Insecta     Insects, insects everywhere although most people however only notice them when they bug them. They are generally considered a pest to be destroyed at any cost without appreciating their value. The world we know now would not exist without them. For instance flowering plants including many of our food crops depend on them for pollination. There are now one million insect species classified in the world but the true number can only be estimated ranging from ten to hundredfold. Especially in the tropics are they numerous and unfamiliar characteristics like large size, bright colors, cryptic shapes or strange behavior await the curious visitor in Ecuador.    The large and neotropical Morpho butterfly is famous for its brilliant blue coloration (right photo)They are most easily observed flying along smaller rivers overhung by thick vegetation. When resting they usually have their wings closed showing a dark coloration with eyespots (photo to left) on it.     Beetles are the world's most numerous insects and that holds also true in Ecuador. They can be found in all ecosystems feeding on vegetation, dung, carrion or preying on other insects. Not far behind in numbers are the colorful butterflies and their cousins, the cryptic nocturnal moths (although there are also colorful diurnal species). These insects are important flower pollinators using their long proboscis to probe for nectar. Not so easily seen are the walking sticks resembling parts of a branch. The praying mantis are ferocious predators grabbing other insects in rapid movements. Very interesting groups are the social insects, the ants, bees, wasps and termites. True bugs are somehow similar to beetles but have their own important characteristics and suck plant juices. Grasshoppers and crickets are often heard for their clicking sounds. A more rare group of insects are the lacewings and antlions, which have highly veined wings. Cicadas are noisy flying insects swarming around trees. Flies are well known and range from the house fly to mosquitoes, sometimes carriers of diseases. Other interesting insects not mentioned are dealt with in the Others chapter.   Insects and flowering plants benefit from each other and co-evolved together. Through this mutualism both diversified greatly in numbers. Flowers make up presently the majority of plants and insects are by far the largest group of animals either in species or individual numbers. This video of a small fly and a composite flower was taken at an altitude of 3600m at Pichincha volcano near Quito. In it you can surely appreciate this symbiotic relationship. As the fly feeds on the nutrient-rich pollen provided by the flower, it gets covered by it. It will then transport the yellow pollen to its next flower feeding station. Chances are good that one of those following flowers will get fertilized and start to set seed.      Insects play an important role in any ecosystem and without them "higher" animals would not be able to survive. Flowering plants depend for them for pollination. The most important pollinators are the bees followed by beetles and flies. Other insects help in recycling nutrients by feeding on dead organic matter. From the human perspective there are also harmful insects. Some destroy crops by eating leaves or roots and sucking sap. Billions are spent on pesticides to control them. Others like flies and fleas carry diseases and millions of people get infected worldwide each year.    Another insect family associated with the hot tropics are the walking sticks or stick insects, scientifically known as Phasmida. Although much more abundant in the lower tropical regions like the male stick insect, Orephoetes peruana to the left, they also can be found in high altitudes of some 4000m like the one shown below called Monticomorpha flavolimbata. They are especially plentiful in the paramo regions around Cotopaxi, inhabitating rock crevices and hollow skulls of dead animals.

Natural History Insects were among the first animals to inhabit dry land. The earliest fossil of an insect dates back to the Devonian era, some 400 million years ago. They started to diversify taking advantage of the extensive vegetation of the following geological eras. They were also the first group of animals to take to flight, long before any other animal group hit on that evolutionary advantage. At that time flying insects were considerable larger than today (fossils of dragonflies 4 times the size of present species are known). The probable cause for that was a more oxygen rich atmosphere and no aerial predators. The real explosion in insect diversity however occurred some 130 million years ago with the emergence of flowering plants. Both co-evolved together helping each other cause. Flowers provide insects with rich food and get paid back by efficient pollination. Today they comprise by far the biggest group of animals with over 1 million species classified worldwide. Estimates of their real numbers however range from 10 to 100 million more species. In numbers, total mass or distribution they are the most successful animals nowadays and animal diversity is basically insect diversity.      Classification Insects belong to the class of Insecta which is part of the phylum Arthropoda, a major animal phylum which comprises those invertebrates, which have an external skeleton and jointed appendages (in contrast to the vertebrates, which are animals with a backbone). Other arthropods are the arachnids (spiders, scorpions & ticks) and crustaceans (shrimps, crabs,  etc..).   Note: Classifications change over the years and no definite one is established yet. Below is an older traditional scheme which will serve us well.    Orders of Insects   Apterygota - wingless insects Protura telson tails Thysanura silverfish Diplura japygids Collembola springtail   Pterygota - winged insects Ephemeroptera mayflies Plecoptera stoneflies Odonata dragonflies, damselflies Grylloblattodea cricket-cockroaches Orthoptera crickets, grasshoppers Phasmida walkingsticks Thysanoptera thrips Dermaptera earwigs Plecoptera stonewalls Dictyoptera mantids, cockroaches Mallophaga biting lice Isoptera termites Embioptera web-spinners Psocoptera book lice, bark lice Phthiraptera bird lice, true lice Zoraptera angel wings Megaloptera alderflies, dobsonflies Raphidiodea snake flies Neuroptera antlions, lacewings Mecoptera scorpion flies Trichoptera caddies flies Lepidoptera butterflies, moths Diptera true flies, mosquitoes Siphonaptera fleas Coleoptera beetles, fireflies, weevils Strepsiptera stylopids Hymenoptera ants, bees, wasps, hornets Hemiptera true bugs Homoptera aphids, cicadas, leafhoppers Anoplura sucking lice      Biologically Speaking Insects are small animals with a segmented body comprising of three parts, the head, thorax and abdomen. Most of 3 pairs of legs, a pair of antennae and 2 pairs of wings. Arthropods developed from soft bodied annelid-kind animals but developed later an external skeleton or cuticle for protection. That skeleton however limits the size of those animals and has to be shed occasionally for growth reasons and then the animals are vulnerable. The senses of insects are quite different to those of vertebrates. Antennae function as taste and touch organs and eyes are simple or compound ones and come in pairs or multiples. Another very distinct trait is that of metamorphosis. The young or larva differs greatly from an adult or imago in physical form and behavior. Different insect families undergo distinct metamorphosis, from complete ones like in butterflies to shortened or incomplete ones.