Typical Flies: Natural History, Lifestyle and Diversity of Diptera

*Muhammad Sarwar*

## **Abstract**

The Order Diptera, comprising of two-winged or true flies, is one of the most commonly recognized and widespread insects all over the world. During their long evolutionary history, virtually every terrestrial and aquatic niche has been occupied by Diptera, thus making these one of the most successful groups of organisms on earth. The main purpose of this chapter is to provide modern, well-illustrated and easily interpretable information for economic importance, life histories, habits and habitats, lifestyles, diversity, identifying and studying, pharmaceutical and industrial applications, ecological and human services, pests and vectors of diseases, predators and herbivores, pollination and biological control agents, association with carcasses, forensic science, phylogeny and classification of Diptera. Without doubt, this fragment of book provides the basics for understanding diversity of a major order of insects and is the first such synopsis of its kind for scientists and public alike.

**Keywords:** flies, vectors, pests, ecosystem engineer, forensics

#### **1. Introduction**

The so-called true flies are one of the utmost important groups of insects in the order Diptera. The name Diptera, is derived from the Greek words '*di'* meaning two and '*ptera*' hereby meaning wings, which refers to the fact that true flies have only a single pair of wings (two wings). This is distinguishing character because other insects have either two pairs of wings or four wings. Diptera's ancestors also have four wings, but in dipteran insects, second pair of wings is evolved into halteres, which are modified balancer organs that give to insect an amazing amount of fine control while flying.

Many winged insects, such as the butterfly and whitefly, contain the word 'fly' in their names, but are not dipterans, and the name is strictly applicable only to members of Diptera. There is an accepted custom for writing the common names of insects, which have included the word 'fly'. When any name is for a group of insects other than Diptera, it is written as single word (mayfly, dragonfly, and stonefly). But, if an insect belongs to Diptera order and word 'fly' is included, the name is written as double words (horse fly, black fly, crane fly). Diptera is one of the largest insect orders and quite diverse with its numbers more than 125,000 species worldwide. Our world's score of more than 152,000 described species within more than 130 known families is based primarily on figures extracted from the 'BioSystematic Database of World Diptera' [1].

The close association of dipteran flies with humans has led them to be recognized as unpleasant and disturbing creatures, and certainly some flies are responsible for millions of illnesses and deaths among human populations. Yet flies are also among the key components in most ecosystems and known advantageous in many ways. Voluminous flies are of great economic importance because some bloodsuckers are serious pests of humans and other animals. These insects are key vectors of some diseases, although others are pests of cultivated plants. Flies are advantageous as well by operating as predators or parasites of certain insects, scavengers as well as pollinators of plants and killers of weeds harmful to persons. Often called maggots or grubs, dipterous larvae, are found in many habitats (in water, plant tissue and soil, animal matter and decaying plants, below stones or bark, pools of crude petroleum), whereas adults forage on plant or animal juices or other insects. Diptera falls into three big sets, Nematocera (flies with multi-segmented antennae such as crane flies, midges, gnats, mosquitoes), Brachycera (flies with stylate antennae, for instance, horse flies, robber flies, bee flies) and Cyclorrhapha (flies with aristate antennae, such like, flies that breed in vegetable or animal material, both living and dead) [2, 3].

develops in ponds of crude oil; and brine fly *Ephydra cinera* Jones, may live in

The arista in the antenna of higher flies is an air speed indicator and it permits an insect to sense precisely just how fast it is moving. As black fly pupae mature, they become inflated with air. The pupal skin pops open upon emergence, and the fullygrown fly inside a bubble of air floats to water surface and it never even acquires its feet wet. The little scuttle fly *Megaselia scalaris* (Loew) is actually an omnivore. It has been cultured on paint emulsions, decaying vegetation, shoe polish, human dead body kept in formalin and even lung tissue from living people. As Diptera comprises the most ecologically diverse order of insects, swamps (wetlands ecosystem) resembling to this one (**Figure 1**) inundated by water and dominated by plant

Diptera have successfully colonized all continents including Antarctica, and are diverse not only in species richness, but also in their structure, habitat exploitation,

Maximum of nourishing and buildup of biomass take place in the larval stages and adults Diptera generally take energy they require to supply their flight muscles. Among those flies that forage widely, their foods contain honeydew or nectar (Blephariceridae and Bombyliidae), vertebrate blood (Culicidae and Glossinidae),

Empididae and some Scathophagidae), while those of a few Diptera (Oestridae and Deuterophlebiidae) that totally lack of mouthparts, do not take food and live only

Larvae of most species can be considered aquatic for existence, they need moist to wet atmosphere inside living tissues of plants, within decaying organic matters, as parasitoids or parasites of animals, or else are in link with water bodies. Maximum of larvae are free-living and crawl, tunnel or swim vigorously in water (Culicidae, Chironomidae, Chaoboridae, Simuliidae), sediments (Tabanidae, Tipulidae, Ceratopogonidae, Psychodidae), wood (Axymyiidae, Tipulidae, some Syrphidae), fruits (Tephritidae, Chloropidae), or decomposing biological material (Muscidae, Ephydridae, Sphaeroceridae, Sarcophagidae), whereas other larvae dwell in the tissues of alive creatures (Oestridae, Acroceridae, Tachinidae,

The utmost essential significance of flies is not based only on limited acquainted

families that comprise mosquitoes, tsetse flies, houseflies and other annoyance insects, but rather in the huge numbers of unfamiliar species that are a vital component in food chains upon which much of life rests on. Flies are of considerable ecological importance and their abundance, worldwide distribution and habits combine to make them a nuisance to humans by landing on people or entering homes or businesses. Midges and gnats are common names for a large number of small, non-biting flies and an important part of aquatic food chains. Swarms or clouds of midges in the air are a collective nuisance. Face flies and sweat flies, gather

pollen (Nemestrinidae and Syrphidae), insect hemolymph (certain

Ceratopogonidae) and other biological resources that are liquefied or can be suspended or dissolved in regurgitated fluid or saliva (Muscidae, Calliphoridae and

Micropezidae). The grownups of several groups are predaceous (Asilidae,

extraordinary concentrations of salt [4].

*DOI: http://dx.doi.org/10.5772/intechopen.91391*

*Typical Flies: Natural History, Lifestyle and Diversity of Diptera*

life, are great places to find its members.

life habits and interactions with humankind [5].

**3. Diversity among Diptera**

for a short period [6].

Pipunculidae) [7].

**3**

**4. Prominence of Diptera**
