The race to create 'insect cyborgs'
Insects outweigh all the fish in the oceans and all the livestock munching grass on land. Their abundance, variety there could be as many as 30 million species , and ubiquity mean insects play a foundational role in food webs and ecosystems: from the bees that pollinate the flowers of food crops like almonds to the termites that recycle dead trees in forests. In all, the researchers conclude that as much as 40 percent of all insect species may be endangered over the next several decades.
And around 41 percent of all insect species on record have seen population declines in the past decade. Most of the data was obtained from studies conducted in Europe and North America. A true, global assessment might tell a different story. The trouble with this method is that it biases the analysis toward declines, and excludes gains or stable populations.
Given their limited research methods, this might be a premature conclusion. But there are reasons to be worried about insects, particularly vulnerable orders, like butterflies. And human activity is hugely to blame. Butterflies and moths, known as the Lepidoptera order, are some of the hardest hit: 53 percent of Lepidoptera have seen declining population numbers, a ccording to the new survey.
This is especially concerning as butterflies, which are very sensitive to changes in landscape and food sources, are often a bellwether of environmental health. Some 50 percent of Orthoptera species grasshoppers and crickets, another important source of food for an enormous array of animals are also in decline.
Forty percent of bee species are listed as vulnerable for extinction, and most dung beetle species named for — you guessed it — what they like to eat are vulnerable or endangered. A study in Germany noted a 75 percent decline in flying insects over three decades. A specialist is an organism that occupies a tiny niche in an ecosystem like a moth that only feeds on one particular plant.
A generalist, on the other hand, is more adaptable and can more easily change environments and food sources.
Both types of insects are facing major losses. In October, a study in Proceedings of the National Academy of Science documented that between and , the number of invertebrates like insects, spiders, and centipedes in the Luquillo rainforest in Puerto Rico caught in survey nets plummeted by a factor of four or eight. When measured by the number caught in sticky traps, invertebrates declined by a factor of And that loss of insects coincided with losses of birds, lizards, and frogs.
The researchers in the new Biological Conservation paper outline four broad, global problems leading to insect loss. Pesticide use needs to decline drastically as well. Chlorophyta Streptophyta Chlorokybophyceae Mesostigmatophyceae Spirotaenia. Ancoracysta twista Haptista Centroheliozoa Haptophyta. Ciliates Miozoa Acavomonadia Colponemidia Myzozoa. Ancyromonadida Malawimonadea Metamonada Anaeromonada , Trichozoa.
Maria Sibylla Merian
Cristidiscoidea Zoosporia Opisthosporidia True fungi. Ichthyosporea Pluriformea Syssomonas Corallochytrea. Choanoflagellates Filasterea Metazoa or Animals. Major kingdoms are underlined. Organism Eukaryota flora plants fauna animals fungi protista Prokaryotes archaea bacteria Viruses. Animals portal Biology portal. Retrieved from " https: Animals Kingdoms biology Cryogenian first appearances. Views Read View source View history. This page was last edited on 3 December , at Insect respiration happens without lungs.
There is a system of internal tubes and sacs through which gases diffuse or are actively pumped. Air is taken in through openings on the sides of the abdomen called spiracles. Oxygen gets to tissues that need it through their trachea element 8 in diagram. Many insect larva e live in water. Many of those have gills that can extract oxygen dissolved in water.
Others must rise to the water surface to get air which may be held or trapped in special parts of their body. Adult insects use oxygen at a high rate when they fly. They need it for the flight muscles, the most active tissue known in biology. The largest insect bodies are about as big as a mouse.
The use of insects in forensic investigations: An overview on the scope of forensic entomology
Some insects also use a molecule called haemocyanin , which does the same job as haemoglobin does in vertebrates but less efficiently. The insect circulatory system has no veins or arteries. The 'blood' is called haemolymph , and moves around in the space called the haemocoel. The organs sit in the haemocoel and are bathed in the haemolymph. The 'heart' is little more than a single tube which pulses squeezes. Insects start life as an egg.
Usually a female mother insect lays eggs, but a few species have live birth the eggs develop inside the mother. The eggs are small; but they can usually be seen with the naked eye. Although the adults are larger, they do need a magnifying glass or a binocular microscope to see the details. A professional entomologist uses a binocular microscope to identify insects, plus a printed reference work. After the eggs hatch, two kinds of development may occur. Some insects have what is called 'incomplete metamorphosis '.
This means that a small insect, called a nymph comes out of the egg, and the nymph looks almost the same as the adult insect. As the nymph grows, it does not change the way it looks, but only how big it is. It goes through a number of stages, called 'instars'.
Grasshoppers grow in this way. Other insects have complete metamorphosis , which means that the small larva which comes out of the egg looks very different from the adult insect. Insects that have complete metamorphosis usually come out of the egg as a larva , which usually looks like a worm. The larva eats food and gets bigger until it turns into a pupa. Butterfly pupae plural for pupa are often inside cocoons. Inside the cocoon the insect changes the way it looks and often grows wings. When the cocoon opens, the adult insect comes out. Many insects have complete metamorphosis, for example beetles, butterflies and moths, and flies.
The adult stage of development is called the imago.
The oldest known insect fossil is the Devonian Rhyniognatha , from the million year old Rhynie chert. It may have superficially resembled a modern-day silverfish insect. This species already possessed mandibles of a type associated with winged insects, suggesting that wings may already have evolved at this time.
Thus, the first insects probably appeared earlier, in the Silurian period. In , researchers uncovered what they believe is the world's oldest known full-body impression of a primitive flying insect, a million-year-old specimen from the Carboniferous period. The origins of insect flight remain obscure, since the earliest winged insects currently known appear to have been capable fliers. Some extinct insects had an additional pair of winglets attaching to the first segment of the thorax, for a total of three pairs.
It seems the insects were not a particularly successful group of animals before they evolved wings. Upper Carboniferous and Lower Permian insect orders include both living groups and a number of Palaeozoic groups, now extinct. Darpa's call for insect cyborgs piqued the interest of Michel Maharbiz , an electrical engineer at the University of California, Berkeley. He figured that most scientists taking on Darpa's challenge would work with flies or moths, longtime laboratory superstars, but Maharbiz came to believe that beetles were a better bet.
Compared with flies and moths, beetles are sturdy animals, encased in hard shells, and many species are large enough to carry significant cargo. That meant that the first challenge was to unravel the insects' biology.