- "They were doing research on some parasitic insect...like a wasp. A wasp that turns living things into zombies."
- —Isabela Keyes discussing the Ampulex Compressa Giganteus.
Ampulex Compressa Giganteus are the biologically and genetically modified wasps responsible for the zombie outbreak. Carlito unleashes these wasps on Willamette, zombifying almost the entire population. Dr. Russell Barnaby is one of the scientists who helped to create them, originally intended to curb a meat shortage. Queens are the adult version seen in-game.
Origins and Significance
The Ampulex Compressa Giganteus originated from the region bordering the Pachacamac River near the Central American town of Santa Cabeza. A U.S. government-funded research facility was established in the town, whose scientific personnel, lead by Dr. Russell Barnaby, aimed to find a way to mass-produce the cattle population and reduce the cost of their breeding for the rapidly-increasing American consumer demand. During their research, they discovered the species' presence. It was a previously unidentified and undiscovered species of insect. Though the species was much larger and more aggressive than its similarly-resembled wasp and bee counterparts, the laboratory staff referred to them as such when speaking casually. The team also witnessed firsthand the insect's birth process and its dependency upon host species to live. The wasps also possessed their own version of queens, mature insect matriarchs who conduct the hosting process.
Dr. Barnaby and his research team were going to harness the species and use its abnormal but useful properties to accelerate the production of meat, by using the parahormone to stimulate cattle's appetites and to lead to fatter cows. They experimented on rats and cattle to see what the new species would do to its host and witnessed it zombifying the rats and cattle. Unfortunately, a queen escaped the facility; instead, they witnessed the horrifying effect the species had on humans.
The fully grown ACG specimens appear to have an adverse effect on human hosts, or "zombies", as they can make their heads explode if crushed. This could have something to do with pheromones.
Life Cycle: The Parasitic Process
- A fertilized female incubates its eggs within the womb.
- When the parasite discovers a potential host (generally the South American butterfly known as Thysania Agrippina), it injects an egg into the host's body.
- The virus injected along with the egg effectively prevents the host's immune system from recognizing the contamination, facilitating the larva's growth while keeping the host's physiology blissfully unaware of the danger lurking within.
- The larva excretes a parahormone that stimulates the host's appetite, then absorbs the resultant nutrients to fuel its own growth cycle.
- Once the parasite has grown to the appropriate stage, it devours the host from within, emerging from its cocoon as a full-fledged adult.
Notes: Stage five is observed during Dr. Barnaby's death scene. The wasp induced "crazed" convulsions and seemed to cause a lot of havoc in its victim.
Queens are first encountered by Frank inside the warehouse around 6 pm. Before it can sting Frank, he swats it out of the air and stomps on it, causing all the surrounding zombies to immediately die. After this, queens can be found anywhere on certain zombies and can be used to kill large groups of zombies. These zombies stand in the same spot and move their arms in the air, almost like they are yawning, and will sometimes throw up blood (stunning Frank if he comes in contact with it), then will fall to the ground and their heads will literally explode. Zombies that have a queen attached to them are immune to its effects. When Frank drinks a nectar juice, a queen will automatically be attracted, and queen zombies become more common. The queen can be picked as if an ordinary weapon and will be stored in a jar which can then be thrown at the ground near Frank or in the distance.
The queens will not harm Frank. However at night, the Queen larvae, which are glowing green, that come out of the zombies killed using the Queen will jump at Frank, but barely causing any damage. This new aggression and activity is likely connected to why Zombies are stronger and more aggressive at night.
At one point, Kent Swanson tries to use a Queen larvae on a captured survivor so that he can photograph the exact moment a human becomes a zombie, but is stopped by Frank West. It is shown that the larva is rather large, easily filling a person's hand, with a white body, segmented back, and a black, featureless head embedded in a ring of white flesh. It has no legs, no mouth, green blood, and glows bright bioluminescent green at night, as well as being much more aggressive than they are normally.
A large dose of hormone harvested from corpus allatum of several adult Queens, specifically ten, are used by Isabela to temporarily supresses the growth of the parasite larvae in a infected person's blood and stall the zombification process, based on an earlier version of the drug that was created when Carlito tasked her to research a method to supress the parasite. She explains that when the drug was first made, she can and Carlito did not extract the hormone directly but instead synthesized it in a lab. She used this drug on Frank using some improvised equipment after the Special Forces invade and the survivors escape the mall. This would lead to the creation of what would soon become Zombrex. Isabela also uses the remains of the captured Queens to isolate a pheromone that suppressing the attack instinct in adult parasites, repelling zombies as they "don't like the smell". When inside the Clocktower Tunnels, Frank must hold hands with Isabela so that the repellent affects both of them, as she only has enough for one that she holds to protect herself.
Carlito ordered Isabela to make this suppressant drug as part of his contingency revenge plan with his Infected Orphans: fifty orphans from Santa Cabeza, products of the U.S. raping local women before the zombie outbreak. Carlito infected them with the parasite but also gave them the zombie-suppression drug Isabela created, before using a Non-Profit Organisation he had started, that was dedicated to helping war orphans, to find new homes for them across the United States. These children were zombie "time-bombs" that, depending on their individual physiologies, would transform at random into zombies once the suppressant wore off, starting outbreaks all over the country. However, not wanting to make something completely unstoppable, he made one orphan immune to the parasite so a proper vaccine was possible.
Dead Rising 2: Case Zero
Queens are first encountered by Chuck as he exits the scrapyard for the second time, after he returns the bike chassis. Before it can sting Chuck, he swats it out of the air and steps on it, which was followed immediately by the zombies surrounding him dying. After this, queens can be found anywhere on certain zombies. The Queen is exactly the same as the first game, but is slightly larger, and has a blur to it when it moves.
Dead Rising 2
Chuck first encounters a Queen after the second dose of Zombrex on Katey. He immediately swats it and the Queen falls half dead to the ground. He then steps on it and the heads of the zombies explode. In Dead Rising 2, the queens are the reason for the Fortune City outbreak, since it was caused to extract them from the zombies in order to raise the prices and production of Zombrex. Furthermore, a gas that lead to the creation of the mutated Gas Zombies was developed by Phenotrans in order to speed up the maturity of Queens for faster harvesting in order to make Zombrex quicker to keep up with the country's supply-and-demand.
Dead Rising 3
Another part of the parasite's life cycle is shown in the form of large, segmented white-with-black-ringed worm creatures with lamprey mouths that squirm under the bodies of infected people that have yet to turn into Zombies, causing skin bulges and itching. These worm creatures are not elaborated on, but are lightly implied to be the post-larva stage/mutated larva of the Queens, as they are more aggressive and look different to the larva shown in the original Dead Rising. They are shown able to be harvested and used by John Hemlock and Marian Mallon, and can be used to turn people into Zombies instantly by force-feeding them, which is what they do with President Sonya Paddock so they can film her and allow Hemlock to take emergency control of the government.
Diego Martinez is at one point kidnapped and experimented on by Marian and Hemlock's forces with a laser that will fully grow the parasite within his body, in order to test to see if he is was the member of Carlito's Infected Orphans that contains the vaccine to the zombie virus within him. However, as he didn't, it caused his body to burst open from all the swarm Queens and worms escaping his body and infecting the nearby soldiers, killing Diego in the process.
King Zombies are mutated variants of the Zombies due to the unique radiation used to turn off people's Zombrex microchip. Becoming living, walking hives for dozens and hundreds of Queens which they can control, Hemlock planned to use these King Zombies to create a new zombie biological weapon to spread across the United States.
Dead Rising 4
During the events of Dead Rising 4, a vaccine has been created to make humans immune to the parasite and the virus. However, an old strain of the virus from Santa Cabeza, immune to the vaccine and to Zombrex, resurfaces to allow the parasite to make zombies and terrorize the population once again. Furthermore, Obscuris has secretly been running zombie experiments by making clones and infecting them to study the infection and modifying zombies; making them stronger, faster, smarter, and speeding up the rate of zombification from days to seconds, in hope of creating mass-produced, cheap, immortal labour.
In addition, Barnaby's old machinery in Willamette lead to both the Second Outbreak, and the creation of mutated Queens responsible for Calder and a new Evolved Zombies variant that were the result of Barnaby's failed attempts at immortality; maintaining the tireless, ageless, illness-proof body of a zombie but without the decay, bestial hunger, and lack of intelligence.
- In real life, Ampulex Compressa is the taxonomic name of the Emerald Cockroach Wasp. They are native to South Asia and the Pacific Islands but were accidentally introduced to South America, becoming an invasive species.