by David Braun
Insect brain-drugs for humans are still years away, Lee said, but there’s one hopeful glimmer: When the team added the insect antibiotics to human cells in the lab, there were no toxic effects.
TRUTH:
A COCKROACH CAN LIVE FOR OVER A WEEK WITHOUT A HEAD.
BRAINWASHED BABYSITTERS
Ladybug Incubators
Enslaved by Wasps
Good child care is tough to find, and one kind of parasitic wasp has solved the problem by brainwashing ladybugs into incubating and then protecting its young.
When the parasitic wasp Dinocampus coccinellae is ready to reproduce, it must seek out a nursemaid, a special someone to nurture its young. The bug has come up with a unique recruiting strategy: mind control.
The parasitic wasp prepares to inject a paralyzed spotted ladybug with an egg. (Photo Credit 4.11)
Nurture and Protect
After the wasp finds a spotted ladybug, it paralyzes her with its venom and then injects her with a single egg. In time the egg will hatch into a larva that will develop for a few days and then chew a small hole through the abdomen of the ladybug. The larva will then spin a cocoon between the legs of the ladybug, whose body will rest on top of the cocoon as the larva undergoes metamorphosis.
In a recent study in the journal Biology Letters, scientists note that when the ladybugs survive the larva’s emergence, the D. coccinellae larva then “brainwashes” the bug into defending the vulnerable cocoon from predators, said study co-author Jacques Brodeur, a biologist at the University of Montreal.
“The parasite is taking control of the behavior of its host—that’s why we call it bodyguard manipulation,” said Brodeur, who worked with Ph.D. student Fanny Maure.
With his new research, Brodeur said he has solved a mystery that arose during an outdoor stroll in Canada. “It’s quite common when you are out in the forest to see ladybugs on top of a cocoon—we were wondering why it was like that,” he said.
A wormlike wasp larva emerges from its ladybug host. (Photo Credit 4.12)
Not a Death Sentence
Although most parasites eventually kill their hosts, the wasp-infected ladybugs have a more “atypical fate,” according to the study—some ladybugs survive their “horrible” ordeal. For example, Brodeur’s team observed in field experiments that 30 to 40 percent of the infected ladybugs lived after the young wasp hatched, including some individuals that later laid their own eggs. The host bug can survive because the wasp larva feeds only on tissues that are not crucial for the ladybug’s survival, such as fat, the scientists say.
Once a still living ladybug takes up its post on top of the wasp cocoon, the insect will act aggressively toward intruders by flailing its legs, for example. The scientists suspect the twitching behavior comes from venom left in the ladybug’s body after the larva emerges and builds its cocoon.
Eaten Alive!
The parasitic jewel wasp injects venom directly into a cockroach’s brain to impede its free will. The venom blocks a chemical called octopamine that controls the cockroach’s motivation to walk. The wasp then pulls the “zombie” cockroach into its lair and lays an egg in its abdomen. The larva will eventually hatch and eat the living but immobilized cockroach from the inside out. A mature wasp will emerge from the cockroach after about a month.
Two ladybugs take up their post on top of the wasp cocoon. (Photo Credit 4.13)
The length of time that a wasp larva manipulated a ladybug into protecting its cocoon also varied from insect to insect. In some cases the ladybug stayed vigilant until the larva emerged from its cocoon about 20 days later as a young wasp. In other cases the ladybug was under the wasp’s sway for just a few days, Brodeur noted.
In the lab, Brodeur and his team placed predatory lacewings into petri dishes that contained either cocoons covered by live ladybugs, other cocoons covered by dead ladybugs, or cocoons that lacked ladybug bodyguards. The results showed that the lacewings were less successful in attacking cocoons being protected by the “brainwashed” ladybugs.
The team found that wasp larvae that invested more time and energy into controlling their ladybug bodyguards laid fewer of their own eggs as adults than the larvae that did not. It’s the first time that scientists have shown a trade-off between host manipulation and fertility, he said. But the parasites are very haughty when choosing their bodyguards: They’ll infect only ladybugs.
A newborn wasp after emerging from the cocoon. (Photo Credit 4.14)
THEY’VE GOT THE TOUCH
Male Spiders
Massage Their Mates
When a male golden orb-weaver spider wants to get busy and live to tell the tale, he pulls out a special trick: He gives his mate a “back rub,” new research shows.
For many spiders, mating is a risky, sometimes deadly, proposition—females of the species are much bigger than the males. The female golden orb-weaver spiders (Nephila pilipes) are up to ten times larger than the males. An unlucky suitor might get interrupted in his carnal embrace when a female kicks him off and eats him.
TRUTH:
THE LARGEST SPIDER IN THE WORLD IS WIDER THAN A BASKETBALL.
Staying Alive
Male spiders have evolved multiple techniques to avoid this fate, at least before finishing the deed. Male black widows, for instance, pick up scents from females that help the males determine how hungry their love interests are before attempting to mate. Redback spiders in Australia, meanwhile, actually allow themselves to be snacked on to prolong their time with a female.
N. pilipes’s strategy involves another trait common among spiders: pedipalps, a pair of appendages that includes male genitals, said study co-author Matjaz Kuntner of the Smithsonian’s National Museum of Natural History and the Slovenian Academy of Sciences and Arts.
The male’s pedipalps fit perfectly into the female’s two genital openings, and he can leave them behind to “plug” the openings. But a male needs to mate several times in succession to plug both openings and guarantee the female—which can have multiple partners—will have his babies.
While a female golden orb-weaver in the genus Nephila has a snack, a smaller male touches her body. (Photo Credit 4.15)
To make his mate more receptive between bouts, a male N. pilipes will spread silk over her dorsum, or back, in massagelike motions known as mate binding. N. pilipes is the only orb-weaving spider known to perform mate binding, Kuntner said, although some spiders from other genera have been known to use the same tactic.
Touch-a, Touch-a, Touch Me?
Researchers had previously theorized that mate binding works because pheromones in the male’s silk served to stimulate a female or simply to relax her. But Kuntner’s team wasn’t so sure.
So Kuntner and colleagues Daiqin Li and Shichang Zhang, from the National University of Singapore, blocked female N. pilipes’s sense of touch by covering the spiders’ backs with thin layers of superglue. With a second group of spiders, the researchers removed the females’ sense of “smell,” to test whether they were picking up on chemical cues in the silk.
The team then let the males go at it.
All 17 females that couldn’t “smell” calmed down after getting a massage. Females that couldn’t “feel” were less likely to let their mates get it on more than once—about 40 percent weren’t calmed, and many ate their mates.
Even males that had their spinnerets blocked could avoid being eaten with a well-timed but silkless back rub, the study team observed. The findings show that the silk itself is incidental—the female spiders are probably responding to simply being touched by their suitors. Thus, the paper’s authors say, “mate binding … could also be more descriptively termed mate massaging.’ ”
A Web of Gifts … and Lies?
When male nursery web spiders look for love they present females with a “nuptial gift” of freshly caught prey wrapped in silk. But research has found that only 62 percent of gifts from male nursery web spiders actually contained fresh prey, while the rest contained i
nedible substitutes. Males without gifts are usually rejected, which may explain why some males who become desperate present a worthless gift such as bits of flower, cotton, or ant husks. However, the females aren’t played that easily—a study showed that they disengaged from mating more quickly with the males that gave worthless gifts and moved on.
KIDNAPPED!
Alien Wasps Abduct Ants
Drop Them to Get Food
Looking for a way to banish ants from your picnic? According to a new study, wasps have developed a unique method.
In an experiment done with wild insects, scientists in New Zealand recently witnessed the common wasp, an alien invader to the island country, competing for food with the native ant species Prolasius advenus. When a wasp approached a mound of food swarming with ants, the wasp would pluck an ant from the pile, fly a ways off, and drop the still-living insect from its jaws.
“To the best of our knowledge, this behavior has never been described before,” said study co-author Julien Grangier, a biologist at Victoria University of Wellington.
TRUTH:
MOST WASPS ARE ACTUALLY SOLITARY, NONSTINGING VARIETIES.
Wasps Bigger, but Not Badder
Common wasps (Vespula vulgaris) are native to North America but were accidentally introduced to New Zealand in the 1970s. The wasps eat other insects and nectar, capturing live prey or scavenging. Grangier and colleague Philip Lester had suspected that the alien wasps were competing with native ants for scarce protein sources in New Zealand beech forests.
This suspicion led the pair to establish an experiment in which ants and wasps were presented with samples of high-protein food: little chunks of tuna fish. The samples were placed at 48 stations in a natural beech tree forest, with cameras set up near each one. Both wasps and ants visited 45 of the 48 stations, and the cameras recorded 1,295 interactions between the insects.
In the vast majority of instances, the wasps and ants avoided or ignored each other. However, the researchers documented 341 cases when the ants were aggressive toward the wasps, charging at the larger bugs, biting them, or spraying them with formic acid, a natural defense mechanism.
In just 90 encounters the wasps were the aggressors, including 62 cases of ant dropping. The researchers suspect the other 28 times were ant-dropping attempts that the wasps fumbled. “It was a surprise to see that ants, being 200 times smaller than wasps, can be serious competitors with them,” Grangier said.
Picnic Pests
Western yellowjacket wasps, which were accidentally introduced to Hawaii during the 1900s from the U.S. Pacific Northwest, have an astonishingly diverse diet. Adult yellowjackets consume only nectar, but they kill or scavenge prey to provide necessary protein to their growing offspring. “They basically just carry it in their mandibles—you see them flying with their balls of meat,” said lead study author Erin Wilson. Wilson and her team found that their prey spans 14 taxonomic groups of animals, including tree lice, spiders, rats, and geckos.
Ant Acid Behind Wasp Behavior?
Most of the time, the wasps’ ant-dropping behavior was unprovoked, with ants being simply grabbed and flown away. In a few instances the ants were unruly before they were grappled and carried off.
The team argues that the acid defense may be why the wasps “ant drop” rather than just killing the smaller insects outright. “By not crushing ants and dropping them away as fast as possible, wasps just protect themselves, avoiding further contact with this harmful substance,” Grangier said.
CHAPTER 5
Explaining the Unexplained
(Photo Credit 5.1)
You are about to enter a chapter filled with legendary monsters, mysterious disappearances, and conspiracy theories. These unexplained mysteries have become obsessions, possessing the minds of those who cannot abandon their quest for the answers. What happened to Amelia Earhart over the Pacific? Are there secrets hidden at Area 51? Does Bigfoot roam the forests of North America? Is the truth really tout there? Come with us and find out.
TITANIC’S TRUE STORY
Titanic Discovered
During Secret Cold War Navy Mission
A “Top Secret” hunt for two sunken submarines gave this explorer the chance of a lifetime: to find the final resting place of the Titanic.
The 1985 discovery of the Titanic stemmed from a secret United States Navy investigation of two wrecked nuclear submarines, according to the oceanographer who found the infamous ocean liner. Pieces of this Cold War tale have been known since the mid-1990s, but more complete details are now coming to light, said Titanic’s discoverer and National Geographic explorer-in-residence, Robert Ballard.
“The Navy is finally discussing it,” said Ballard, an oceanographer at the University of Rhode Island in Narragansett and the Mystic Aquarium and Institute for Exploration in Connecticut. Ballard met with the Navy in 1982 to request funding to develop the robotic submersible technology he needed to find the Titanic.
The bow railing of the submerged Titanic (Photo Credit 5.2)
Secret Mission
Ronald Thunman, then the deputy chief of naval operations for submarine warfare, told Ballard the military was interested in the technology—but for the purpose of investigating the wreckage of the U.S.S. Thresher and U.S.S. Scorpion.
Since Ballard’s technology would be able to reach the sunken subs and take pictures, the oceanographer agreed to help out.
He then asked the Navy if he could search for the Titanic, which was located between the two wrecks. “I was a little short with him,” said Thunman, who retired as a vice admiral and now lives in Springfield, Illinois. He emphasized that the mission was to study the sunken warships.
Once Ballard had completed his mission—if time was left—Thunman said, Ballard could do what he wanted, but never gave him explicit permission to search for the Titanic.
Ballard said Navy Secretary John Lehman knew of the plan. “But the Navy never expected me to find the Titanic, and so when that happened, they got really nervous because of the publicity,” Ballard said.
Titanic Debris
The wreck of the Titanic lies in two sections, about 2,000 feet (609 meters) away from each other. In between them is a huge debris field, strewn with pots, pans, plates, and bottles of champagne, as well as personal items: hairbrushes, hand mirrors, a ceramic doll’s head, and a pair of boots.
Sunken Subs
The Thresher and Scorpion had sunk in the North Atlantic Ocean at depths of between 10,000 and 15,000 feet (3,000 and 4,600 meters). The military wanted to know the fate of the nuclear reactors that powered the ships, Ballard said.
This knowledge was to help determine the environmental safety of disposing of additional nuclear materials in the oceans. The Navy also wanted to find out if there was any evidence to support the theory that the Scorpion had been shot down by the Soviets.
Ballard’s data showed that the nuclear reactors were safe on the ocean bottom and were having no impact on the environment, according to Thunman. The data also confirmed that Thresher likely had sunk after a piping failure led to a nuclear power collapse, he added. Details surrounding the Scorpion are less certain.
A catastrophic mishap of some sort led to a flooding of the forward end of the submarine, Thunman said. The rear end remained sealed and imploded once the sub sank beneath a certain depth. “We saw no indication of some sort of external weapon that caused the ship to go down,” Thunman said—dismissing the theory that the Russians torpedoed the submarine in retaliation for spying.
Titanic Facts:
1. Titanic was massive-883 feet long, 92 feet wide, and 175 feet tall.
2. Touted as “unsinkable,” the ship first set sail on April 10, 1912, with 2,223 people on board.
3. The Titanic carried lifeboats for only 1,178 people.
4. At 11:40 p.m. on April 14, the first mate spotted a dangerous iceberg. The ship’s crew attempted to avoid it, but the Titanic was moving too fast and struck the iceberg.
5. The shi
p sank at 2:20 a.m. on April 15, 1912.
6. The wreck of Titanic was found some 13 miles east of its last reported position.
Trail to Titanic
While searching for the sunken submarines, Ballard learned an invaluable lesson on the effects of ocean currents on sinking debris: The heaviest stuff sinks quickly. The result is a debris trail laid out according to the physics of the currents.
With just 12 days left over in his mission, Ballard began searching for the Titanic, using this information to track down the ocean liner. He speculated that the ship had broken in half and left a debris trail as it sank. “That’s what saved our butts,” Ballard said. “It turned out to be true.” The explorer has since used a similar technique to find other sunken ships and treasures, including during his expeditions to the Black Sea. Were these expeditions also part of top-secret missions? After all, the Black Sea is in the volatile Middle East.
“The Cold War is over,” Ballard said. “I’m no longer in the Navy.”
BUSTING THE BIGFOOT BROUHAHA
Bigfoot Discovery
Declared a Hoax
Two men claimed that they had a Bigfoot encounter in the woods of Northern Georgia, but was the whole thing an elaborate hoax?
Alas, the search for Bigfoot continues. No evidence has emerged to support claims made by two men who said they found the corpse of a seven-foot-tall (two-meter-tall) Bigfoot—an apelike creature of North American legend—in the woods of northern Georgia.