Dr. M. K. Nayak Assistant Professor, Entomlogy Subject: Fundamental of Entomology College: College of Agriculture, Tikamgarh Lecture Title: ORDER: DIPTERA Etymology: Di: Two; ptera: wings Example: True flies, Mosquitoes, Midge etc Important character 1. They are small to medium sized, soft bodied insects. 2. The body regions are distinct. 3. Head is often hemispherical and attached to the thorax by a slender neck. 4. Mouthparts are of sucking type, but may be modified. 5. Antennae mostly 3 segmented (except in Nematocera ) and aristate 6. All thoracic segments are fused together. The thoracic mass is largely made up of mesothorax. A small lobe of the mesonotum (scutellum) overhangs the base of the abdomen. 7. Legs well developed, tarsus usually 5 segmented pulvilli and an empodium Usually present 8. They have a single pair of wings. 9. Forewings are larger, membranous and used for flight. 10. Hindwings are highly reduced, knobbed at the end and are called halteres . They are rapidly vibrated during flight. They function as organs of equilibrium. Flies are the swiftest among all insects. 11. Metamorphosis is complete. Larvae of more common forms are known as maggots. They are apodous and acephalous . Mouthparts are represented as mouth hooks which are attached to internal sclerites. Pupa is generally with free appendages, often enclosed in the hardened last larval skin called puparium . Pupa belongs to the coarctate type. Classification This order is sub divided in to three suborders. Difference among suborder of Dipteral order: Character Nematocera Brachycera cyclorrhapha Larva Eucephalous Hemicephalous Acephalous Antennae 1-6 segmented Reduced, papillae like absent Mouthpart Well developed, Well developed, Reduced (Cephalopharyngeal Mandibles vertically skeleton bearing mandibular hook, articulated hypostomal and pharyngeal sclerite) Pupa obtect obtect exarate Instar 4 5-8 3 Alimentary Short straight Slightly convoluted Long and coiled canal Palpi 4-5 segmented 2-3 segmented Single segmented Antennae in Longer than body 3 segmented , Stylet 3 segmented, Aristate type Adult (Filiform) type wing Discal cell absent present Present Cubital cell Widely open closed Closed Salivary Tubular trilobed Tubular running upto Coiled elongated more than a glands some length of length of abdomen abdomen Important character of family under Sub order : NEMATOCERA Family: Cecidomyiidae (Gall midge) 1. They are minute delicate, mosquito like flies. 2. Antennae long, moniliform with whorls of hairs. Legs long resembling mosquitoes 3. Wing venation is reduced. Wings are covered with long hairs. 4. A dark sclerotised area is present midventrally on the prothorax in the larva called `chest bone'. Eg: Rice gall midge -Orseolia oryzae Family: Culicidae (Mosquitoes) 1. They are delicate, fragile, slender insects 2. Females have piercing and sucking type of mouthparts with six stylets. 3. Antenna is plumose (bushy) in male and pilose (less hairy) in female. 4. Legs are slender, delicate and long. 5. Wings are fringed with hairs and scales on hind margin and on some veins. 6. Males are short lived and feed on nectar or decaying fruits. 7. Females live long and are blood feeders. 8. Larvae are called wrigglers . 9. Pupa is known as tumbler . Important character of family under Sub order : BRACHYCERA Family: Asilidae (Robber flies) 1. They are elongate bristly flies. 2. Head is broad and hollowed out in between the compound eyes. 3. Compound eyes are protuberant. A prominent tuft of hairs is found on the head forming the mouth-beard. The proboscis is thick and stout. 4. Legs are stout, hairy and suited for catching the prey. 5. Abdomen is tapering and has a pair of large claspers at the tip of the male and a horny ovipositor in female. 6. They are most active , non selective predators. Family: Tabanidae (Horse flies) 1. Body is stout. 2. Head is large. Eyes are large and often brilliantely coloured. In male eyes are holoptic (contiguous) and in female dichoptic (seperate). The third antennal segment is annulated. The proboscis is strong and pointing downwards. 3. They are swift fliers. 4. Male feeds on nectar. Female sucks blood from cattle and horses. They spread anthrax. Important character of family under Sub order : CYCLORRHAPHA Family: Tephritidae (Trypetidae) 1. Small to medium flies, slightly hairy / bristly 2. Head large broad with small neck 3. Wings large mostly pictured. Sub Costa bends apically formed at almost a right angle and then fade out without reaching the margin 4. Middle legs tarsi with spurs 5. Ovipositor very well developed horny and flattened and usually 3 segmented 6. Adults are visitors of flowers, fruits and foliage 7. Larvae phytophagous, Amphipneustic (1st’s last pair of spiracle functional) Eg : Fruit fly on cucurbit - Dacus cucurbitae, Fruit fly on guava- Chaetodacus incises Family: Agromyzidae (Leaf miner flies) 1. These are small blackish or yellowish flies 2. Femora of the legs bristled 3. Wings by hyaline or pictured 4. Vibriosae are generally present (a pair of stout bristles on each side of the face just above the oral margin longer than other bristles on the vibrissal ridge) 5. Most of the larvae are phytophagous, mine in the leaves producing characteristic blotches Eg: Redgram podfly - Melanagromyza obtuse, Pea leaf miner -Phytomyza atricornis Family: Tachinidae 1. Small to medium, conspicuously bristly or hairy, active flies 2. Head is large and free. Arista on antennae often bare 3. Pteropleural bristles are present. Post scutellum is prominent 4. Wings are large , rarely mottled, Rs cell narrowed or closed apically 5. Abdominal sternite usually overlapped by the tergites on the sides. Abdomen clothed with long, conspicuous marginal, dorsal and apical bristles 6. Larvae mostly parasitoids. Few are saprophagous. Metapneustic in first instar and amphipneustic subsequently. Distinctly segmented Eg. Sturmiabimaculata – parasitoid on Spodopteera and other caterpillars Family: Muscidae (Flower flies, root maggots, shoot flies, house flies) 1. Small to medium dark coloured flies 2. Fine erect hairs are present on the under surface of scutellum (mesothorax portion) and have more than one stero pleural bristles. 3. Abdomen bristly with somewhat constricted base usually 4-5 segmented Vein Cu2 + 2A is short and do not reach the wing margin 5. Larvae cylindrical and truncate posteriorly some are phytophagous, some are saprophagous while a few are parasitic. Eg: Jowar shootfly -Atherigona soccata . .