by Amy Stewart
Males approach with caution, first assessing whether the female has had anything to eat lately. If she looks well fed, the male has some hope of getting through the ordeal alive.
GOLDEN ORB-WEAVER
Nephila plumipes
This Australian spider is remarkably cannibalistic. Roughly 60 percent of sexual encounters end with the female eating the male, and, in fact, the males make up a significant part of the females’ nutritional intake. To make matters worse, the males are often unable to disentangle themselves from their female partners without breaking off part of their own sexual organ and leaving it inside the female.
While this could be seen as a genetic advantage — in the bug world it is not uncommon for males to leave behind a “genital plug” that prevents other males from mating with their chosen partner — this does not appear to be the case with Nephila plumipes. Other males are perfectly capable of mating with a female, simply working around the wreckage of her last encounter.
Researchers have said that because of this injury, “males can expect a limited mating success even if they survive copulation . . . Thus, the costs of post-mating cannibalism for males may be rather small.” In other words, with no prospects of another sexual encounter in their future, they might as well get eaten — at least providing one decent meal for the mother of their children as their final act of parenthood.
CRAB SPIDER
Xysticus cristatus, others
Considering the hazards of lovemaking faced by males in the arachnid and insect worlds, it is no wonder that some species of crab spiders have come up with another plan. Male crab spiders have been observed approaching females cautiously, tapping on them to gauge their readiness for courtship, and then quickly wrapping a few silky threads around the female’s legs to hold her down during mating. This form of bondage is politely referred to as a bridal veil by scientists who have observed the ritual.
PAINFUL
Asian Giant Hornet
VESPA MANDARINIA JAPONICA
In the last few years, during dry summers, public health officials in Tokyo have warned citizens that the world’s largest and most painful hornet may be in their midst. The so-called Asian giant hornet, known locally as yak-killer, delivers a venomous sting that contains high levels of the pain-inducing compounds normally found in bee or wasp stings, along with a deadly neurotoxin called mandaratoxin that can be fatal. The world’s leading expert in the giant hornet, Masato Ono, described the sting as feeling like “a hot nail through my leg.” Worst of all, the sting attracts other hornets to the victim through the pheromones it leaves behind, increasing the likelihood of being stung several times.
SIZE:
50 mm
FAMILY:
Vespidae
HABITAT:
Forests and, increasingly, cities
DISTRIBUTION:
Japan, China, Taiwan, Korea, and other areas throughout Asia
In Japan these hornets are called suzumebachi, which translates to “sparrow wasp.” They are so large, measuring five centimeters from head to tail, that when they fly they actually resemble small birds. During hot summers they can be seen in Japanese cities foraging in garbage cans for bits of discarded fish to carry back to their young. Because they are so willing to venture into urban areas in search of food, about forty people die every year after being stung by the massive hornets.
If such a creature is frightening to humans, imagine what it must look like to a honeybee. Scientists observing wild colonies of the Japanese honeybee, Apis cerana japonica, have long known that the colonies are vulnerable to attacks from the giant hornets. Usually a single hornet shows up first to scout the area. It kills a few bees and brings them back to the hive to feed its young. After more of these trips, the hornet tags the hive by smearing it with pheromones, signaling that it is time for an attack.
A gang of about thirty hornets descend on the hive, and within a few hours these monstrous creatures massacre as many as thirty thousand of the small honeybees, ripping off their heads and tossing their bodies on the ground. Once they’ve killed the bees, the hornets occupy the empty hive for about ten days, robbing it of its honey and stealing the bee larvae to feed their own children.
Recently, Masato Ono and his colleagues at Tamagawa University discovered that the Japanese honeybees had devised an extraordinarily clever way of attacking back. The first time a solitary hornet approaches the hive, worker bees retreat inside, luring the hornet to the entrance. Then an army of over five hundred honeybees surround the hornet, beating their wings furiously and raising the surrounding temperature to 116 degrees — just hot enough to kill the hornet.
This is a dangerous procedure for the honeybees: if the swarm gets just a few degrees hotter, it will kill them as well. In fact, some worker bees do die in the struggle, but the swarm pushes them out of the way and carries on until the hornet is dead. It can take twenty minutes for the honeybees to bake their enemy to death. While it is not unusual for insects to mount a group defense against an enemy, this is the only known case of using body heat alone to defeat an attacker.
The world’s leading expert in the giant hornet described the sting as feeling like “a hot nail through my leg.”
The hornets’ extraordinary strength led Japanese researchers to test an extract of their stomach juices as a performance enhancement for athletes. They discovered that adult hornets, which can fly incredible distances in search of food, are actually unable to eat much solid food themselves because their digestive tracts are so small. However, they do bring dead insects back to their young to eat. After the larvae have finished their meal, the adults tap on their heads, which prompts the larvae to offer up a “kiss” consisting of a few drops of clear liquid. The adults drink this liquid, using it as a source of fuel. The Japanese scientists harvested the clear liquid, one drop at a time, from larvae they found in over eighty hornets’ nests. In the laboratory they demonstrated that both mice and graduate students showed reduced fatigue and an increased ability to turn fat into energy after drinking the juice.
Marathon runner Naoko Takahashi, who won an Olympic gold medal in Sydney in 2000, credited her success to this “hornet juice.” As a natural substance, it didn’t violate the International Olympic Committee rules on performance enhancers. Today an athletic drink called hornet juice is marketed to athletes with the claim that it boosts endurance. However, these drinks don’t contain actual extracts from giant hornet larvae, just a mix of amino acids intended to mimic the powerful juice.
Meet the Relatives Giant Asian hornets are related to other hornets, which are distinguished from wasps by their larger heads and more rounded abdomens. The European hornet, Vespa crabro, delivers a nasty sting when disturbed, but it is no more deadly than the sting of any other hornet.
DEADLY
Assassin Bug
TRIATOMA INFESTANS
In 1835, a young Charles Darwin recorded a strange encounter with a bug in Argentina. He was near the end of his journey on board the HMS Beagle, a British naval ship charged with surveying South America. Darwin had been hired on to fulfill the roles of scholarly companion to the captain and ship’s naturalist. The journey had already been fraught with peril: the captain was unstable and ill-tempered; the locals attacked the crew and robbed them; and most everyone was beset by illness or hunger at some point. Then, on March 25, Darwin himself became dinner for one of the region’s bloodsucking insects. In his diary he wrote, “At night I experienced an attack (for it deserves no less a name) of the Benchuca, a species of Reduvius, the great black bug of the Pampas. It is most disgusting to feel soft wingless insects, about an inch long, crawling over one’s body.”
SIZE:
15–25 mm
FAMILY:
Reduviidae
HABITAT:
Generally found near prey, which could mean homes, barns, nests, caves, or any shelters where birds, rodents, or other animals live
DISTRIBUTION:
North and South Americ
a; some species in India and Southeast Asia
He also recounted an experiment in which several of his shipmates offered themselves up to the bloodthirsty beasts: “When placed on a table, and though surrounded by people, if a finger was presented, the bold insect would immediately protrude its sucker, make a charge, and if allowed, draw blood . . . This one feast, for which the benchuca was indebted to one of the officers, kept it fat during four whole months; but, after the first fortnight, it was quite ready to have another suck.”
What Darwin didn’t know — what no one knew at the time — was that the bite of some assassin bugs can transmit a fatal illness called Chagas disease. These large, oval-shaped insects belong to the family Reduviidae; within that family, there are about 138 species of the bloodsucking Triatoma genus worldwide, half of which are known to transmit the disease. Most are found in North and South America, although there are some species in India and Southeast Asia. They live quite comfortably alongside their hosts, hiding out in burrows and nests and feeding on small rodents or bats. They’re not shy about moving into houses or barns, either. In some parts of Latin America, where palm fronds are used as roofing material, the bugs are inadvertently introduced to local households through eggs attached to the fronds.
Assassin bugs go through five nymph stages on their way to adulthood, drinking up to nine times their weight in blood during a single feeding. An adult female might live six months, and during that time, she’ll lay one hundred to six hundred eggs, the precise number depending on how much blood she consumes.
In most cases, the bite of the assassin bug causes no pain. It may feed for just a few minutes or up to half an hour, its body growing engorged as it drinks. A home with a severe infestation might contain several hundred bugs, and in this case it would not be uncommon for as many as twenty bugs to feed on an individual person, taking one to three milliliters of blood per night. Health care workers visiting the homes of patients recognize the worst infestations of these bugs by the streaks of black-and-white waste products running down the walls.
The assassin bug’s preference for feeding around the mouth of its victim has earned it the nickname “kissing bug”; unfortunately, it can be the kiss of death. In 1908 a Brazilian doctor named Carlos Chagas was studying malaria when he noticed this bloodsucking insect and decided to find out whether it was carrying any disease-causing microbes. What he found was a protozoan parasite called Trypanosoma cruzi that the bug takes in during a meal. The parasite develops and multiplies inside the gut of the bug, and is then excreted in its feces. People get infected by the disease not from the bite itself, but from the feces deposited on the skin of the victim while the bug feeds. Scratching or rubbing the bug bite pushes the waste into the wound, introducing it to the bloodstream. (North American assassin bugs wait to do their business until about a half hour after they have eaten, by which time they have moved away from the victim. This helps explain why the disease is less common in the United States.)
What is most remarkable about Chagas’s discovery is that he found the disease inside the vector insect first, then went on to diagnose humans who were infected with it. Once he did, he realized that he’d stumbled across a fatal disease that seemed to be linked to colonization. As settlers cleared land in the jungle and built mud and palm-thatched huts, the assassin bugs that were already living in the jungle and carrying the disease from one rodent to another found themselves suddenly living among humans — a fantastic source of warm, rich blood. Although the locals had already named the bug — some called it vinchuca, which meant “that which lets itself fall” from the roof, and some called it chirimacha, which meant “that which fears the cold” — the disease caused by the bug was just starting to become widespread around the time Chagas discovered it.
The assassin bug’s preference for feeding around the mouth of its victim has earned it the nickname “kissing bug”; unfortunately, it can be the kiss of death.
People who are bitten around the eyes develop a terrible swelling. Bites elsewhere on the body result in small sores that give way to fever and swollen lymph nodes. The disease can kill in its early stages, but most people go on to experience a symptomless phase, followed by extensive damage to the heart, intestines, and other major organs, which may ultimately be fatal. About three hundred thousand people in the United States live with Chagas disease, and eight to eleven million people throughout Latin America suffer from it. Although early treatment can kill the parasites, there is no treatment for the later stages.
Some historians speculate that Charles Darwin himself was infected with Chagas disease and ultimately died from it. This would explain some of the strange and complicated health problems that plagued him throughout his life. However, the fact that he seems to have suffered from some of the same symptoms before he encountered the assassin bug in Argentina argues against that theory. Requests to exhume his remains from Westminster Abbey and test them for Chagas disease have been denied, leaving the exact cause of his health problems a mystery.
Meet the Relatives Wheel bugs, which prey upon caterpillars and other garden pests, are a type of assassin bug. Other relatives include the so-called thread-legged bugs, a group of long, skinny insects whose victims include spiders and other bugs.
DANGEROUS
BUGS OF WAR
Fifty years ago, in response to the launch of the Soviet satellite Sputnik, the U.S. Department of Defense formed a forward-thinking research office called DARPA, the Defense Advanced Research Projects Agency. Since then, DARPA researchers have developed stealth aircraft, new submarine technology, and an early version of the Internet, among other things. And now they’ve turned their attention to cyborg insects.
The Hybrid Insect Micro-Electro-Mechanical System (HI-MEMS) seeks to implant computer chips inside caterpillars before they undergo metamorphosis into moths or butterflies. Scientists hope to use that circuitry to remotely control the flight path of insects so that they can someday be used to fly into enemy locations and transmit intelligence without ever being detected.
While the HI-MEMS program sounds too strange and futuristic to be true, it is simply the latest in a long history of deploying insects in war. Entomologist Jeffrey Lockwood studies the use of bugs in warfare; his research reveals that even beloved insects like honeybees have been used with malicious intent.
BEES AND WASPS
Bees and wasps have been used as weapons for thousands of years. Hurling a beehive or wasp nest at an enemy is an effective way to create havoc and send even the fiercest warriors running. Mayans had been using them since 2600 BC; their legends describe the use of human dummies with a gourd filled with stinging insects for a head. Early Greek writings on warfare described the practice of building tunnels under enemy walls and releasing bees and wasps into the tunnels. The use of catapults to hurl hives over enemy walls dates back at least to Roman times and continued through the Middle Ages.
But bees weren’t used only during ancient times. As recently as World War I, Tanzanians hid beehives in the undergrowth and rigged their lids with trip wires so that invading British troops would encounter them in their efforts to seize control of the area from the Germans.
One of the most intriguing uses of bees in warfare was recorded by a contemporary of Socrates named Xenophon. He described the use of poisoned hives in Greek warfare around 402 BC: “All the soldiers ate of the combs, lost their senses, vomited, and were affected with purging, and none of them were able to stand upright; such as had eaten a little were like men greatly intoxicated, and such as had eaten much were like mad-men, and some like persons at the point of death.” The soldiers had, apparently, been given beehives filled with the honey of bees that had feasted on rhododendron and azalea, plants that produce neurotoxins so potent that they remain active in the honey. Those who eat the honey succumb to honey intoxication, also called grayanotoxin poisoning.
ASSASSIN BUGS
These bloodsucking creatures that transmit Chagas disease have been used as instrum
ents of torture in so-called bug pits. The most well-known example comes from 1838, when a British diplomat named Charles Stoddart arrived in the city of Bukhara in Uzbekistan to try to win over the local emir and enlist his support in halting the expansion of the Russian empire. Instead of making friends, he was branded an enemy and thrown into the bug pit, a hole beneath the zindan, a traditional Central Asian prison. There he suffered the attacks of assassin bugs, which were kept alive in between prisoners with gifts of fresh meat. A stone chute delivered manure from the stables above, which further attracted bugs and generally made the pit a place of misery.
A fellow British officer, Arthur Conolly, tried to rescue Stoddart after a couple of years, but he, too, was thrown into the pit. The men were literally eaten alive; accounts of the few times they were seen aboveground describe them as covered in sores and lice. The insects did not kill them, however: to accomplish that, they were beheaded in a public ceremony in 1842.
SCORPIONS
Even when they don’t sting, scorpions look terrifying. Pliny the Elder wrote in about 77 AD that the scorpion was “a dangerous scourge, and has venom like that of the serpent; with the exception that its effects are far more painful, as the person who is stung will linger for three days before death ensues.” He added that the sting of a scorpion was “invariably fatal to virgins, and nearly always so to matrons.”
In the ancient city of Hatra, not far from Kirkuk and Mosul in Iraq, scorpions were deployed by local leaders in about 198 AD. They were defending their walled city against an attack by Roman troops led by Septimius Severus. When the troops arrived, the leaders had filled clay pots with scorpions — probably collected from the surrounding desert — and readied these venomous bombs to hurl at their attackers. Herodian of Antioch, a Roman historian writing at the time, described the scene this way: “Making clay pots, they filled them with winged insects, little poisonous flying creatures. When these were hurled down on the besiegers, the insects fell into the Romans’ eyes and on all the unprotected parts of their bodies; digging in before they were noticed, they bit and stung the soldiers.” Although scorpions don’t fly, historians believe that the bombs contained scorpions along with an assortment of stinging insects, perhaps also including bees and wasps.