What are beetles? |
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by Dr. Lawrence Kaplan. Source : http://www.coleoptera.org/p1058.htm |
Beetles or Coleoptera are one of approximately 30 orders of the class of Insecta. The Order of Coleoptera is in many respects sharply distinguished from other insects and is the favourite subject of study of both, professional scientists and naturalists. The beetles are the largest order including more species known to science than any other order not only in the Class of Insecta, but also in the entire animal kingdom (Animalia). The most authoritative calculations indicate that already now more than 350,000 species of beetles have been described. Every year approximately 2000 new species are described (Zoological Record). Taking into account that the entire fauna of the earth is considered to include approximately 1,400,000 species it can be stated that beetles constitute more than a quarter of all known animals. Moreover, recent attempts of total collections of insects from several species of tropical trees in the basin of the Amazon River have shown that 50% of beetles found by this method are new (Erwin, 1982; 1997). Faunae from different species of trees are so very different from one another that it is possible to predict discovery of several hundreds of thousands or even millions of beetle species and according to some evaluations up to 7 million species. Beetles are most abundant in the tropics; but at the same time they have got adapted to life at all latitudes and in nearly every habitat, to feeding on any substances of organic origin. Therefore, beetles are nearly ubiquitous. They have not been found on the Antarctic Continent yet, but inhabit the subantarctic islands, they have not been found in the open sea, but are abundant on sea coasts, they have not been found beyond the boundary of eternal snows, but very interesting species of beetles occur high in the mountains in the summer immediately close to this boundary. Many species of beetles attain large numbers. The above explains why the beetles are so well known. Beetles, as well as cats, dogs and birds are the first animals that a small child who begins to talk, learns to recognize. Beetles are extremely diverse not only in size and colour, but also in body shape, sculpture of external cover, presence of various outgrowths, etc. Butterflies probably excel beetles in the splendour of colours, however, beetles have no match in the fantastic diversity of forms. Therefore beetles are an inexhaustible source of inspiration for writers, sculptors, artists, ornamenters and pattern-designers. Perhaps for this reason and also due to the extreme simplicity of storage of dead specimens beetles are a favourite object of collecting. Many species of beetles are serious pests of agriculture and forestry, stored food, wood, leathers, furs, fabric. Other species, vice versa, are disturbed as a result of man's economic activity; they are permanently declining in numbers or become extinct. Some common species of beetles respond sensitively to the state of natural environment and may serve as convenient indicators of anthropogenic pollution. Therefore, knowledge of beetles is indispensable not only to professional zoologists, but also to plant protection specialists, agriculturists, arboriculturists, museum specialists and workers of food processing industry, ecologists, staff of reserves and specialists in many other areas. All insects are studied by a special field of zoology - entomology. The study of beetles in its turn has long ago become a separate branch of entomology, coleopterology. Accordingly, specialists studying beetles are called coleopterists. At the Zoological Institute of the Russian Academy of Sciences (hereinafter referred to as ZIN) coleopterology has long and famous traditions. Coleopterological study conducted at ZIN is based upon the Institute's collection containing now not less than 6 million of specimens. The collection was started as early as 1714 by Peter the Great when the Kunstkammer was established. A jump in the development of study of beetles is associated with to the name of E. Menetries, a world-famous entomologist . After him a series of prominent coleopterists including A.F. Moravitz, A.P. Semenov-Tian-Shansky, G.G. Jacobson, A.N. Reichardt, A.A. Richter, E.L. Gurjeva, M.E. Ter-Minasian, and O.L. Kryzhanovsky worked at ZIN. Source : http://www.zin.ru/ANIMALIA/COLEOPTERA/eng/intro.htm |
Beetle ( Coleoptera )
Classification Of Bugs
Class | Main Body Region | Pairs Of Legs | Pairs Of Antenna | Wings |
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Crustacea | two - cephalothorax* and abdomen (some with head and trunk | five or more | two | absent |
Myriaopoda | two - head and trunk | many - one or two per trunk segment | one | absent |
Arachnid | two - cephalothorax* and abdomen | four | none (though palps may resemble antennae or legs) | absent |
Insecta | three - head, thorax and abdomen | three | one | usually present (but many wingless form) |
Each of the Classes of arthropods, including the insects are split into a number of smaller groups, which reflect progressively more detailed structural similarities between the group member. These smaller groups follow a strict hierarchy. The major class division in descending order of size are called Subclass, Order, Suborder, Family, Subfamily and Genus. A Genus is the smallest group of any real importance in the naming of individual species, although in some classifications generic groups may be further spllit into Subgenera. The scientific name of a species includes, first, the Genus to which it belongs and, second, its specific name, e.g. the European Violet Ground Beetle is called Carabus violaceus, meaning the species violaceus in the Genus Carabus (by convention, generic and specific names are always printed in italics; the generic name spelt with a capital letter and the specific name with a smaller letter). The full classification of insect would be as follow :
PHYLUM : | Arthropoda | arthropod |
CLASS : | Insecta | insect |
SUBCLASS : | Pterygota | winged insect |
ORDER : | Coleoptera | beetle |
SUBORDER : | Adephaga | carnivorous beetle |
FAMILY : | Carabidae | ground beetle |
SUBFAMILY : | Carabinae | - |
GENUS : | Carabus | - |
SPECIES : | Carabus violaceus L. | violet ground beetle |
ORDER | COMMON NAME |
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1. Branchiopoda | Water Fleas (Daphnia), Fairy, Brine, Tadpole, and Clam Shrimps |
2. Copepoda | Water Fleas (Cyclops), Fish Lice, Gill Maggots and Anchor Worms |
3. Ostracoda | Seed Shrimps |
4. Cirrepedia | Barnacles |
5. Stomatopoda | Mantis Shrimps |
6. Mysidacea | Opossum Shrimps |
7. Decapoda | Shrimps, Prawns, Lobsters, Crayfish and Crabs |
8. Amphipoda | Freshwater Shrimps (Gammarus) and Sand Hoppers |
9. Isopoda | Sea Slatters, Water Slatters, Water Lice and Hog Lice |
Isopoda: Oniscoidea (part) | Woodlice |
Class Myriapoda
ORDER | COMMON NAME |
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1. Pauropoda | - |
2. Symphylia | - |
3. Diplopoda | Millipedes |
4. Chilopoda | - |
Class Arachnid
ORDER | COMMON NAME |
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1. Xiphosura | King Crabs or Horseshoe Crabs |
2. Pseudoscorpiones (=Chernetidae) | Pseudoscorpions or False Scorpions |
3. Scorpionidae | Scorpions |
4. Pedipalpi | Whip Scorpions |
5. Solifuga (=Solpugae) | Wind Scorpions or Barrel Spiders |
6. Opiliones (=Phalangidae) | Harvestmen or Harvest Spiders |
7. Acari (=Acarina) | Mites and Ticks |
8. Araneae | True Spiders |
ORDER | COMMON NAME | SUBCLASSES & FEATURES |
1. Thysanura | Bristletails | APTERYGOTA These are wingless insects and their body structure suggests that they never had wings during their evolutionary history. Young stages resemble the adults – little or no metamorphosis |
2. Diplura | Two-pronged Bristletails | |
3. Protura | - | |
4. Collembola | Springtails | |
5. Ephemeroptera | Mayflies | PTERYGOTA Division EXOPTERYGOTA These are winged insects, although some have lost their wings during the course of evolution. When present, the wing develop externally and there is no marked change (metamorphosis) during the life cycle. The young stages, called nymph, resemble the adult except in seze and in lacking fully-developed wings – simply metamorphosis. |
6. Odonata | Dragonflies | |
7. Plecoptera | Stoneflies | |
8. Grylloblattodea | - | |
9. Orthroptera | Crickets, Grasshoppers and Locusts | |
10. Phasmida | Stick and Leaf Insects | |
11. Dermaptera | Earwings | |
12. Embioptera | Web-spinners | |
13. Dictyoptera | Cockroaches and Mantids | |
14. Isoptera | Termites | |
15. Zoraptera | - | |
16. Psocoptera | Psocids and Booklice | |
17. Mallophaga | Biting Lice | |
18. Siphunculata (=Anoplura) | Sucking Lice | |
19. Hemiptera | True Bugs | |
20. Thysanoptera | Thrips | |
21. Neuroptera | Alder Flies, Snake Flies and Lacewings | PTERYGOTA Division ENDOPTERYGOTA These are winged insects, although some have lost their wings during the course of evolution. When present, the wings develop internally (i.e. inside the body of the immature insect) and there is a marked change (metamorphosis) during the life cycle. The young stages are very different from the adults and are called larvae. The change from larva to adult takes place during a non-feeding stage called the pupa (or chrysalis) – complex metamorphosis. |
22. Coleoptera | Beetles | |
23. Strepsiptera | Stylopids | |
24. Mecoptera | Scorpion Flies | |
25. Shiponaptera | Flea | |
26. Diptera | True Flies | |
27. Lepidoptera | Butterflies and Moths | |
28. Tricoptera | Caddis Flies | |
29. Hymenoptera | Bees, Wasps and Ants |
Thanks to Dr David Kendall BSc PhD
Mayfly
If there is one aquatic insect that is always associated with the art of Fly Fishing, then the May Fly is that insect. This insect has been referred to as the very foundation of the sport. Since the year 1496, the Mayfly has been known to have a great influence for the angler. Dame Julianna Burners of England described the dressings for a dozen imitations that are known to catch fish. The journal that contained this information was called Treatys of Fyshing with an Angle. In the 1600s both Issac Walton and Charles Cotton wrote on the subject and started a splurge of writings promoting the use of Mayfly imitations and this insect became the symbol associated with the art of fly-fishing. Whether you are watching a film, video, movie or reading a book, magazine, or article on Fly Fishing you will be told that the May Fly is the Holy Grail insect. There are 16 Families, 47 different Genera and over 500 North American species of this important insect but only a very small portion is of importance to the fly angler. In Maine there are over 142 species.
All aquatic insects are under a constant attack from insect predators such as; their own kind, diving beetles, salamanders, frogs, back swimmers, birds and of course the fish.
These insects have a technical name, (Ephemeridae), which translates into the phase, "lives but a day." These insects emerge from their underwater world without mouthparts and therefore can't eat. Now, you know why they live only but a day.
Another common name is Ephemeroptera, which translates to mean upturned wing.
The four stages of a Mayflies life cycle are; egg (Ovum, 1 to 3 weeks), Nymph (Nymphal 11 months to 24 months with 20-30 Moults), Dun (Sub-imago 1 to 4 days) and Spinner (Imago about 1 day).
Egg
The eggs of the insect are deposited on or in water differently depending on the species. In some species the female will skim across the surface of the water in order to dislodge the eggs from her abdomen. Another species will fly across the waters surface and drop yellow or orange egg masses onto the waters surface. Some female mayflies will even use a protruding stem, leaf or other organic structure to crawl into the water in order to safely deposit her eggs at the bottom of the water column and others will actually dive into the waters surface in order to break the surface tension, then release the eggs underwater. Once the egg lying has taken place the exhausted insect will often times fall onto the surface of the water only to be taken by fish that have observed it from below the waters surface.
Nymph
After time, which in some species can be as little as a few hours and in others the time can be several months, these eggs will hatch and an immature nymph will then crawl under the stones of a riffle or the medium to large rocks or boulder of a run, burrow into the silt or muddy area of the slower currents of pools or the nymph may cling to the under sides of submerged vegetation or the branches of a fallen tree along the banks or shoreline. There are even some species that will be free-swimming aquatic insects that will swim around areas of aquatic vegetation and/or any structure that has been created by fallen shoreline or banking debris. Most of the Mayfly Species have three tails but there are some that only have two. These tails are visible throughout most of the developmental stages. All will have six legs with one sharp claw on each foot. In the adult the tail can be as long as the insect itself. There are generally 10 abdominal segments with moving gills along the sides of the insect.
The crawlers are variable in size and generally inhabit areas of medium and slower currents; they consist of the prolific Ephemerellidae family, the weak-legged Leptophlebiidae family and the very small insects of the Tricorythidae and Caenidae families.
The clingers are of the fast-water Heptageniidae family and the very large Baetidae family is made up of fast swimmers, while the burrowing types are of the families Ephemeridae, Potamanthidae and Polymitarcyidae.
This process of aquatic insects rising towards the surface is called an Emergence. Yes, I know that everyone refers to this event as a Hatch but you know the truth and that is that nymphs hatch from eggs and emerge from the water as duns. Every species has its' own emerging characteristics and time table. As the insects rise toward the surface, they become very vulnerable and fish will feed readily on them. During this emergence, fish will become very selective to the physical size, color, shape and actions of the emerging species.
Once on the surface the newly emerged Mayflies will either remain in the waters current or attach itself to a partially submerged limb or rock in order to then separate themselves from their skins or shucks - or more appropriately called exoskeleton, spread their wings, pump fluid into the veins causing the wing to strengthen in order to support flight. The Mayfly will float on the surface of the water, like little sailboats, with its newly inflated wings acting as sails being dried and blown around by the wind. This surface activity can last for only a few seconds to only a few minutes. Once the wings are dry enough and strong enough the insect will take flight. After taking flight, the sub-imago usually rests on the shoreline vegetation for 1 or 2 hours or 1 or 2 days depending on the species, while gradually going through the last molt and transforming from sub-imago into adult (imago or spinner).
Adult Mayfly
This adult Mayfly has no functioning mouth and therefore can't eat, and now you know why they, "live but a day." These Mayflies can emerge like this by the thousands and is an experience that will be remembered by any angler encountering it for the first time. These mass emergent patterns are the Mayflies main defense against its natural predators, among them being fish and birds. They will hatch in such great numbers, condensed in both time and location, that the before mentioned predators are unable to rally their troops for a mass consumption.
The sexually mature adult male spinner will mass in swarms over the waters surface. The characteristics and timing of the nuptial flight or mating swarm will vary from species to species. Once the selection and the mating activities have occurred the male will shortly die and the female will wait for low light conditions before depositing her eggs, then she too will die and fall to the surface of the water only to be consumed by a waiting fish. The dead or dying adults will then lie on the waters surface with wings spread and, at that point, is referred to as 'spent' spinners.
Dragonfly Life Cycle
Mating
Larva (Nymph / Naiad)
Bug - Lucanus Cervus
Identification
At an impressive and conspicuous five centimetres in length from tip of mandible to tip of abdomen, male specimens of this dark brown and black beetle have been recorded as the largest native terrestrial beetle found in Great Britain. They grow to about 8cm, but usually about 5 cm. Physical size and the magnificently antlered mandibles are therefore a good guide to the identification of this species when specimens are of this gender, although the female is only around three and a half centimetres in length with much smaller mandibles.
The size of both sexes varies considerably, such variety amongst other wood-boring insects being normal due to differences in the nutritive properties of the various trees upon which larvae feed (Imms, 1971).
Eggs
12 to 24 laid in next to rotting wood. The female may take a long time carefully preparing her nursery, digging around, chewing pieces of wood, and compacting them near the dead wood. As each egg is laid she uses her retractable ovipositor to form a hollow around it, exactly like some dung and burying beetles do.
Larva
Stag Beetle larvae are blind and shaped like a letter "C". They feed on rotting wood in a variety of places, tree stumps, old trees and shrubs, rotting fence posts, compost heaps and leaf mould. The larvae have a cream coloured soft transparent body with six orange legs, and an orange head which is very distinct from the very sharp brown pincers. They have combs in their legs which they use for communication (stridulation) with other larvae.
Instar
The stage in an insect's life history between two moults. When a stag beetle larva first comes out of the egg it is in his first instar (L1). This tiny freshly hatched larva has a rigid head so, in order to grow, it has to shed its skin by moulting. This way the second instar (L2) is the larva after the first moult; the third instar (L3) is the larva after the second moult.Usually stag beetle larvae are expected to reach their third instar before the start of their first winter, and after that will spend a long time fattning up before they are ready to pupate. Very interestingly it was found that with stag beetles reared in captivity a fifth or even a sixth instar might happen
Picture shows the third instar
weight - 21.5 g , length - 8 cm
Between three and six weeks during the summer inside a cocoon, in the soil, made of compacted soil. In the wild prepupation gets well under way before the end of July.
female stag beetle pupa
Adult stag beetle
The adult stab beetle may stay inside the cocoon or not. In any case it will always remain under the ground for several months until it emerges in the summer to fly outside.
source : www.biodiversitysussex.org , www.websters-online-dictionary.org , maria.fremlin.de