adult stage. With the first being its large hinged jaw that is used to attack and capture pray. This lower jaw lays compressed up against the body and is a spoon like appendage that can be thrust forward via muscle contractions. This organ is said to be one of the most effective system of pray capture as the spoon like appendage is covered in hook like bristles that can hold onto the pray as it extends outwards of as much as six times the width of its head. The secondary feature of the nymph stage is the external gill located at the end of the abdomen in the form of three bladed structures. Due to the the external gills, any sediment that can be kicked up in the stream bed can cover the gills and thus suffocate the animal. There for Damselfly nymphs prefer a rocky substrates which can show an additional sign for good stream health.
As an adult the head of the damselfly has developed special and unique features to help aid them in their survival. Setting aside the large complex eyes that can easily be seen from a distance, the damselfly contains three more additional eyes found on top of the head between the two large complex eyes. These are known as ocelli, the ocelli are simple eyes that cannot make out images but are well adapted to sensing different lighting conditions and are able to react to situations quicker than that of the compound eye. Because of this, it is thought that the ocelli are helpful during flight as additional stabilizers for when they move around and rapidly change different directions. Additional unique feature found on top of the head is the frons, which is also located between the complex eyes and next to the antennas; they are used to help indicate wind direction and speed.
The next and most obvious appendages are the wings, which there are two pairs attached to the pterothorax. The two pairs of wings are subdivided into two categories know as the forewing (the pair closes to the head) and the hindwing (the pair furthest away from the head). Each individual wing of a damselfly is controlled independently allowing it to
hover, fly backwards and even alternates the rates at which each wing beats, if any at all, for courtship display rituals. Pterothorax is one of two fused sections that make up the overall thorax and is often the site where the wings and legs are located. Prothrorax is the second segment of the overall thorax and is where the head attached to the body. Following the thorax is the abdomen that displays the long needle like body which gives damselflies their name, due to the fact that they look delicate. Each abdomen of various species consist of ten abdomen sections, in which on the tenth section a set of claspers (in males) or a set of ovipositor (in females) that can be found. The claspers are used during mating allowing two damselflies of opposite sex to attach themselves to each other by holding onto the females prothorax while the female will insert her ovipositor into the male.
Reproduction
During breeding the Male damselfly well display a courtship of various areal acrobats in order to attract a female partner.
If all goes well and the female chooses to mate with the male, the two couples well enter into a wheel position by having the female attaching to the male, behind the thorax, while he is still attached. When this is done the female has inserted her ovipositor into the male in order to receive his sperm. The ovipositor is an organ located at the end of the abdomen of the female damselflies. After insemination has occurred, the sperm may be stored for up to a week or two before being used to fertilize the eggs. After the male has inseminated the female he may leave and move on with his life. However often times he will continue to stay attached to his mate until she deposits the egg for fear that another male may move in and replace his sperm with their own; as the female will only use the latest sperm packet. This is done so by showing how strong and compatible he is for matting, by hovering in place for long periods of time: flexing and twisting its abdomen and or even hoven in one spot while one pair of wings quits beating. If the female is interested in the male, the male will attach himself to the female by using the clasp at the end of its abdomen and attaching it behind the females head onto the protrorax, which is known as coupling. If the female chooses not to pair with the male, then often times they well flee with intense areal acrobatic maneuvers as they try to escape the male. These one going dogfights can be lethal as the make fly will often attack the female or break up other pairs in order to have his way with a suitable mate to his liking.
Once the eggs are fertilized the female will make an insertion into a stock of a plant that’s in or near water and insert her eggs into the stock where they will be protected from predators as they overwinter. Once the newly developed nymphs hatch, during the early spring, they will have a few days of nutrition stored in their gut as a form of yoke. After this is consumed they will need to hunt for their own pray. Over the course of the life time nymphs will undergo a dozen or so molting’s be for emerging as a fully grown adult. This process is said that it can take anywhere from a summer season to as many as four years depending on the amount of nutrients available.
Interesting fact
Over the year’s scientist have used damselflies and dragonflies alike as bio-indicators for determining the health of various ecosystems. Due to the various needs, of different species, and their ability to be highly intolerant of pollution damselflies can resemble good stream quality simply by being present or not.
Work Cited
Chew, Peter. "Dragonflies mating and reproduction". Brisbane Insects. Available from http://www.brisbaneinsects.com/brisbane_insects/Mating.htm. Internet; accessed Nov. 30
2015.Vince. Introduction to the Odonata. Berkeley : Berkeley university , Not Applicable . http://www.ucmp.berkeley.edu/arthropoda/uniramia/odonatoida.html
Britannica. "Damselfly". Encyclopedia Britannica . Available from http://www.britannica.com/animal/damselfly. Internet; accessed Nov. 30 2015.https://danielandmattp.wikispaces.com/Basic+Anatomy
Sail pathfinders . "Odonates (Damselflies and Dragonflies)". Sail Pathfinders . Available from http://www.austinsouthpathfinders.com/odonates-damselflies-and-dragonflies.html. Internet; accessed Nov. 29 2015.
Venable, Norma. Drragonflies. Morgantown : West Virginia University, Not Applicable . http://anr.ext.wvu.edu/r/download/48166
Enallagma . "Damselfly mating ". Enallagma. Available from http://www.enallagma.com/cerci/damselflyMating.html. Internet; accessed Nov. 29 2015.
Ackerman, Jennifer. "Dragonflies strange love". National Geographic . Available from http://ngm.nationalgeographic.com/print/2006/04/dragonfly-mating/ackerman-text. Internet; accessed Dec. 1 2015.
Brook S. McDonald, Gary W. Mullins, and Stuart Lewis. 1991. “Macroinvertebrates as Indicators of Stream Health”. The American Biology Teacher 53 (8). University of California Press: 462–66. doi:10.2307/4449370.
Subramanian. K. A.. " ODONATAAS INDICATORS OF RIPARIAN ECOSYSTEM HEALTH A CASE STUDY FROM SOUTH WESTERN KARNATAKA, INDIA ". Fraseria . Not Given. (2008 ), 83-95. http://www.ces.iisc.ernet.in/biodiversity/pubs/ces_pubs/pubs_2009/theme1_17.pdf. (accessed Dec. 1 2015 ).
Katatrepsis. "Dragonflies vs damselflies". Katatrepsis. Available from http://katatrepsis.com/2011/08/14/dragonflies-vs-damselflies/. Internet; accessed Dec. 2 2015.
This Page was created by Connor Nicholas for the intent of it being a final term project. All information and pictures where gathered from the above sited sources unless stated else where. Page creation date: 12/01/15
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