CATTER PILLER

                                                                                                                                              CATTER PILLER                                                                                                                                                                   Caterpillar is the common name for the larvae of members of the order Lepidoptera (the insect order comprising butterflies and moths). As with most common names, the application of the word is arbitrary and the larvae of sawflies commonly are called caterpillars as well.

Caterpillars of most species are herbivorous, but not all; some are insectivorous, even cannibalistic. Some feed on other animal products; for example clothes moths feed on wool, and horn moths feed on the hooves and horns of dead ungulates.

Caterpillars as a rule are voracious feeders and many of them are among the most serious of agricultural pests. In fact many moth species are best known in their caterpillar stages because of the damage they cause to fruits and other agricultural produce, whereas the moths are obscure and do no direct harm. Conversely, various species of caterpillar are valued as sources of silk, as human or animal food, or for biological control of pest plants.

Etymology

The origins of the word "caterpillar" date from the early 16th century. They derive from Middle English catirpel, catirpeller, probably an alteration of Old North French catepelose: cate.

Classification

The geometrids, also known as inchworms or loopers, are so named because of the way they move, appearing to measure the earth (the word geometrid means earth-measurer in Greek); the primary reason for this unusual locomotion is the elimination of nearly all the prolegs except the clasper on the terminal segment.

Caterpillars have soft bodies that can grow rapidly between moults. Only the head capsule is hardened. The mandibles are tough and sharp for chewing leaves (this contrasts with most adult Lepidoptera, which have highly reduced or soft mandibles). Behind the mandibles of the caterpillar are the spinnerets, for manipulating silk. Antennae are present on either side of the labrum, but small and relatively inconspicuous.

Some larvae of the Hymenoptera order (ants, bees and wasps) can appear like the caterpillars of the lepidoptera. Such larvae are mainly seen in the sawfly family. However while these larvae superficially resemble caterpillars, they can be distinguished by the presence of prolegs on every abdominal segment, an absence of crochets or hooks on the prolegs (these are present on lepidopteran caterpillars), prominent ocelli on the head capsule, and an absence of the upside-down Y-shaped suture on the front of the head.


chemical defenses

More aggressive self-defense measures are taken by some caterpillars. These measures include having spiny bristles or long fine hair-like setae with detachable tips that will irritate by lodging in the skin or mucous membranes. However some birds (such as cuckoos) will swallow even the hairiest of caterpillars. Other caterpillars acquire toxins from their host plants that render them unpalatable to most of their predators. For instance, Ornate moth caterpillars utilize pyrrolizidine alkaloids that they obtain from their food plants to deter predators.

The most aggressive caterpillar defenses are bristles associated with venom glands. These bristles are called urticating hairs. A venom which is among the most potent defensive chemicals in any animal is produced by the South American silk moth genus Lonomia. Its venom is an anticoagulant powerful enough to cause a human to hemorrhage to death (See Lonomiasis). This chemical is being investigated for potential medical applications. Most urticating hairs range in effect from mild irritation to dermatitis.

Plants contain toxins which protect them from herbivores, but some caterpillars have evolved countermeasures which enable them to eat the leaves of such toxic plants. In addition to being unaffected by the poison, the caterpillars sequester it in their body, making them highly toxic to predators. The chemicals are also carried on into the adult stages. These toxic species, such as the Cinnabar moth (Tyria jacobaeae) and monarch (Danaus plexippus) caterpillars, usually advertise themselves with the danger colors of red, yellow and black, often in bright stripes (see aposematism). Any predator that attempts to eat a caterpillar with an aggressive defense mechanism will learn and avoid future attempts.

Some caterpillars regurgitate acidic digestive juices at attacking enemies. Many papilionid larvae produce bad smells from extrudable glands called osmeteria.

CADDIS FLY

                                                                                                                                                                         CADDIS FLY                                                                                                                                                                                                                                                                              The caddisflies are an order, Trichoptera, of insects with approximately 12,000 described species. Also called sedge-flies or rail-flies, they are small moth-like insects having two pairs of hairy membranous wings. They are closely related to Lepidoptera (moths and butterflies) which have scales on their wings, and the two orders together form the superorder Amphiesmenoptera. Caddisflies have aquatic larvae and are found in a wide variety of habitats such as streams, rivers, lakes, ponds, spring seeps, and temporary waters (vernal pools).The larvae of many species use silk to make protective cases of gravel, sand, twigs or other debris. The name "Trichoptera" comes from Greek:(thrix, "hair") (pteron, "wing").

Ecology

Although caddisflies may be found in waterbodies of varying qualities, species-rich caddisfly assemblages are generally thought to indicate clean water. Together with stoneflies and mayflies, caddisflies feature importantly in bioassessment surveys of streams and other water bodies. Caddisfly species can be found in all feeding guilds in stream habitats, with some species being predators, leaf shredders, algal grazers, and collectors of particles from the watercolumn and benthos.

Underwater architects

Most caddisfly larvae are underwater architects and use silk, excreted from salivary glands near their mouths, for building.Caddisflies can be divided loosely into three behavioral groups based on their use of silk: net-making caddisflies and case-making caddisflies, both of which may enlarge their structures throughout their larval lifespan; and free-living caddisflies, which only make such structures prior to pupation. Net-making caddisflies usually live in running water, and their nets, often made amongst aquatic vegetation, serve both as a means to collect algae, detritus, and animal food and as retreats.

Case-making caddis flies may build cases exclusively of silk, but more commonly the silk holds together substrate materials such as small fragments of rock, sand, small pieces of twig or aquatic plants. Caddisfly cases are open at both ends, the larva drawing oxygenated water through the posterior end, over their gills, and out of the wider anterior end. The anterior end is usually wider and it is to this end that they add material as they grow.

Their abdomens are soft, but their tougher front ends project from their larval tubes, allowing them to walk while dragging their cases along with them. Caddisfly cases resemble bagworm cases, which are constructed by various terrestrial moth species. Free-living caddisflies do not build retreats or carry portable cases until they are ready to pupate, and their bodies tend to be tougher than the building.


Development


Many species of caddisfly larvae enter a stage of inactivity called the pupa stage for weeks or months after they mature but prior to emergence. Their emergence is then triggered by cooling water temperatures in the fall, effectively synchronizing the adult activity to make mate-finding easier. In the Northwestern US, caddisfly larvae within their gravel cases are called 'periwinkles.

Caddisfly pupation occurs much like pupation of Lepidoptera. That is, caddisflies pupate in a cocoon spun from silk.Caddisflies that build the portable cases attach their case to some underwater object, seal the front and back apertures against predation though still allowing water flow, and pupate within it. Once fully developed, most pupal caddisflies cut through their cases with a special pair of mandibles, swim up to the water surface, cast off skin and the now-obsolete gills and mandibles, and emerge as fully formed adults. In a minority of species, the pupae swim to shore -- either below the water or across the surface -- and crawl out to emerge. Many of them are able to fly immediately after breaking from their pupal skin.

The adult stage of caddisflies, in most cases, is very short-lived, usually only 1–2 weeks, but can sometimes last for 2 months. Most adults are non-feeding and are equipped mainly to mate. Once mated, the female caddisfly will often lay eggs (enclosed in a gelatinous mass) by attaching them above or below the water surface. Eggs hatch in as little as three weeks.

Caddisflies in most temperate areas complete their life cycles in a single year.The general temperate-zone lifecycle pattern is one of larval feeding and growth in autumn, winter, and spring, with adult emergence between late spring and early fall, although the adult activity of a few species peaks in the winter. Larvae are active in very cold water and can frequently be observed feeding under ice. In common with many aquatic insect species, many caddisfly adults emerge synchronously en masse. Such emergence patterns ensure that most caddisflies will encounter a member of the opposite sex in a timely fashion. Mass emergences of this nature are called 'hatches' by salmon and trout anglers, and salmonid fish species will frequently 'switch' to whatever species is emerging on a particular day. Anglers take advantage of this behavior by matching their artificial flies to the appropriate fly.

SPIDER

                                                                                                                                     SPIDER                                                                                                                                                                                                                                                                             Spiders (order Araneae) are air-breathing arthropods that have eight legs and chelicerae with fangs that
inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other orders of organisms.Spiders are found worldwide on every continent except for Antarctica, and have become established in nearly every habitat with the exceptions of air and sea colonization. As of 2008, at least 43,678 spider species, and 109 families have been recorded by taxonomists; however, there has been dissension within the scientific community as to how all these families should be classified, as evidenced by the over 20 different classifications that have been proposed since 1900.

Anatomically, spiders differ from other arthropods in that the usual body segments are fused into two tagmata, the cephalothorax and abdomen, and joined by a small, cylindrical pedicel. Unlike insects, spiders do not have antennae. In all except the most primitive group, the Mesothelae, spiders have the most centralized nervous systems of all arthropods, as all their ganglia are fused into one mass in the cephalothorax. Unlike most arthropods, spiders have no extensor muscles in their limbs and instead extend them by hydraulic pressure.

Anatomically, spiders differ from other arthropods in that the usual body segments are fused into two tagmata, the cephalothorax and abdomen, and joined by a small, cylindrical pedicel. Unlike insects, spiders do not have antennae. In all except the most primitive group, the Mesothelae, spiders have the most centralized nervous systems of all arthropods, as all their ganglia are fused into one mass in the cephalothorax. Unlike most arthropods, spiders have no extensor muscles in their limbs and instead extend them by hydraulic pressure.

Their abdomens bear appendages that have been modified into spinnerets that extrude silk from up to six types of silk glands within their abdomen. Spider webs vary widely in size, shape and the amount of sticky thread used. It now appears that the spiral orb web may be one of the earliest forms, and spiders that produce tangled cobwebs are more abundant and diverse than orb-web spiders. Spider-like arachnids with silk-producing spigots appeared in the Devonian period about 386 million years ago, but these animals apparently lacked spinnerets. True spiders have been found in Carboniferous rocks from 318 to 299 million years ago, and are very similar to the most primitive surviving order, the Mesothelae. The main groups of modern spiders, Mygalomorphae and Arane
omorphae, first appeared in the Triassic period, before 200 million years ago.

Circulation and respiration

 Like other arthropods, spiders are coelomates in which the coelom is reduced to small areas round the reproductive and excretory systems. Its place is largely taken by a hemocoel, a cavity that runs most of the length of the body and through which blood flows. The heart is a tube in the upper part of the body, with a few ostia that act as non-return valves allowing blood to enter the heart from the hemocoel but prevent it from leaving before it reaches the front end.However, in spiders it occupies only the upper part of the abdomen, and blood is discharged into the hemocoel by one artery that opens at the rear end of the abdomen and by branching arteries that pass through the pedicle and open into several parts of the cephalothorax. Hence spiders have open circulatory systems.The blood of many spiders that have book lungs contains the respiratory pigment hemocyanin to make oxygen transport more efficient.

Spiders have developed several different respiratory anatomies, based on book lungs, a tracheal system, or both. Mygalomorph and Mesothelae spiders have two pairs of book lungs filled with haemolymph, where openings on the ventral surface of the abdomen allow air to enter and diffuse oxygen. This is also the case for some basal araneomorph spiders like the family Hypochilidae, but the remaining members of this group have just the anterior pair of book lungs intact while the posterior pair of breathing organs are partly or fully modified into tracheae, through which oxygen is diffused into the haemolymph or directly to the tissue and organs.The trachea system has most likely evolved in small ancestors to help resist desiccation. The trachea were originally connected to the surroundings through a pair of openings called spiracles, but in the majority of spiders this pair of spiracles has fused into a single one in the middle, and moved backwards close to the spinnerets.Spiders that have tracheae generally have higher metabolic rates and better water conservation. Spiders are ectotherms, so environmental temperatures affect their activity.

The basic arthropod central nervous system consists of a pair of nerve cords running below the gut, with paired ganglia as local control centers in all segments; a brain formed by fusion of the ganglia for the head segments ahead of and behind the mouth, so that the esophagus is encircled by this conglomeration of ganglia. Except for the primitive Mesothelae, of which the Liphistiidae are the sole surviving family, spiders have the much more centralized nervous system that is typical of arachnids: all the ganglia of all segments behind the esophagus are fused, so that the cephalothorax is largely filled with nervous tissue and there are no ganglia in the abdomen in the Mesothelae, the ganglia of the abdomen and the rear part of the cephalothorax remain unfused.

COCKROCH

                                                                                         COCKROCH                                                                                                                                                                                                                                                            THE best-known pest species are the American cockroach, Periplaneta Americana, which is about 30 mm (1.2 in) long; the German cockroach, Blattella germanica, about 15 mm (0.59 in) long; the Asian cockroach, Blattella asahinai, also about 15 mm (0.59 in) in length; and the Oriental cockroach, Blatta orientalis, about 25 mm (0.98 in). Tropical cockroaches are often much bigger, and, contrary to popular opinion, extinct cockroach relatives and 'roachoids' such as the Carboniferous Archimylacris and the Permian Apthoroblattina were not as large as the biggest modern species.

Etymology
The name "cockroach" comes from the Spanish word for cockroach, cucaracha, transformed by English folk etymology into "cock" and "roach". The term cucaracha (streak bug, sp.) originally was used for the wood louse (the sow bug), but later was used to mean the palmetto bug (the flying cockroach). It is from this later Mexican usage that English-speaking Americans began using the term for regular (non-flying) cockroach.The scientific name derives from the Latinized Greek name for the insect (Doric Greek:  blátta; Ionic and Attic Greek:

Evolutionary history and relationships

A 40- to 50-million-year-old cockroach in Baltic amber

Evolutionary Relationships of Blattodea (cockroaches and termites) from Eggleton, Beccaloni & Inward (2007).The cockroach families Lamproblattidae and Tryonicidae are not shown but are placed within the superfamily Blattoidea. The cockroach families Corydiidae and Ectobiidae were previously known as the Polyphagidae and Blattellidae (see Beccaloni & Eggleton, 2011
Termites were previously regarded as a separate order Isoptera to cockroaches. However recent genetic evidence strongly suggests that they evolved directly from 'true' cockroaches, and many authors now place them as an "epifamily" of Blattodea. Blattodeans (cockroaches and termites) and Mantodea (praying mantises) are closely related and are combined by entomologists into a superorder called Dictyoptera.

Historically, the name Blattaria has been used largely interchangeably with the name Blattodea, but whilst the former name was used to refer to 'true' cockroaches exclusively, the latter also includes the termites. The current catalogue of world cockroach species (the Cockroach Species File Online uses the name Blattodea for the group. Another name, Blattoptera is also sometimes used for this group. The earliest cockroach-like fossils ("blattopterans" or "roachids") are from the Carboniferous period 354–295 million years ago. However, these fossils differ from modern cockroaches in having long external ovipositors and are the ancestors of mantises, as well as modern blattodeans. The first fossils of modern cockroaches with internal ovipositors appeared in the early Cretaceous.

Description                     
                              

Head of a Periplaneta americana Cockroaches are generally rather large insects. Most species are about the size of a thumbnail, but several species are bigger. The world's heaviest cockroach is the Australian giant burrowing cockroach Macropanesthia rhinoceros, which can reach 9 cm (3.5 in) in length and weigh more than 30 g (1.1 oz). Comparable in size is the Central American giant cockroach Blaberus giganteus, which grows to a similar length but is not as heavy. According to the Guinness World Records, the longest cockroach species is Megaloblatta longipennis, which can reach 97 mm (3.8 in) in length and 45 mm (1.8 in) across.[16] A Central and South American species, Megaloblatta blaberoides, has the largest wingspan of up to 185 mm (7.3 in).

Cockroaches have broad, flattened bodies and relatively small heads. They are generalized insects, with few special adaptations, and may be among the most primitive living neopteran insects. The mouthparts are on the underside of the head and include generalised chewing mandibles. They have large compound eyes, two ocelli, and long, flexible, antennae.

The first pair of wings (the tegmina) are tough and protective, lying as a shield on top of the membranous hind wings. All four wings have branching longitudinal veins, and multiple cross-veins. The legs are sturdy, with large coxae and five claws each. The abdomen has ten segments and several cerci.

CADDIS FLY

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                                                                                      CADDIS FLY                                                                                                                                                                                                                                                                                                                                                  The caddisflies are an order, Trichoptera, of insects with approximately 12,000 described species. Also called sedge-flies or rail-flies, they are small moth-like insects having two pairs of hairy membranous wings. They are closely related to Lepidoptera (moths and butterflies) which have scales on their wings, and the two orders together form the superorder Amphiesmenoptera. Caddisflies have aquatic larvae and are found in a wide variety of habitats such as streams, rivers, lakes, ponds, spring seeps, and temporary waters (vernal pools). The larvae of many species use silk to make protective cases of gravel, sand, twigs or other debris. The name "Trichoptera" comes from Greek.

Ecology
Although caddisflies may be found in waterbodies of varying qualities, species-rich caddisfly assemblages are generally thought to indicate clean water. Together with stoneflies and mayflies, caddisflies feature importantly in bioassessment surveys of streams and other water bodies. Caddisfly species can be found in all feeding guilds in stream habitats, with some species being predators, leaf shredders, algal grazers, and collectors of particles from the watercolumn and benthos.
Most caddisfly larvae are underwater architects and use silk, excreted from salivary glands near their mouths, for building. Caddisflies can be divided loosely into three behavioral groups based on their use of silk: net-making caddisflies and case-making caddisflies, both of which may enlarge their structures throughout their larval lifespan; and free-living caddisflies, which only make such structures prior to pupation. Net-
making caddisflies usually live in running water, and their nets, often made amongst aquatic vegetation, serve both as a means to collect algae, detritus, and animal food and as retreats. Case-making caddis flies may build cases exclusively of silk, but more commonly the silk holds together substrate materials such as small fragments of rock, sand, small pieces of twig or aquatic plants. Caddisfly cases are open at both ends, the larva drawing oxygenated water through the posterior end, over their gills, and out of the wider anterior end. The anterior end is usually wider and it is to this end that they add material as they grow. Their abdomens are soft, but their tougher front ends project from their larval tubes, allowing them to walk while dragging their cases along with them. Caddisfly cases resemble bagworm cases, which are constructed by various terrestrial moth species. Free-living caddisflies do not build retreats or carry portable cases until they are ready to pupate, and their bodies tend to be tougher than the building.

Development
Many species of caddisfly larvae enter a stage of inactivity called the pupa stage for weeks or months after they mature but prior to emergence. Their emergence is then triggered by cooling water temperatures in the fall, effectively synchronizing the adult activity to make mate-finding easier. In the Northwestern US, caddisfly larvae within their gravel cases are called 'periwinkles.
Caddisfly pupation occurs much like pupation of Lepidoptera. That is, caddisflies pupate in a cocoon spun from silk. Caddisflies that build the portable cases attach their case to some underwater object, seal the front and back apertures against predation though still allowing water flow, and pupate within it. Once fully developed, most pupal caddisflies cut through their cases with a special pair of mandibles, swim up to the water surface, cast off skin and the now-obsolete gills and mandibles, and emerge as fully formed adults. In a minority of species, the pupae swim to shore -- either below the water or across the surface -- and crawl out to emerge. Many of them are able to fly immediately after breaking from their pupal skin.
The adult stage of caddisflies, in most cases, is very short-lived, usually only 1–2 weeks, but can sometimes last for 2 months. Most adults are non-feeding and are equipped mainly to mate. Once mated, the female caddisfly will often lay eggs (enclosed in a gelatinous mass) by attaching them above or below the water surface. Eggs hatch in as little as three weeks.
Caddisflies in most temperate areas complete their life cycles in a single year. The general temperate-zone lifecycle pattern is one of larval feeding and growth in autumn, winter, and spring, with adult emergence between late spring and early fall, although the adult activity of a few species peaks in the winter. Larvae are active in very cold water and can frequently be observed feeding under ice. In common with many aquatic insect species, many caddisfly adults emerge synchronously en masse. Such emergence patterns ensure that most caddisflies will encounter a member of the opposite sex in a timely fashion. Mass emergences of this nature are called 'hatches' by salmon and trout anglers, and salmonid fish species will frequently 'switch' to whatever species is emerging on a particular day. Anglers take advantage of this behavior by matching their artificial flies to the appropriate fly.

STICK INSECTS

                                                                                                                           STICK
INSECTS                                                                                                                                                                                                                                                                                                                                  Stick insects are insects in the order Phasmatodea (or Phasmida).

The whole order is camouflaged as either sticks or leaves. Leaf insects are generally the family Phylliidae. They are found in South and southeast Asia to New Zealand.Over 3,000 species have been described.The name Phasmatodea comes from Ancient Greek phasma, meaning an apparition or phantom.

Life habit

The order has a worldwide distribution, but most species are found in the tropics. These tropic species vary from stick like species to those resembling bark, leaves and even moss or lichen. The stick insect can sometimes reach over 13 inches (33 cm) long. The longest is Chan's megastick.

A few species, such as Carausius morosus, are even able to change their pigmentation to match their surroundings. Many species are wingless, or have reduced wings.

Phasmids are herbivorous, feeding mostly on the leaves of trees and shrubs(e.g. privet). Their eggs are usually camouflaged, resembling plant seeds, and may remain dormant for a full season or more before hatching. The nymphs are born already closely resembling the adults.

Behaviour

Stick insects make rhythmic, repetitive side-to-side movements. This is like vegetation moving in the wind.
Also, the swaying movements may help the insects see objects against the background. Rocking movements by these sedentary (sitting) insects may replace flying or running as way to define objects in the visual field.
Some species of phasmid are able to produce a defensive spray when threatened. The spray contains pungent-smelling volatile molecules which the insect gets from its food plant. The spray from one species, Megacrania nigrosulfurea, is even used as a treatment for skin infections by a tribe in Papua New Guinea by virtue of its antibacterial constituents.

Mating involves long pairings. A record among insects, the Indian stick insect Necroscia sparaxes was seen coupled for 79 days at a time. It is not uncommon for this species to assume the mating posture for days or weeks on end, and among some species (Diapheromera veliei Walsh and D. Covilleae), pairing has been seen to last three to 136 hours in captivity.Explanations for this behaviour range from males guarding their mates against other males, to the view that the pairings are a defensive alliance against predators.

MAY FLY

                                                                                                                    

         MAY FLY

                                                                                                                                                                                                                                                                    Mayflies or shadflies are insects belonging to the order Ephemeroptera (from the Greekephemeros = "short-lived" (literally "lasting a day" "daily" or "day-long"), and πτερόν, pteron = "wing", referring to the brief lifespan of adults). They have been placed into an ancient group of insects termed the Palaeoptera, which also contains dragonflies and damselflies. They are aquatic insects whose immature stage (called "naiad" or, colloquially, "nymph") usually lasts one year in fresh water. The adults are short-lived, from a few minutes to a few days, depending on the species. About 2,500 species are known worldwide, including about 630 species in North America.The naiads live primarily in streams under rocks, decaying vegetation, or in the sediment. Few species live in lakes, but they are among the most prolific. For example, the emergence of one species of Hexagenia was recorded on Doppler weather radar along the shores of Lake Erie.

Most species feed on algae or diatoms, but a few species are predatory. The naiad stage may last from several months to several years, with a number of moults along the way. Most mayfly naiads are distinctive in having seven pairs of gills on the dorsum of the abdomen. In addition, most possess three long cerci or tails at the end of their bodies. Some species, notably in the genus Epeorus, have only two tails. In the last aquatic stage, dark wingpads are visible. Developmentally, these insects are considered hemimetabolous. A more casual and familiar term is "incomplete metamorphosis". Mayflies are unique among insects in that they moult one more time after acquiring functional wings (this is also known as the alate stage); this last-but-one winged instar usually lives a very short time, often a matter of hours, and is known as a subimago or to fly fishermen as a dun. Mayflies in this stage are a favourite food of many fish, and many fishing flies are modelled to resemble them.

BEETLE

                 BEETLE                                                                                                                                                                                                         The Coleoptera  order of insects is commonly called beetles. The word "coleoptera" is from the Greek  koleos, meaning "sheath"; and  pteron, meaning "wing", thus "sheathed wing", because most beetles have two pairs of wings, the front pair, the "elytra", being hardened and thickened into a shell like protection for the rear pair and the beetle's abdomen. The superficial consistency of most beetles' morphology, in particular their possession of elytra, has long suggested that the Coleoptera are monophyletic, but growing evidence indicates this is unjustified, there being arguments for example, in favor of allocating the current suborder Adephaga their own order, or very likely even more than one.

Overview

The Coleoptera includes more species than any other order, constituting almost 25% of all known types of animal life-forms. About 40% of all described insect species are beetles (about 400,000 species and new species are discovered frequently. Some estimates put the total number of species, described and undescribed, at as high as 100 million, but a figure of one million is more widely accepted.The largest taxonomic family is commonly thought to be the Curculionidae (the weevils or snout beetles), but recently the Staphylinidae (the rove beetles) have claimed this title.[citation needed].

The diversity of beetles is very wide. They are found in all major habitats, except marine and the polar regions. They have many classes of ecological effects; particular species are adapted to practically every kind of diet. Some are nonspecialist detritus feeders, breaking down animal and plant debris; some feed on particular kinds of carrion such as flesh or hide; some feed on wastes such as dung; some feed on fungi, some on particular species of plants, others on a wide range of plants. Some are generalist pollen, flower and fruit eaters. Some are predatory, usually on other invertebrates; some are parasites or parasitoids. Many of the predatory species are important controls of agricultural pests. For example, beetles in the family Coccinellidae   aphids, scale insects, thrips, and other insects that damage crops.

                                    Conversely, beetles are prey of various invertebrates and vertebrates, including other insects, fish, reptiles, birds, and mammals. The Coleoptera are not generally serious pests, but they include agricultural and industrial pests, such as the Colorado potato beetle Leptinotarsa decemlineata, the boll weevil Anthonomus grandis, the red flour beetle Tribolium castaneum, and the mungbean or cowpea beetle Callosobruchus maculatus. Also included is the death-watch beetle, the larvae of which can cause serious structural damage to buildings by boring into the timbers.

INSECTS

                                                                                              INSECTS                                                                                                                                                                          Insect, common name given to any animal of a class belonging to the arthropod phylum. The insects are the largest class in the animal world, outnumbering all other animals. At least 800,000 species have been described, and entomologists believe that as many or more remain to be discovered. The class is distributed throughout the world from the polar regions to the tropics and is found on land, in fresh and salt water, and in salt lakes and hot springs. The insects reach their greatest number and variety, however, in the tropics. In size, the insects also exhibit great variation. Some small parasitic insects are less than 0.025 cm (less than 0.01 in) in length when fully grown, whereas at least one fossilized species related to the modern dragonflies is known to have had a wingspread of more than 60 cm (24 in). The largest insects today are certain stick insects about 30 cm (about 12 in) long and certain moths with wingspans of about 30 cm (about 12 in).

Insects also are the most highly developed class of invertebrate animals, with the exception of some mollusks. Insects such as the bees, ants, and termites have elaborate social structures in which the various forms of activity necessary for the feeding, shelter, and reproduction of the colony are divided among individuals especially adapted for the various activities. Also, most insects achieve maturity by metamorphosis rather than by direct growth. In most species, the individual passes through at least two distinct and dissimilar stages before reaching its adult form.

In their living and feeding habits, the insects exhibit extreme variations. Nowhere is this more apparent than in the life cycle of various species. Thus the so-called 17-year locust matures over a period of 13 to 17 years. The ordinary house fly can reach maturity in about ten days, and certain parasitic wasps reach their mature form seven days after the eggs have been laid. In general the insects are very precisely adapted to the environments in which they live, and many species depend on a single variety of plant, usually feeding on one specific portion of the plant such as the leaves, stem, flowers, or roots. The relationship between insect and plant is frequently a necessary one for the growth and reproduction of the plant, as with plants that depend on insects for pollination. A number of insect species do not feed on living plants but act as scavengers. Some of these species live on decaying vegetable matter and others on dung or the carcasses of animals. The activities of the scavenger insects hasten the decomposition of all kinds of dead organic material.

GRASS HOPPER

                                                                                               GRASS HOPPER                                                                                                                                                                                                                                                            The grasshopper is an insect of the suborder Caelifera in the order Orthoptera, sometimes referred to as the short-horned grasshopper to distinguish it from katydids, or bush crickets. Grasshopper species which change color and behavior at high population densities are called locusts.

Characteristics

They are easily confused with the other sub-order of Orthoptera, Ensifera (crickets), but are different in many aspects, such as the number of segments in their antennae and structure of the ovipositor, as well as the location of the tympana and modes of sound production. Ensiferans have antennae with at least 20–24 segments, and caeliferans have fewer. In evolutionary terms, the split between the Caelifera and the Ensifera is no more recent than the Permo-Triassic boundary (Zeuner 1939).^[2]Grasshoppers have antennae that are generally shorter than their body and short ovipositors. They also have pinchers or mandiblesthat cut and tear off food.^[1] Those species that make easily heard noises usually do so by rubbing the hind femurs against the forewings or abdomen (stridulation), or by snapping the wings in flight. Tympana, if present, are on the sides of the first abdominal segment. The hind femora are typically long and strong, fitted for leaping. Generally they are winged, but hind wings are membranous while front wings (tegmina) are coriaceous and not fit for flight. Females are normally larger than males, with short ovipositors. Males have a single unpaired plate at the end of the abdomen. Females have two pairs of valves (triangles) at the end of the abdomen used to dig in sand during egg laying.

As with insects and other organisms possessing open circulatory systems, most body cavities and appendages contain the blood-like substance hemolymph, which in grasshoppers tends to appear green-ish when exposed to open air^{[citation needed]}. The dorsal vessel is the exception to the grasshopper's open circulation and extends from the head through the thorax to the hind end. It is a continuous tube with two regions: the heart, which is restricted to the abdomen; and the aorta, which extends from the heart to the head through the thorax. Haemolymph is pumped forward from the hind end and the sides of the body through a series of valved chambers, each of which contains a pair of lateral openings (ostia). The haemolymph continues to the aorta and is discharged through the front of the head. Accessory pumps carry haemolymph through the wing veins and along the legs and antennae before it flows back to the abdomen. This haemolymph circulates nutrients through the body and carries metabolic wastes to the malphighian tubes to be excreted. Respiration is performed using, air-filled tubes, which open at the surfaces of the thorax and abdomen through pairs of spiracles. The spiracle valves only open to allow oxygen and carbon dioxide exchange. The tracheoles, found at the end of the tracheal tubes, are insinuated between cells and carry oxygen throughout the body. (For more information on respiration, see Insect.)

Nervous system

The grasshopper's nervous system is controlled by ganglia, loose groups of nerve cells which are found in most species more advanced than cnidarians. In grasshoppers, there are ganglia in each segment as well as a larger set in the head, which are considered the brain. There is also a neuropile in the usingtracheae, through which all ganglia channel signals. The sense organs (sensory neurons) are found near the exterior of the body and consist of tiny hairs (sensilla), which consist of one sense cell and one nerve fibre, which are each specially calibrated to respond to a certain stimulus. While the sensilla are found all over the body, they are most dense on the antennae, palps (part of the mouth), and cerci(near the posterior). Grasshoppers also have tympanal organs for sound reception. Both these and the sensilla are linked to the brain via the neuropile.

WASP

                                                                                              WASP                                                                                                                                                            A wasp is any insect of the order Hymenoptera and suborder Apocrita that is neither a bee nor an ant. Almost every pest insect species has at least one wasp species that preys upon it or parasitizes it, making wasps critically important in natural control of their numbers, or natural biocontrol. Parasitic wasps are increasingly used in agricultural pest control as they prey mostly on pest insects and have little impact on crops.The majority of wasp species (well over 100,000 species) are "parasitic" (technically known as parasitoids), and the ovipositor is used simply to lay eggs, often directly into the body of the host. The most familiar wasps belong to Aculeata, a "division" of Apocrita, whose ovipositors are adapted into a venomous sting, though many aculeate species do not sting. Aculeata also contains ants and bees, and many wasps are commonly mistaken for bees, and vice-versa. In a similar respect, insects called "velvet ants" (the family Mutillidae) are technically wasps.

The suborder Symphyta, known commonly as sawflies, differ from members of Apocrita by lacking a stinger and having a broader connection between the mesosoma and metasoma. In addition to this, Symphyta larvae are mostly herbivorous and "caterpillar-like", whereas those of Apocrita are largely predatory.

A much narrower and simpler but popular definition of the term wasp is any member of the aculeate family Vespidae, which includes (among others) the genera known in North America as yellow jackets (Vespula and Dolichovespula) and hornets (Vespa); in many countries outside of the Western Hemisphere, the vernacular usage of wasp is even further restricted to apply strictly to yellow jackets (e.g., the "common wasp")he various species of wasps fall into one of two main categories: solitary wasps and social wasps. Adult solitary wasps live and operate alone, and most do not construct nests (below); all adult solitary wasps are fertile. By contrast, social wasps exist in colonies numbering up to several thousand individuals and build nests but in some cases not all of the colony can reproduce. In some species, just the wasp queen and male wasps can mate, whilst the majority of the colony is made up of sterile female workers.
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