Make Room! Make Room!

"Make Room! Make Room!" in the time of Covid. Can an aphid sneeze?

It was easy to connect Harry Harrison's science fiction story "Make Room! Make Room!" to the image of the aphids under my microscope, crowded together on a tomato stem, literally crawling over each other for food. In Harrison's story, later made into the movie "Soylent Green," the masses struggle for food, while an elite few live comfortably. A theme that resonants to current times. But after a year of Covid isolation, this crowd of insects had me thinking about diseases of insects, the bugs of bugs. If we had to stay six feet apart to prevent the spread of Covid, does the crowding of insects ever become a "super spreader" event?

First there has to be a bug pandemic. Insects suffer from the same types of pathogens as humans: viruses, bacteria, and fungi. Like their larger counter parts, these diseases are usually very specific to a species or genus. For example, viruses that effect caterpillars should not effect aphids.

For a reminder of the organization of living things, from biggest group to smallest according to Linnaeus: Kingdom > Phylum > Class > Order > Family > Genus > Species. So for humans it is Animalia (kingdom) > Chordata (phylum) > Mammalia (class) > Primates (order) > Hominidae (family) > Homo (genus) > sapiens (species). So a genus is a group of closely related species.

Back in my bug days, one of the divisions within the Entomology Department was insect pathology. If you could find ways that insect pests naturally die, then replicate the pathogen on a large scale, you could declare biowarfare on the pest. The idea was to find the natural pathogen of a pest, formulate a method to apply it to a crop that was infested with the pest, and cause mass sickness (to the pest) followed by death. Since the pathogens were species or at least genus specific (you hoped!), the outbreak would only effect the target pest and not beneficial insects, wildlife or humans.

Most of the vegetable plants in your garden are not native to your location and neither are the pests. The pathogens of your pest are not just sitting around waiting for a host. Unless the pest showed up in your yard with a deadly insect microorganism, it is very unlikely there will be an insect pandemic on your tomato vine, you have to introduce the pathogen to the tomato. One example of the introduction of a pathogen to an unexposed population was when Europeans showed up in the Americas with smallpox. The native population had not been exposed to smallpox, which caused widespread death and misery. But it is only fitting to point out that the Native Americans introduced tobacco to the rest of the world. Karma!

Any germaphobe would appreciate the best place to live if you want to avoid viruses, bacteria, and fungi would be outer space or another planet, far away from the source of the germs. Are Elon Musk and Jeff Bezos germaphobes? Just wondering...

Back to our crowd of aphids, they are not likely to catch the equivalent of an insect cold, let alone a pandemic, though such things exist. For example, members of the family of viruses called Baculoviridae feed on specific groups (genus and/or species) of insects. Infected insects will get a shiny, oily appearance and just hang around limply. In the end, the infected host will rupture releasing fluid filled with the pathogen. Good thing that does not happen with the common cold in humans! Put Timmy in the bathtub, he might rupture! Sounds like the premise for a SciFi channel movie.

There are obstacles in the way from weaponizing Baculoviridae to control insect pests.

Find the species that controls your pest. Baculoviridae is a family. A family is a group of genera, and each genus has individual species. So you need to find the species of Baculoviridae that can kill your species of pest. Not an easy task, but with the advent of genetic engineering, it is possible to find a close fit, a pathogen that kills another, closely related species and then modify its genome to kill the genus, not just the species.
Growing the virus. In order to spread the virus to your crop, you need to mass produce it. This requires you either raise it in the insect host, or a related cell line to be the host for the pathogen of that insect. If you have read or seen the movie "The Immortal Life of Henrietta Lacks" you may know that creating cell lines is difficult work. Rear the host, infect it, let it ooze out, and then collect the ooze, might be a better method.
Deploying the virus. The target insect needs to consume the virus. Viruses do not last very long in sunlight, so there is research being done to bio-engineer these viruses to be more resistant to UV decay. The Baculoviridae are tougher than a normal viruses, the viruses are also one of the largest in size.
Expense. In general it is a lot cheaper for a farm or an agricultural business to use organophosphorus nerve agents related to sarin such as the insecticides malathion or pyrethrin.

India currently researches and produces Baculoviridae products against army worms. The United States Forestry Service has produced Baculoviridae to fight Gypsy Moths.

It is a good thing that virus labs never have accidents, or do they?

A cautionary tale.

The coconut palm rhinoceros beetle had been accidentally introduced to a number of pacific islands. A large beetle, both the adult and larvae feed on coconut and oil palms. Without a natural predator, they were destroying the crops. Alois Huger, an entomologist from Germany was hired to find a solution. He found in the oil palms in Malaysia a natural pest of the coconut palm rhinoceros beetle, a virus. It was introduced to the Samoan Islands and was a success. However, thousands of miles away, in Korea, lived a different beetle, the Japanese rhinoceros beetle. They are raised on farms as pets for children, medicinal purposes, and fighting. Yep, you can gamble on the results of two beetles fighting. See Article.

So you can imagine the panic in the fighting pits when news spread of a virus, identical to the virus released in Samoa, had wiped out the Japanese rhinoceros beetle larva on their farms. Though the virus had been released to target the species of palm rhinoceros beetle, the Japanese rhinoceros beetle, a different species was collateral damage.

Let us hope that a future scientist wishing to create a virus to eradicate mosquitoes doesn't target another species, like Homo sapiens. If that happens, we would not have to worry about full-filling Harry Harrison's vision in Make Room! Make Room!

addendum: My favorite Harry Harrison book was Bill, the Galactic Hero

Make Room! Make Room! The movie: