**8. Nutritional requirements of Diptera**

Nutrition involves balance between feeding habits of larval and adult flies, and primary feeding occurs during the larval stage. Adult feeding serves to compensate the shortcomings of larval nourishment. Adult flies often drink upon fluids, but some feed on any liquid that has nutrients. They also can 'spit' onto dry food and then suck up the spit and some extra nourishment from the dry food, and thus infect human food. Certain female flies suck vertebrates blood, for instance from mammals to get protein they need for their eggs. A small number of adults are predators; they grasp other insects, crack them with their mouthparts and draw out their organs and fluids [45].

Generally pupae do not feed, and several flies do maximum of their nourishing as larvae and fly larvae often feed continuously during day and night. Certain feed on plants or eat fungi, but mainly upon fruits. Certain species are gathering collectors (feed on organic detritus), filtering collectors (feed on suspended diatoms and fine detritus filtered from water column), scrapers (use mandibles to scrape algae and fungi), shredders by chewing and boring (feed on leaf litter or living macrophytes) and predators prey on other invertebrates including their own species. Some place their eggs in leaves or stems and their larvae emit chemicals that make the plant to swell up into a gall. This defends the fly larva and provides to it a sufficient of nutrition to feed. Further species consume deceased animals and several feed on dung. Certain filter microscopic diet elements from freshwater (river, lake, stream). A single large group of flies in nature is parasitic, these deposit their eggs outside or inside of other insects and spiders, and their larvae nourish on inside of hosts even though host is still thriving. A limited species are vertebrate parasites, like birds and mammals and live under the skin or into wounds of their hosts. Several dipteran larvae live in aquatic, semi-aquatic or wet terrestrial atmospheres. They are normally found in soil, animal tissues or plant and in carrion or dung, where there is almost always a little risk of desiccation. Certain species are herbivores; however maximum forage on dead biological matter or parasitize other animals, particularly vertebrates, mollusks and many other arthropods.

At one extreme are nonbiting midges, with larvae that vigorously filter microorganisms from water. Correlating to nonbiting midges are biting midges, black flies and mosquitoes. Female adults in these families need supplementing diet in an insufficient larval food. Even though one set of eggs rarely is put deprived of a blood food, but blood is essential to develop a subsequent lot. Flies, which place one egg batch devoid of blood, are termed autogenous and those that cannot lay without

#### *Typical Flies: Natural History, Lifestyle and Diversity of Diptera DOI: http://dx.doi.org/10.5772/intechopen.91391*

Within more primitive families in suborder Nematocera, larvae of flies have well-built head capsules having mouthparts of mandibulate type. These arrangements are absent or reduced in more progressive Brachycera and Cyclorrhapha suborders wherein larvae are recognized as maggots, having worm-like bodies and a couple of mouth hooks only for nourishing. The abdomen, thorax and legs of adult flies differ from short to long and appearance of fly is well-designed along with decorative style. From time to time, bright color and pattern of several flies (blow flies) is metallic, on the other hand, most often fly is concealed with a good coating called dusting or tomentum. Numerous flies, principally those of more greatly evolved families, are bristly and the strongest bristles have an accurate location, mostly on thorax. The identification of bristles, their arrangement and the method

Nutrition involves balance between feeding habits of larval and adult flies, and primary feeding occurs during the larval stage. Adult feeding serves to compensate the shortcomings of larval nourishment. Adult flies often drink upon fluids, but some feed on any liquid that has nutrients. They also can 'spit' onto dry food and then suck up the spit and some extra nourishment from the dry food, and thus infect human food. Certain female flies suck vertebrates blood, for instance from mammals to get protein they need for their eggs. A small number of adults are predators; they grasp other insects, crack them with their mouthparts and draw out

Generally pupae do not feed, and several flies do maximum of their nourishing as larvae and fly larvae often feed continuously during day and night. Certain feed on plants or eat fungi, but mainly upon fruits. Certain species are gathering collectors (feed on organic detritus), filtering collectors (feed on suspended diatoms and fine detritus filtered from water column), scrapers (use mandibles to scrape algae and fungi), shredders by chewing and boring (feed on leaf litter or living macrophytes) and predators prey on other invertebrates including their own species. Some place their eggs in leaves or stems and their larvae emit

chemicals that make the plant to swell up into a gall. This defends the fly larva and provides to it a sufficient of nutrition to feed. Further species consume deceased animals and several feed on dung. Certain filter microscopic diet elements from freshwater (river, lake, stream). A single large group of flies in nature is parasitic, these deposit their eggs outside or inside of other insects and spiders, and their larvae nourish on inside of hosts even though host is still thriving. A limited species are vertebrate parasites, like birds and mammals and live under the skin or into wounds of their hosts. Several dipteran larvae live in aquatic, semi-aquatic or wet terrestrial atmospheres. They are normally found in soil, animal tissues or plant and in carrion or dung, where there is almost always a little risk of desiccation. Certain species are herbivores; however maximum forage on dead biological matter or parasitize other animals, particularly vertebrates, mollusks and many

At one extreme are nonbiting midges, with larvae that vigorously filter microorganisms from water. Correlating to nonbiting midges are biting midges, black flies and mosquitoes. Female adults in these families need supplementing diet in an insufficient larval food. Even though one set of eggs rarely is put deprived of a blood food, but blood is essential to develop a subsequent lot. Flies, which place one egg batch devoid of blood, are termed autogenous and those that cannot lay without

established on them is known as chaetotaxy [43, 44].

**8. Nutritional requirements of Diptera**

*Life Cycle and Development of Diptera*

their organs and fluids [45].

other arthropods.

**14**

blood at all are anautogenous. One species may have both types, probably as a result of unstable populations otherwise races rising from usual selection. Such as far north, great densities of biting flies (horse flies, black flies, biting midges mosquitoes) arise for the period of small Arctic summer and there are noticeably inadequate amounts of warm-blooded animals to offer diet. If flies clip blood, they consume it; however, these still stay alive, if not availed.

The adults do not feed and most flies visit flowers, which provide water, nectar and pollen. Although the name *Drosophila* means 'lover of dew', this insect sucks water and any other obtainable fluid. Nectar from flowers contains carbohydrates and most adult flies use this syrupy liquid. Pollens are tougher to obtain for a sucking insect than blood, which is rich in protein and a vital source of this nutrient. Several hover flies love pollen grains among hardened portions of labella prior to swallow them and certain flies actively probe into flowers, covering their eyes and heads with pollen grains. Although their role in pollination is less well known than that of bees, flies are important pollinators of flowers. Some plants (spurges) are often covered with small flies of different families. Small flies also feed on honeydew from aphids or whiteflies. Flies forage on dung and fluid produces of either vegetable decay or animal. They get nutrients from garbage dumps and farmyard manure heaps. These dwellings as well harbor several larvae, which nourish either right on biological diet available or feed on other larvae as carnivorous. Yellow dung fly larvae and adults, is a familiar example that target on other insects coming to dung [35, 36, 46].

Adaptableness of flies is obvious on a widespread range of foods consumed by the larvae. Aside from parasites, the maximum specific feeders are those larvae, which live in plant tissues (leaf mining Agromyzidae, may be limited to group of plants or one plant species). Commonly, pests of horticulture and agriculture (cabbage root fly) are multipurpose species, nourishing on a diversity of wild type hosts and altering their foods while offered with intense plantings of marketable crops. Numerous carnivorous larvae of fly (asilids) most likely reside in soil and consume animal or vegetable material, whatsoever is accessible. Meanwhile adult robber flies (asilids), forage on various insects, their larval diet is recognized to be insufficient. Certain maggots, predominantly young insect, which forage on plant material for the duration of second and first instars, turn into carnivorous in the course of third instar, where maximum of development occurs.

Adult flies escape from predators with their alertness and speed. Likewise, several flies mimic stinging insects, for instance, bees or wasps, therefore predators will avoid them. Larvae habitually live in dwellings that are hard to reach by predators. Well-known predators of flies are shrews (eat larvae and pupae), rodents (pupae), moles (larvae and pupae), toads (mostly adult flies), frogs (mostly adult flies), birds, ants, wasps, other flies, spiders, ground beetles (larvae and pupae) and true bugs (larvae and pupae).

In many cases, only the adult females of biting flies under certain circumstances get blood diet, Culicidae family of mosquitoes, possibly spreads dengue, malaria, filariasis, encephalitis, yellow fever and other illnesses. Tabanidae (deer flies/ horse flies) can transmit loiasis, trypanosomiasis, tularemia and some other sicknesses. Simuliidae family of black flies feasibly spread onchocerciasis of human and leucocytozoon contaminations in poultry. Moth flies of Psychodidae can transmit leishmaniasis, sand fly fever and further diseases. Family Ceratopogonidae having punkies and no-see-ums are small and on the other hand vicious biters associated to transmit some protozoan, roundworms and virus pathogens in animals and humans. Muscidae family of house flies is among the utmost cosmopolitan than all other insects. Particular species have piercing mouthparts while some others are

only scavengers, and diseases such as cholera, yaws and dysentery can be transferred on their mouthparts and feet.

**9. Roles in the ecosystem**

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

animals.

to a few years [49].

**Figure 6.** *Black fly.*

**17**

state of fly's growth existing on carcass.

The prime advantage of flies originates from the parasitic species. They invade grasshoppers, caterpillars and other insects that damage to food plants. Certain flies are also important pollinators and aid to pollinate plants that are grown. Flies are likewise essential food basis for other animals that are valuable such as fish. Many fly larvae are part of the natural clean-up squad, helping to get rid of dung and dead

Marine Diptera, which perform decomposers function are land-dwelling muscoid flies, for instance, in aquatic habitations, Calliphoridae are under-

represented mainly when a carcass is fully underwater. Corpses floating on surface of water and alongside shorelines, deal a terrestrial-aquatic boundary, which is expected to comprise dipteran agents of both surroundings. Certain ephydrids of shore-inhabiting devour minor carcasses of animals on seashores, suggestive of their legal prospective to as well practice bigger carcasses. Forensic circumstances in water linking to a deceased person normally feature presence of chironomids, their abundance, diversity, ubiquity and species-specific appearances, which make to Chironomidae possibly beneficial in criminal inquiries. Adhoc examples to utilizes marine Diptera in legal inquiries have been recognized. Exuviae of black fly

*Prosimulium fuscum* (Syme & Davies) (**Figure 6**) pupae found on a submerged case helped to convict a murderer by countering his purported timeline of events [48]. Forensic entomology creates use of information resulting from either the series of arthropods on animal carcasses or human corpses or temperature-dependent development of insects (principally flies) to appraise the time gone since passing away or postmortem interval (PMI) or estimate of the time between death and corpse detection. Flies are the most significant organisms for forensic study and especially valuable in determining the age of corpse from duration of a few hours

The occurrence of insects within any carcass is a serious sign toward guessing death time of bodies deceased for lengthier time periods. Since, flies quickly find out a body and their times of growth are foreseeable during specific ecological circumstances, so death time may be determined by calculating back days from the

**9.1 Decomposition: fly life cycle and development times**

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

Larvae of herbivores flies forage on plant tissues, some gall midges (Cecidomyiidae) bring creation of plant galls, some are parasites, predators or scavengers and this family primarily comprises the Hessian fly *Mayetiola destructor* Say. Numerous species of family Tephritidae (fruit flies) are agricultural pests, such as the apple maggot *Rhagoletis pomonella* (Walsh). Most larvae of family Agromyzidae are leaf miners, some are stem and seed borers, and many Anthomyiidae species are seed otherwise root maggots.

Scavenger larvae nourish in garbage, carrion, dung otherwise further biological material, pomace flies (Drosophilidae) larvae forage on rotting fruit, crane flies (Tipulidae) live in mud or soil, larvae of blow flies (Calliphoridae) nourish on carrion or garbage and include screwworm *Cochliomyia hominivorax* (Coquerel), midges (Chironomidae) aquatic larvae generally breath in mud and forage on biological material, and larvae of flesh flies (Sarcophagidae) usually nourish on carrion, but certain species can be source of human myiasis.

Predatory larvae or adults predate on other insects as prey and specific flies produce predatory maggots that feed on other maggots. The predatory maggots of *Chrysomya rufifacies* (Macquart) (bluebottle) are covered with spiny protrusions which deter other predators. Families such as Asilidae (robber flies) are wideranging predators of other insects, Bombyliidae (bee flies) has predatory larvae and adults mimic to bees, Syrphidae (flower flies) (**Figure 5**) have larvae that are aphid predators and maximum adults mimic wasps or bees, and Empididae (dance flies) adults are also predatory. Parasitic larvae are parasitoids or parasites of insects and animals. Families like Tachinidae have several species that are important biocontrol agents and parasitoids of other insects, Hippoboscidae (louse flies) adults are bloodfeeding ectoparasites of mammals and birds, larvae of Sciomyzidae (marsh flies) parasitize snails and slugs, and Oestridae (warble flies and bot flies) larvae are endoparasites of mammals as well as humans [47].

**Figure 5.** *(a) Robber fly, (b) Dance fly, (c) Flower fly, (d) Louse fly.*
