What are Dragonflies?
Dragonflies are one of the fastest insects in the world. One of the main characteristics of these insects is the multifaceted eyes they posses, as well as they’re strong transparent wings and long bodies. They posses six legs, which is what qualifies them as insects, but do not walk well. According to Jurg de Marmels, in Venezuela, there are 480 species of Dragonflies, 113 of which are considered rare.
They are predators, since they eat other insects like mosquitoes, bees, flies, ants and sometimes butterflies; but they are also victims of the food chain, seeing as they are prone to predation by frogs, spiders, fish, water bugs, lizards and even larger Dragonflies.
Dragonflies lay eggs called “nymphs,” on floating or emerging water plants. When laying eggs, Dragonflies submerge themselves completely into the water in order to lay the eggs safely. Nymphs later hatch, in which form they will spend most of their lives; living beneath the water’s surface using their “extendable jaws” to catch their food, mostly being invertebrates like mosquito larvae, but is not limited to vertebrates as well, like fish and tadpoles. Some are able to hunt on land as well; this is due to ancient times when terrestrial predators were much clumsier. The nymph “stage can last as long as five years, when the dragonfly then emerges from the water, through a plant or reed and through contact with the air the larvae starts breathing. The skin splits at a point behind its head and it then crawls out of its larvae skin, a metamorphosis. It then continues to feed off of small insects like ants, flies and mosquitoes.
One of the most interesting characteristics of Dragonflies is their wings. They allow them to be one of the fastest insects in the world, reaching speed of up to 90km/h. These strong, transparent wings enable the insect to fly in six directions: up, down, forward, backward and from side to side. Dragonflies have the ability to hover in mid-air for approximately one minute, unlike any other insect.
Dragonflies have six very thin, jointed legs and a very long and thin body, usually a few times longer than it is wide. They also have large heads with two large compound eyes relative to the rest of their bodies; each compound eye is made up of 28,000 individual units, referred to as ommatidia, which covers most of the head and an extendable jaw, which could be explained as a mouth that can lunge forward in order to catch prey. They are “semi-aquatic” meaning that they can breathe water through small gill-like holes called spiracles located in their abdomen; the water that is retained in their body is later squirted out giving the dragonfly a “quick jet-propelled movement.” Mature or adult Dragonflies are most easily recognized since they have the same characteristics as the immature or young Dragonflies (listed above), except that they have two pairs of membranous wing with a strong crossvein (small veins criss-crossing the wing) which add flexibility and strength the wing, which rests flat on either side of their elongated bodies, attached to their thorax. The wings have a nodus in the front edge of each wing. The rear wings are usually wider and larger than the front pair. This is what distinguishes them from Damselflies, since these insects are able to maintain their wings folded over their bodies through small hinges on their thorax. While mature Dragonflies range in the color of their fragmented abdomen, most immature Dragonflies have algae growing on them, which colors them brown or green.
Dragonflies are ectothermic insects, meaning that they use heat attained from their surroundings and behavioral acclimatization to regulate body temperature. Among Dragonflies exists a sexual dimorphism correlated to females; consequently, female Dragonflies are longer, wider and more brightly colored; although, the wings of male Dragonflies are relatively longer and thinner than those of females’.
Dragonflies usually live in environments with existing ponds, or shallow water sources. They usually stay near the water but sometimes migrate for feeding purposes. Their living environments include: lakes, rivers, streams, shallow water ponds, marsh, swamp, bogs and rainforests.
Dragonflies are subject to metamorphosis, which means that the insect will completely change in order to be considered a “mature Dragonfly.” They are seasonal breeders that reproduce sexually; meaning that males mate with females, who then lay the eggs usually at the end of autumn so that the nymphs can hatch from the eggs at the beginning of spring.
They are diurnal creatures that have the capacity to move from one place to another. They are also migratory and nomadic insects, meaning that they migrate between breeding and wintering grounds and usually travel not far away from their homing grounds to prey on other insects. Dragonflies are solitary insects, although very territorial; they defend the area around what they define as home, which is an area occupied by the same species.
Dragonflies communicate visually, thanks to their large compound eyes; this is the main reason why male Dragonflies fight “aerial duels for territory,” where they display their size and speed compared to one another. Mating couples communicate by touch as well, and recently it has been believed that they can communicate chemically, although no further research or experimentation has been conducted.
Dragonflies are the main predators in ponds with no fish, and mature Dragonflies help control the population of mosquitoes and flies. Humans get the added benefit of having these insects pest control the environment we share.
Since they are very fast fliers, Dragonflies prefer to catch their prey in open fields, rather than in forests or areas with a lot of bushes and trees. Although some people believe that they harm people they don’t, but there have been cases in which large Dragonflies attempt to bite humans but cannot “rip-through” the skin; making them seem as innocuous. Dragonflies definitely are insects that interact well with humans and the environment, since they just fly around looking for food and pest control other insects making humans’ lives easier.
