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Classification of insects


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Classification of insects

  1. 1. An Assignment forPartial FulfilmentOfENT-504(CLASSIFICATION OF INSECTS)OnNEUROPTERAPrepared by:Mayank V. Patel(2ndsem.)Reg. No. 04-1904-2012Submitted to:Dr. D. M. KoratAssistant Director of ResearchAAU, ANAND
  2. 2. NeuropteraThe name Neuroptera is derived from the Greek word"neuron" meaning sinewand "ptera" meaning wings. The modern English translation "nerve-wings" isappropriate because it alludes to the extensive branching found in the wing veins ofmost Neuroptera.Scientific classification :-Kingdom AnimaliaPhylum ArthropodaClass InsectaSubclass PterygotaInfraclass NeopteraSuperorder EndopterygotaOrder NeuropteraSuborder Planipennia, MegalopteraExampleLacewing, Dobsonfly,Ant lion
  3. 3. Classification• Holometabola– complete development (egg, larva, pupa, adult)• Neuroptera is divided into two suborders:– Planipennia (antlions, lacewings and their relatives)– Megaloptera (alderflies and dobsonflies)Raphidiodea (snakeflies)• In adults, the suborders are distinguished by the shape of the wings and thelength of the prothorax.• In larvae, the suborders are separated by habitat and characteristics of themouthparts.Morphological characteristics Four membranous wings with many crossveins and extra branches of thelongitudinal veins. Fore and hind wings similar in shape andvenation. Held roof-like over the body atrest. Soft-bodied Mouthparts mandibulate Antennae long and many segmentedBiological summary for the orderLife history• Eggs -– Sialidae - laid in even rows of 300-900 in compact masses onsubstrates overhanging aquatichabitat.
  4. 4. – Rhaphidiidae - eggs laid under bark and hidden areas.– Sisyridae - masses of 2-5 oval whitish to yellow eggs are covered with aweb of white silk.– Laid singly or in clusters at the end ofsilken threads in many families.• Larvae -– Megaloptera• Aquatic• Many instars with 1-5 years to develop. Late stage larvaeabundant in late winter or early spring.– Raphidiodea> Live under bark of trees and in soil.> Semi voltine with 10-11 instars.> Overwintering occurs in larval stage andoccasionally in pupal stage.– Planipennia• Terrestrial• Usually 3 larval instars• Overwinter in all stages except eggs.• Pupae– Often form a silken cocoon to pupate or pupalcells in soil or organic material.– Some pupae are able to move about prior toecdysis.
  5. 5. Adult– Antennae filiform,multisegmented– Chewing mouthparts– Fore and hind wingmembranous, similar in size– Extensive branching ofvenation in all wings; crossveins abundant especially along leading edge(costal margin)Habitat• Aquatic species live adjacent to water. Sialidae adults are found on shore plantsbeside slowly flowing water near their larval habitat.• Terrestrial species variable living on plants and stalking prey or under bark.Habits (mode of existence)• Most are predaceous as adults and larvae in aquatic and terrestrial habitats.• Some do not feed.Economic Importance• Larvae of Megaloptera are important predators in aquatic ecosystems. Theyalso serve as food for fish and other aquatic vertebrates.• Lacewing larvae are beneficial as predators of agricultural pests (aphids,whiteflies and scale insects).• Some species are reared and sold commercially as biocontrol agents.
  6. 6. Important families with suborders Planipennia :-– Chrysopidae -- Green lacewings– Hemerobiidae -- Brown lacewings– Myrmeleontidae -- Ant lions– Sisyridae -- Spongeflies– Mantispidae – Mantidflies– Ascalaphidae -- Owlflies Megaloptera :-– Corydalidae -- Dobsonflies– Sialidae -- Alderflies– Raphidiidae -- SnakefliesChrysopidae• E.g. Green lacewing (Chrysoperla spp.)• Most larvae are active predators and havemodified jaws, which they use to catchsmall insects and suck out their insides.(Suctorial type mouth part)Hemerobiidae• These insects differ from the somewhatsimilar Chrysopidae(green lacewings) notonly by the usual colouring but by the wingvenation: hemerobiids having numerouslong veins lacking in chrysopids.• Some of the costal cross veins are forked,unlike in green lacewings.
  7. 7. • Hemerobiid larvae are usually less hairy than chrysopid larvae• Adults & Larvae both are predaceousMyrmeleontidae• E.g. Ant lion (Distoleon tetragrammicus)• Ant lions are weak fliers as adults.• The pits are dug in loose sand and as therename suggests there main food items areoften ants.• The larvae will interfere with any ant thatlooks like it might be getting out of the pit byflicking grains of sand at it to make it looseits footing and thus fall into the waitinglarvaes jaws.• There are about 2,000 species of ant lions in the world.Mantispidae• E. g. Mantispa sp.• Mantidflies often referred to as Mantispidspossess raptorial forelegs much like those ofthe similarly named praying mantids whichthey use in the same way.• The males use pheromones instead of sound toattract females. During courtship the male raises his forelegs in the air whileraising and lowering his wings.• The eggs like those of the Green Lacewings are laid at the end of a thin stalk.The eggs soon hatch and immediately enter a state of diapause.Corydalidae• E.g. Dobsonfly (Corydalus cornutus)• Wingspans can be twice as long as their body length.• Dobsonflies spend most of their life in the larval stage,during which they are called hellgrammites.
  8. 8. • Hellgrammites live under rocks at the bottoms oflakes, streams and rivers, and prey on other insectlarvae with the short sharp pincers on their heads, withwhich they can also inflict painful bites on humans.The larvae reach up to 2" to 3" in length, with gills allalong the sides of their segmented bodies that allowthem to breathe underwater.• Their gills, primitive nervous systems, and hard, segmented bodies meanshellgrammites can survive for long periods underwater.Sialidae• E.g. Alderfly (Sialis lutaria)• They lack ocelli and their fourth tarsal segment isdeeply bilobed.• Dead alderfly larvae are used as bait in fishing.Raphidiidae• E.g. Snakeflies (Raphidia notata)• Long-necked predators of small arthropods• Adult snakeflies are characterized by having an elongateprothorax but no modification of the forelegs. They havestrong and relatively unspecialised mouthparts, and largecompound eyes.• The females typically have a long ovipositor, which theyuse to deposit their eggs into crevices in bark or rottingwood. The wings are similar in size, with a primitivevenation pattern, and a thickened costal margin.• The larvae have large heads with projecting mandibles.The head and the first segment of the thorax aresclerotised, but the rest of the body is soft and fleshy.• They have three pairs of true legs, but no prolegs.
  9. 9. • However, they do possess an adhesive organ on the abdomen, with which theycan fasten themselves to vertical surfaces.• The larvae can take up to two years to develop.Difference between Brown Lacewing & Green LacewingBrown Lacewing Green LacewingE.g. Hemerobius stigma E.g. Chrysoperla carnea StephensWings are brown in colour Wings are green in colourAdults & Larvae both are predaceous Only Larval stage is predaceousPresence of hook on backside of larvae Absence of hook