Insects could be used to spread infectious viruses that have been engineered to genetically modify food crops directly in planted fields – in effect creating a weapon for use in biological warfare – if a research program funded by an agency of the United States Department of Defense is allowed to continue, according to a report in the journal Science.
The report, by scientists from Germany and France, says the US program, known as “Insect Allies” and funded by the US Defense Advanced Research Projects Agency (DARPA), has potential “regulatory, biological, economic, and societal impacts”, while also presenting a “very limited capacity to enhance US agriculture or respond to national emergencies in either the short or long term”.
DARPA’s own description of the program can be downloaded here.
One of the key concerns of the researchers, which include geneticist Robert Guy Reeves, from the Max Planck Institute for Evolutionary Biology, in Germany, and law professor Silja Voeneky, from Germany’s University of Freiburg, is the use of insects to spread the virus, rather than the more common overhead spraying.
“This is genetic engineering through horizontal transfer, as opposed to vertical inheritance,” they write, adding that dispersing such horizontal environmental genetic alteration agents (HEGAAs) into ecosystems has “profound” implications.
“As a result, the program may be widely perceived as an effort to develop biological agents for hostile purposes, and their means of delivery, which – if true – would constitute a breach of the 1972 Biological Weapons Convention,” their report says.
Horizontal gene transfer refers to the movement of genetic material between unrelated individuals. Vertical gene transfer is the passing of genetic material from parent to progeny.
The report notes that agricultural genetic technologies typically work by introducing laboratory-generated modifications into target species’ chromosomes. But the speed and flexibility of this approach are limited, because modified chromosomes must be “vertically inherited” from one generation to the next.
In an effort to speed up the process, the DARPA program aims to use insects to disperse infectious genetically modified viruses that have been engineered to “edit crop chromosomes” directly in planted fields.
“It is our opinion that the knowledge to be gained from this program appears very limited,” write Reeves and colleagues.
“Furthermore, there has been an absence of adequate discussion regarding the major practical and regulatory impediments toward realising the projected agricultural benefits.”
The Insect Allies program was launched in 2016, reportedly backed by more than $US27 million in awarded research contracts. The report says that in July 2017, a consortium comprising the US Boyce Thompson Institute, the University of Minnesota, the University of California, Davis, and Iowa State University became the first organisation to announce it had been awarded a contract from DARPA to develop systems for insect dispersion of genetically modified viruses.
These are contracts for completion of a four-year work plan that will culminate in large-scale greenhouse demonstrations of the fully functional insect-dispersed virus approach, the report says.
The DARPA program’s stated aim is to help farmers manage agricultural concerns such as drought, frost, flooding, salinity, herbicides and disease. But the report authors say there has been “little public explanation” of how developments arising from the program might be applied to achieve the desired benefits.
Maize and tomato plants are reportedly being used in the current experiments, and dispersal insect species mentioned include leafhoppers, whiteflies, and aphids. The report says two research organisations funded by DARPA have publicly identified the target species for their experiments as maize – “a crop upon which hundreds of millions of people rely for their basic nutritional needs, mainly in Latin America and Africa”.
Recently Australian and US scientists were reported in the journal Nature Plants to have found a way to increase maize productivity by targeting the enzyme behind photosynthesis. That’s significant, they say, because they’ve been able to make an already good performer – and an important one – even better.
Reeves and his team say there are crucial flaws in the Insect Allies plan that greatly add to the prospect of it becoming weaponised.
The report includes a graphic description of what the authors regard as serious problems inherent in the insect-based infection plan. A genetically modified virus targets chromosomal genes essential for seed fertility in a particular crop variety, which is generally susceptible to genetically modified virus infection. The virus is assumed to be capable of infecting either seeds or meristems (tissue found chiefly at the growing tips of roots and shoots).
“The released virus-infected insects may survive longer than the DARPA stipulated two weeks, or may reacquire virus infection from plants,” the researchers claim.
Further, they write, it will not always be possible to confidently identify which plants or fields have been infected by the genetically modified virus, owing to inevitable uncertainty about insect movements and the susceptibility of crops to viral infection: “This would be a particularly critical problem in areas where seeds are produced for replanting.”
They say they have identified that “easy simplifications – and not elaborations – of the described work program could be used to generate a new class of biological weapon”.
Although routine agricultural use is prominently presented in most documents as the motivation for the DARPA program, the report says a secondary motivation is briefly acknowledged in some: “namely its use as a defensive response to unspecified ‘threats introduced by state or nonstate actors’.”
Crucially, the report says, all of the prominently hypothesised benefits to routine peacetime agriculture could probably be realised through basic crop spraying.
“It is therefore reasonable to ask, why mandate insect-based dispersion at all?” they ask.
The report continues: “it is our opinion that until DARPA provides suitably robust explanations for the necessity of mandating insect dispersion in routine agricultural or emergency applications, Insect Allies risks being widely perceived as an attempt to develop a means of delivering HEGAAs for offensive purposes.”
“To be clear,” the authors say, “it is not our contention that the Insect Allies Program is ill-conceived simply because it is a military-funded program … In our view, the program is primarily a bad idea because obvious simplifications of the work plan with already-existing technology can generate predictable and fast-acting weapons, along with their means of delivery, capable of threatening virtually any crop species.”
In a scathing criticism of the DARPA plan, the report offers this dire assessment: “Should this be accepted as the global norm for funding projects that enable such potentially hazardous directions of research, the best practices and rules, which have contributed to keeping our world largely free from the use of devastating biological weapons for over 60 years, may be seriously undermined.”
Reeves and colleagues conclude: “Reversal of funding for this DARPA project by the US Congress would not in itself close the particular Pandora’s box that HEGAAs or their insect dispersal may represent.
“Nonetheless, there is a compelling argument that nowhere has bold leadership for the benefit of humankind been more internationally reciprocated than in the control of the use, development, or stockpiling of biological weapons.”