KINDS OF INSECTS: MANTIDS, CICADAS AND ONES THAT KILL HUMANS

WORLD’S LONGEST AND LARGEST INSECTS

large stick insect

Among the longest, largest and fearsome-looking insects are 30-centimeter-long walking sticks, and predatory water bugs with front legs that have evolved into long, wicked, sickle-like pincers used for snaring prey. The largest of these water bugs are as big as a man’s hand and capable, according to some, of putting a hole in it.

Raphael G. Satter of AP wrote: Nearly the length of a human arm, a recently identified stick bug from the island of Borneo is the world's longest insect, British scientists. The specimen was found by a local villager and handed to Malaysian amateur naturalist Datuk Chan Chew Lun in 1989, according to Philip Bragg, who formally identified the insect in this month's issue of peer-reviewed journal Zootaxa. The insect was named Phobaeticus chani, or "Chan's megastick," in Chan's honor. [Source: Raphael G. Satter, Ap, October 16, 2008]

Paul Brock, a scientific associate of the Natural History Museum in London unconnected to the animal's discovery said there was no doubt it was the longest extant insect ever found. Looking more like a solid shoot of bamboo than its smaller, frailer cousins, the dull-green insect measures about 22 inches (56.7 centimeters), if its delicate, twig-like legs are counted. There are 14 inches (35.7 centimeters) from the tip of its head to the bottom of its abdomen, beating the previous record body length, held by Phobaeticus kirbyi, also from Borneo, by about an inch (2.9 centimeters).

Wetas are the world's largest insects. Found only in New Zealand, they are basically crickets without wings that have changed little in the last 200 million years. There are ten different species of weta. The largest species lives on Barrier Island off the coast of the North Island. It weighs about 2.5 ounces and is about the size of a mouse. Different species of weta inhabit different regions of the country. The most common species, the tree weta, is found mostly in lowland forests. It is large enough to fill a man's hand and when it is alarmed it kicks with its back legs. [Source: Mark Moffet, National Geographic, November 1991]

Water Insects

Water striders have three pairs of legs like all insects. The long middle and rear legs are used to scull the insect over the water surface with surprising busts of speed. The front legs are shorter and used for holding prey. All water striders legs’s are covered with millions of tiny hairs that trap air bubbles and keep the insect on the surface of the water. In addition, water repelling oils are secreted from glands at the tip of the legs and the insects light weight (it weigh less than 1.10th of a gram) also help to keep them aloft.

When an insects falls into the water and starts struggling to get out it sets off a series of ripples that spread across the water and the sensitive antennae of water striders can pick up. When the water strider reaches its prey it forces its sucking mouthpart through a joint or kink in the prey’s exoskeleton and uses it saliva tube to inject various chemicals into the prey that paralyzes its nervous system and liquefies its flesh, making it easier to sucks. A large insect will attract a bunch of water striders, pushing and jostling like lions or hyenas feeding on a fallen wildebeest.

Some predatory water bugs such as water scorpions have a long attachment running to their abdomen, which functions like a snorkel and allows them to remain submerged while they lay in wait for prey.

According to IUCN data, 16 percent of assessed dragonfly and damselfly species are threatened, and around 10 percent are in decline. While the April 2020 Science study noted a decline in insects on land, it found that freshwater insects are recovering at a rate of 11 percent per decade overall thanks partly to clean water legislation passed in Europe and the United States. But the situation is worsening in South Asia and Southeast Asia, where many wetland breeding grounds have been cleared for crops. Today, more than a quarter of the region’s dragonflies and damselflies are threatened. [Source Julia Janicki, Gloria Dickie, Simon Scarr and Jitesh Chowdhury, Reuters. December 6, 2022]

Mantids

orchid mantis (Hymenopus coronatus)

Mantids are long predatory insects that include praying mantises. In temperate climates mantids hatch in the spring and grow and molt during the summer months. By autumn they have reached adulthood and are ready to begin mating. Mantids lay their eggs inside protective sacs called ootheca, The sac is made of foam secreted by the females along with her eggs. At first the foam is soft, but when it come in contact with air it hardens into a tough, fiber-like material that protects the eggs throughout the long winter months. The adults all die off with the onset of cold weather.

Mantids are first rate hunters. Rather than stalk prey they wait patiently, well camouflaged against their backgrounds, grabbing unsuspecting prey as they pass by with a quick lung. Sharp jaws are used to cut the prey into bit-size pieces. One of their favorite places to catch prey is just below blooming flowers where they wait to pounce on insects coming to the flower to sip nectar or collect pollen.

A mantid’s front pair of legs are lined with barbs that are designed to seize and hold prey. At the tips of each of these legs is a large, curved spike, which is often used to like a grappling hook to make the initial grab. Once the prey is secured in between the legs the mantis methodically tears the prey to pieces and eats it.

Taryn L. Salinas wrote in National Geographic: As early as the ancient Greeks, people have credited mantids with supernatural powers. In parts of southern Europe, the belief was that a praying mantis would point a lost child home. In the Muslim world, it was thought that a praying mantis always prayed facing Mecca. The Kalahari Bushmen sometimes envision their creator deity, Kaang, as a mantid. In that incarnation, he is known as the "great magician." Although in many parts of Asia mantids are often considered pets and are frequently handled lovingly, they have also been used as fighting animals, battling to the death in bamboo cages. In fact, several styles of kung fu, known as Tang Lang in Chinese, were inspired by the insect's merciless and predatory maneuvers. Practitioners of the praying mantis style imitate the tactics that the creature uses to trap and maim its prey.

Why Female Mantids Eat Their Mates During Sex

According to Smithsonian.org “For the male praying mantis, mating can be deadly. That’s because the female of the species is, quite literally, a maneater. Male mantises frantically pursue a mate just before winter sets in, when they are facing an imminent, slow death. Perhaps that’s why they don’t seem to mind the second option: Being decapitated and eaten alive mid-fornication.

“Why do the female bugs turn cannibalistic mid-shag? Sex takes a lot of energy, and devouring their partner is a great source of nutrition that boosts her ability to produce fertilized eggs. She’ll start with the head, because male mantises can actually keep at it for a while without it. (In one documented case, a female ate her mate’s head before they got busy and he still did the deed.)

“As a male perishes, his abdomen spasms, pumping sperm into the partner and thus increasing the likelihood of mating success. When it’s all said and done, the female gobbles up her mate’s carcass, his lifeless body. A gruesome way to go, but at least he didn’t die cold and alone? [Source: Katherine J. Wu , Rachael Lallensack, Smithsonianmag.com, February 14, 2020]

Katydids, Crickets and Grasshoppers

Crickets, grasshoppers cicadas and katydids make sounds. Since most insects are deaf this means they have to have ears to hear their sounds. Crickets and katydids make their sound by rubbing their wings together. Grasshoppers make their sound by sawing a strengthened vein on their wings against notched edges on their hind legs.

Crickets chirp at rates of 4 or 5 times a second to more than 200 times a second. Crickets chirp faster when the weather is hot, with the rate varying from species to species. One species, the snowy tree cricket chirps so reliably a formula called Dolbear’s Law (named after A.E. Dolbear, who reported the finding in 1897) produces a temperature gauge. Count the number of chirps in 15 second and add 40 and you get the temperature in Fahrenheit.

Katydids flourish in humid, tropical regions around the world and are particularly numerous in rain forests. Some are brightly colored to warn predators than an unappealing meals awaits them if they take a bite. Other avoid trouble by disguising themselves as leaves or lichens.

Grasshoppers have wings but don’t fly very well. The first segment, or femur, of the hind leg is long and wide, containing powerful muscles that can launch the insect to their spectacular jumps, with their wings used to extend their flights. On the second segment, or tibia, of the hind leg are a line of nasty barb that help defends the insects from attack from behind. Birds such as crows that regularly feed on grasshoppers have dense tufts of hair that thick out from the bases of their beaks that help protect their eyes.

Cockroaches are among the oldest creatures still on the earth. They first appeared about 300 million years ago.

Cicadas

Cicadas are the noisiest of all insects, They make their sound by vibrating tiny membranes called tymbals that are snapped in and out by powerful muscles that can move back and forth 600 times a second. The sound is amplified in a large empty resonating chamber then forced through flaps. Males sing to define their territory to potential male rivals and to attract females.

Cicadas hear with circular eardrums on either side of their thorax. Many cicadas are large and fearsome looking by the they don’t bite or sting. They generally live a relatively short life in their adult form. The spend most of the life underground sucking on roots.

Cicadas spend nearly their entire lives under ground. They come to the surface for a few frantic weeks of mating before using up their strength and dying, often signaling summer is coming to an end.

In many species of cicada females lay their eggs in slots which they cut into tree twigs. When the eggs hatch they drop down to earth where the larvae quickly burrow into the ground. The larvae feed on tree roots and take a long time to grow. The smaller species are ready to come to the surface in two or three years but the large ones take five to seven or even longer. The 17-year locusts (a kind of cicada) are the most famous of these.

Fleas

The first fleas appeared around 50 million years ago. Today there are about 2,000 different species. The male sex organ of some flea species is a complex device that takes up a third of the male’s body and contains spines, lobes and tickling devise that resembles a feather duster. Inside the females body it must follow a meandering route with many wrong turns to the place where sperm is deposited. Penetration can take up to 10 minutes and copulation can last between three and nine hours.

Flea jumps of 34 inches has been recorded. If a fleas' jumping skill were transferred to a human that human would be able to leap over the Statue of Liberty a 600mph continuously for three days straight. Their incredible strength and jumping ability explains why they were recruited for flea circuses.

To hop, fleas use a devise based in a structure in their flanks that once served as a hinge for their ancestors wings and is made from an elastic substance called resilin. When a flea gets ready to jump the resilin is slowly compressed and then locked into position. When it is released it produces an audible click and straightens the flea’s leg with an incredible amount force.

Tsetse Flies — the World’s Fourth Deadliest Animal

Tsetse flies are regarded as the world’s fourth or fifth deadliest animal, killing about 10,000 people a year, according to CNET and Business Insider. Tsetse flies transmit sleeping sickness, whose symptoms are fever, confusion, lethargy, anemia, uncontrolled sleeping, seizures, delirium and finally coma. There are two strains of the disease that affect humans: a slowing-acting form found in western and central Africa and the more virulent East African form that begins with a headaches and joint pains and may kill within weeks.

Tsetse flies are insects that don't look much different from a housefly but they have a dart-like proboscis capable of penetrating rhino hide and canvas clothing to inflict a painful bite. The disease itself is caused by microscopic parasites called trypanosomas which don't originate in tsetse flies, but are carried from host to host as malaria is.

There are a couple dozen species of tsetse fly but only ones that have picked up the disease from a stricken mammal carry it. The disease is easily cured if detected early; it become dangerous when it passes in to the nervous system where drugs powerful enough to kill the parasites are just as dangerous as the disease itself.

Tsetse flies live about six months. females produce one young at a time and 12 or so in their lifetimes. The tsetse fly larva are born alive and nourished by fluid released from a nipple on the wall of a pouch where the larva lives and breath through special tubes that protrude from near the genital opening.

There are 54 countries in Africa and over 40 of them of have tsetse flies living in at least one part of the country. Tsetse fly species fall into three different groups: the savannah species, the forest species and the riverine species. The flies live pretty anywhere there isn't highlands too cold for them or deserts to dry.

Assassin Bugs — Deadly Tool-Using Insects?

Assassin Bug is the common name used to describe Reduviidae, a large cosmopolitan family of insects in the order Hemiptera (true bugs). They are regarded as the world’s sixth deadliest animal, killing about 10,000 to 12,000 people a year, according to CNET and Business Insider, as a few species from South America transmit Chagas disease. Most are terrestrial ambush predators; some are blood-sucking ectoparasites. Most are recognizable: they have a relatively narrow neck, sturdy build, and formidable curved proboscis (sometimes called a rostrum). It is advised to keep your hands off of large specimens because they sometimes defend themselves with a very painful stab from the proboscis.

There's an assassin bug in Australia that is regarded as a tool-using animal. In a study published in the spring of 2023 in the journal Biology Letters, scientists describe the creative — and deadly — hunting technique type of one type of assassin bug. Maggie Harrison wrote in Futurism: The insect meticulously coats itself in a sticky resin as a means of more effectively catching prey. Per the study, the assassin bug uses a specific resin from a native Australian grass called spinifex grass. "Tool use in animals is a complex and rare phenomenon, particularly in insects," reads the scientists' research. "Tool use in assassin bugs has been suggested as several species apply adhesive plant resins to their body, which has been hypothesized to function in enhancing prey capture." [Source: Maggie Harrison, Futurism, May 7, 2023]

To test the extent of the tiny assassins' tool use, the Australian researchers observed the bugs in the wild as well as in captivity, taking 26 different assassin bugs from the outdoors and placing them in a glass jar with one of two prey: flies or ants. As ScienceDirect notes, flies are particularly difficult to catch. Per the study, the resin-covered assassin bugs had a much easier time catching flies than their glueless counterparts did — of the 26 bugs, those with resin were 26 percent more successful at snagging the pesky winged prey. "Here, we staged predatory interactions of resin-deprived and resin-equipped assassin bugs (Gorareduvius sp.) and discovered that applying resin as a tool conveys a clear predatory advantage to the assassin bugs," reads the study. "Gorareduvius sp. can thus be considered a tool-user, and since this behaviour was present in all individuals, including newly hatched nymphs, tool-use can be considered to be stereotyped."

And apparently, according to the scientists' observations, the use of the spinifex resin isn't a learned behavior, as even newly-hatched nymphs were seen coating themselves in the glue-like substance. "Assassin bugs manipulated an environmental item (the resin), by taking it out of its usual context and applying it onto their bodies," the researchers concluded, "Thus gaining a selective advantage through improved prey capture." Image Sources: Wikimedia Commons

Text Sources: Mostly National Geographic articles. David Attenborough books, Live Science, New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Natural History magazine, Discover magazine, Times of London, The New Yorker, Time, Newsweek, Reuters, AP, AFP, Lonely Planet Guides, Compton’s Encyclopedia and various books and other publications.

Last updated December 2024