An entomologist doesn’t usually go around calling insects “bugs.” Such a person would reserve that term for a particular group of insects, specifically the order Hemiptera, which includes aphids and leafhoppers. Boxelder bugs (Boisea trivitatta) are common here in the American West and they are “true bugs” in that sense. But we ordinary mortals use “bug” for anything vaguely insectoid that flies, buzzes, crawls, bites and generally gives us the creeps. We are mostly lucky, those of us that live west of the 100th meridian and north of the Mexican border, in that our semiarid climate reduces the incidence of insect-borne diseases.
The biggest killer of all is the mosquito. One species, Aedes aegypti, is responsible for transmitting the virus which causes dengue fever. Tens of millions of people are infected yearly with dengue and it is fatal in one to five percent of the cases. There are treatments but no cure, and some experimental vaccines are being tested. We don’t hear much about dengue fever in the States as it mostly affects people in tropical and sub-tropical regions. It is endemic in Puerto Rico, for example, and has shown up in the Florida Keys, but places like Brazil and Malaysia have climates more suited to large mosquito populations.
There was a time when yellow fever was a serious problem, even in the States, and one of the most dangerous infectious diseases worldwide. The same Aedes mosquito was responsible. We have a vaccine now, and of course the more obvious solutions of mosquito control like liberal use of insecticides. Draining and clearing swamps, marshes, and other wetlands also reduced the mosquito hordes. This is what we do to combat dengue fever. The problem is that destroying mosquito habitat also means destroying the habitat of all the other wetland plants and animals! And mosquitoes reproduce rapidly and have developed resistance to the insecticides once used to control them. Many people are also concerned about the accumulation of these poisons in the environment, perhaps contaminating the water and food supply, and killing other creatures not targeted, a sort of ecological collateral damage.
Oh, what to do? Like I said here in the semiarid West we don’t have a lot of issues with mosquitoes and their blood-borne pathogens. But in an increasingly global world the spread of tropical diseases to new areas is happening. And with the recent threat of the Zika virus even the US Congress is taking notice. Yes, Zika is spread by the Aedes mosquito. In fact, the US State of Hawaii has declared an emergency over Zika. Makes you want to go out and stomp those little bastards, doesn’t it?
Naturally there are some creative solutions. One is called the Sterile Insect Technique (SIT) which involves releasing factory-altered males into the native population. They are sterile and the mating with females produces no offspring or infertile offspring. This method eliminated the screwworm fly problem in the US decades ago. The usual technique is irradiation of the larvae or pupae. Anti-nukers would probably get on board with this “peaceful use” of atomic energy, don’t you think?
SIT requires huge numbers of such altered insects. The radiation technique is not very precise and the carriers have a number of “lethal genes” that they pass on to the offspring. Dozens of countries have used this practice for decades, however, and SIT has been used effectively against the Mediterranean fruit fly (the “medfly”), for example. That has required the production of about 20 billion sterile males from global insect-rearing facilities per week. Wow! Billions of genetically-altered bugs in the environment! Who knew?
But wait, there’s more. Turns out that a company called Oxitech has created a sterile male Aedes mosquito using genetic engineering. This critter has the advantage of being mostly “normal” and “healthy” and can successfully compete with the “natural” males and pass on their death-gene to the offspring which then fail to grow properly and thus die. Apparently mosquitoes don’t hold up as well to irradiation as flies and other bugs and the SIT strategies weren’t as effective with the weakened individuals being released. So the biotech geniuses came up with a more narrow, gene-specific approach, much like a targeted rather than a broad-spectrum antibiotic. This new lab-made mosquito has been tested in the field and shown to effectively reduce the populations of dengue-carrying Ae. aegypti.
Just this morning I read a story on the BBC website (a marvelous place for news, by the way) which said that the World Health Organization (WHO) backs trials of GM mosquitoes for fighting the Zika virus. We get a lot of GMO talk here in the States but it mostly has to do with crops, particularly corn. We argue over safety and labeling and whatnot. We even have a local Oregon county that has banned the use of GM crops. Folks don’t want to eat GMO-based food, it seems. Recently the FDA approved the production of GM salmon for human consumption. Naturally this has created a lot of controversy as it is a big step up from something like Bovine Growth Hormone which is a product of recombinant DNA (molecular cloning) technology but not an actual modified organism. A number of US retailers will not sell milk from BGH-treated (more properly rBST, recombinant bovine somatotrophin) cows, and there has been a nation-wide pushback against the product.
Much of this is driven by a fear, a legitimate one in my mind, that we have moved too far from our food supply. Only two percent of Americans are farmers and most of us live far from where food is produced. In the rural West farms and ranches are part of the daily scene but city and suburban dwellers are increasingly isolated from their life-sustaining connection to the land. The factory farm is the new model and the mass-production of crops and livestock is the way of the future. After all there could be nine billion mouths to feed by 2050! Americans and citizens of other wealthy countries are more and more interested in organic foods and small-scale, community-based agriculture. While these are welcome trends, they are mostly confined to regions where people have a high standard of living already and thus can be picky about what they eat.
In the poorer regions of the world where Zika and dengue are real threats and where the food supply is not as consistent there is less resistance to new technologies. To be fair, many of these places also lack robust, democratic institutions, human rights, and independent media so even if people had concerns they might not have the means to act on them. Franken-bugs like the genetically engineered mosquito are actually welcome, though, as the disease is a greater threat than the potential environmental impacts. Thus it does not surprise me that WHO has pushed for trials of the new bug (known as OX513A) to fight Zika, as it has the additional benefit of perhaps containing dengue as well.
Technology is not good or bad. The first caveman (or cavewoman) who figured out how to make a knife out of a rock and used it to carve up an animal kill and feed the family could also have just as easily sliced up their neighbor with it and taken their food. People are capable of great acts of love and kindness as well as great acts of treachery. It is easy to mistrust corporations and view their achievements with suspicion. Pick out ten people at random and I’ll bet at least six of them will have a very negative view of Monsanto, for example. But that should not blind us to the remarkable advancements that have come as well. Dengue and Zika aren’t coming to the State of Jefferson anytime soon so I doubt we have to worry about OX513A “infecting” our local mosquitoes. Not that we have all that many!
Despite the fears of Franken-crops and Franken-fish and Franken-bugs the innovations are not going away. We haven’t blown ourselves up with our nuclear weapons yet, although we certainly could, and I don’t think we’ll go all Jurassic Park on ourselves, either. Not to say that we aren’t capable of messing things up, we are. It’s just that the solutions to global problems like hunger and disease are complex and multi-faceted and will require an integrated approach with a variety of tools at our disposal. So I’m rooting for OX513A. I hope those little buggers wipe out Ae. aegypti. I know that technological solutions alone are insufficient, and there are dangers in relying on such “fixes” when much of the problem is social, economic, and institutional. But damn if this isn’t a fantastic opportunity to learn as well as a real chance to help those who are much worse off than we are!
p.s. Just for the record, I’d eat a GM salmon. Maybe the new genes will give me some cool mutation like super-powers (or at least a better jump shot). Just kidding, I know it won’t do that. Seriously, I don’t worry about GMO in my food supply. I can think of a hell of lot more frightening things than that.