Further drafting of the guidance on risk assessment and risk management of LM mosquitoes

I would like to remind the group of several points concerning mosquitoes and mosquito-borne pathogens.

First, there is no evidence that mosquitoes represent a keystone species in any of the tropical zones where they are primary targets of strategies proposing to use genetically-engineered mosquitoes. I realize that the absence of information is not conclusive, but their biomass in most places (except perhaps in Arctic and Alpine niches, where they are not targets of genetic intervention) makes it unlikely that they are the principal food source for other animals.

Furthermore, most mosquitoes that are major threats to humans are either invasive species (Aedes aegypti) and/or highly-adapted to living in or near human habitations and feeding on people. They are not representatives of pristine niches, but are concrete evidence of anthropogenic alterations of the environment. Thus, removing them from the environment is not a disruption of a "natural" ecology. Indeed, Aedes aegypti is well-adapted to living in large urban centers, and dengue virus epidemics are intitiating in these regions.

With respect to the comments in the Evolutionary Responses section of the Draft Outline, the ability of mosquitoes to transmit novel pathogens, with one exception (Aedes albopictus and Chikungunya virus), is not the general trend. For example, the range and extent of culicine mosquitoes overlaps in many places the distribution of anopheline species and human malaria parasites. Yet, over the many thousands of years of overlap, no culicine has been selected to transmit human malaria. Conversely, no anopheline transmits the viruses causing yellow or dengue fever. There is a natural experiment here that provides evidence to support the conclusion that there must be significant barriers that prevent mosquitoes from easily transmitting novel pathogens. These circumstances are not likely to change due to the presence of a transgene. Thus, the statements in the Draft Outline that mosquitoes "evolve to regain competency, or acquire new or enhanced competency of another disease agent" is not supported. Furthermore, with respect to the comments on "Disease agents" evolving to "become more virulent", increased virulence is not the general trend in the evolution of pathogenic agents. Indeed many studies and analyses have argued and provided evidence for the opposite. The better adapted the pathogen, the less virulent it becomes. That dosn't mean we don't see variations in virulence, but it is not a true statement to claim that evolution is selecting for increased virulence.