THE DIVERSITY OF FLYING INSECT LIFE THAT HAS EVOLVED

Insects are small animals around us. They are regarded as invertebrate animals. They are grouped in the class Insecta. The insects are the largest and “most widely distributed taxon in the phylum Arthropoda” (3). They seem to be consisting of six legs and the three body parts. Their body parts are namely; the head, thorax and abdomen. Some of the insects are having one pair of wings, others are having two while some are having three pairs of wings (3).


Ancient types of insects were seen since the early dinosaur days. It seems as if these types of insects evolved for flying long time ago before some of the birds could fly. The class insecta is divided in to two subclasses, which are further divided into orders. The sub class Apterygota is divided into two orders, the microcoryphia known as “dragonflies, damselflies and the zygentoma known as silverfish, fibre brats” (3). These insects were known to be jumping insects, because they did not have wings. It seems as if they were indoors types of insects, spending much of their time under the sinks, bookshelves, etc (2).


The dragonflies and the damselflies are the insects of the subclass Apterygota. These insects evolved into the subclass zygentoma. According to the Insecta the insects in the sub class Apterygota are wingless. The lack of wings of these insects resulted as their disadvantage of being diverse. “After the insects gained the ability to explore more territory, they found new type of food which increased more species” (2). This resulted when they evolved the ability to fly. For example: the insects from the microcoryphia order evolved into the Odonato order (2).


The Odonato insects had about two pairs of wings. They were regarded as the best fliers. These insects were eating other insects caught on fight (1). The early flying insects seem to have expanded wings that stuck straight. It really shows that insects did not only develop for flight, in the past 300 million years ago, some of the insects had evolved folding wings. This modernism really gave the diversity of insect’s improvement. Those insects can keep their wings safely tucked away as “they move slowly through leaf litter, squeezed under tree bark or even dived into water” (3).


The evolution of insects became successful because of the plants. The insects depend on the plants for their survival. It seems as if plants play important role to insects, for example, by providing large amount of food for the insects. The insects evolved “defences against the sophisticated chemical weapons in plants”. There are some of the insects that are able to recycle the poisons from the plants, for example monarch butterflies (1).


Evolution happens every where, even in insects evolution took place. Some of the insects descended from other insects, for example fleas descend from mosquito. Fleas are just like the scorpion flies, “they have long wings and powerful eyes, aiding them in finding insect carcasses for food” (3). The boreids are known to be the flea’s closet relatives alive. The boreids seems to have the knowledge on how the scorpion flies evolved. “These 24 species walk across snow in late winter to feed on moss. Unlike other scorpion flies, snow fleas have tiny wings that are useless for flying. They don't have the keen eyesight of other scorpion flies, probably because they need their eyes only to detect predators” (3).



References:


[1]. [http://www.universityscience.ie/pages/scimat_evolving_insects.php, accessed on 07/05/2006: 09:00].


[2]. The family tree, [http://www.insecta.com/insecta/tree.htm, accessed on 06/05/2006, 12:00].

[3]. Wikipedia contributors. Insect [Internet]. Wikipedia, The Free Encyclopedia; 2006 May 06, 12:59 UTC [cited 2006 May 23]. Available from: http://en.wikipedia.org/wiki/insects.



Ms Evelyn Maleka
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