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Florida Medical Entomology Laboratory

Florida Medical Entomology Laboratory

Florida's Mosquito Control Research Program: Scant Resources and Missed Opportunities

The State of Florida mosquito research program is an important component of Florida mosquito control. This program annually establishes research priorities and awards State funds on a competitive basis. It is a difficult job for those on the Florida review panel. The panel works hard to recognize proposals based on impact, need, and chance of success. This is all done in a climate of scant and precious research dollars. The members of the review panel deserve our thanks.

During the most recent review of proposals, some reviewers believed that a project to investigate a possible species complex of Culex nigripalpus in Florida was not of high priority because it was more of academic interest. An honest assessment perhaps, certainly arguable and deserving discussion. The fact that I disagree might be expected. In an era of scarce research funds there will be important projects that cannot be supported. However, the failure to support the C. nigripalpus project also illustrates that the current inadequate funding for the mosquito research program results in too many missed opportunities, opportunities that are critically important if we are to move Florida Mosquito Control programs into the 21st century. Elsewhere, (Buzz Words Apr/May 2000) I advocated that we must continually discuss Florida's mosquito research needs to ensure that essential projects are supported.

Once a species is established by reproductive isolation, it essentially becomes a separate evolutionary unit. The exchange of genes through reproduction prevents populations within the same species from diverging. Any gene exchange reduces population divergence in the species characteristics. There may still be geographic variation within a species, however the extent of genetic differentiation is substantially less compared to differentiation that accumulates between species. The inability to share genes creates genetic discontinuity and results in differences between species. For example, pesticide resistance could not spread to another species by gene exchange.

So why should Florida mosquito control care if there is a C. nigripalpus species complex? Such a finding would have a profound impact. More than one C. nigripalpus species would mean there is greater differentiation in suites of characters as compared to population divergence in a single species. The ranges of all the species would have to be characterized. Where are the species? Do they overlap? What are their relationships? Where they do overlap? Are there hybrids? What is the impact of hybrids? The impact on our understanding of different C. nigripalpus traits could be enormous. Do the species share traits? What are their behaviors? Are the species equal pests? Have they all been targeted by mosquito control? Should each species be targeted? Do they emerge at the same time of the year? What is their vector capacity for SLE, EEE and WN viruses? Which species is the more efficient vector? What hosts do they prefer? What are their roles in virus amplification? How do they respond to mosquito control operations? What about insecticide resistance differences? On and on, based on the finding of different species.

The finding by Falleroni beginning in 1926 that Anopheles maculipennis is a species complex led to finding that only certain species in the complex are malaria vectors. "Anopheles without malaria" is one of the great achievements in medical entomology. The same is true for the Anopheles gambiae complex. Then there is the Culex pipiens complex. The identification and characterization of species complexes is essential for effective mosquito and disease control. Is the proposal, based on Dr. Richard Darsie's preliminary data, that there is a Florida C. nigripalpus species complex, only of academic interest? Hardly.

Why is Florida missing opportunities to obtain essential information? Look at the projects that did not receive support listed in this issue of Buzz Words. This work will not be accomplished. This information will not be available as part of our control armament in the next 1-3 years. Our colleagues on the review panel are forced to make decisions on research priorities using inadequate funds. Important proposals are not supported. It is not the research proposals; it is not the review committee. The fault lies in an inadequate funding level. The State budget to support the mosquito research program is currently $250,000 per year. A large sum of money. Florida mosquito control is thankful to have it. However, 13 years ago the program was supported by $500,000 per year. The current annual level has remained at $250,000 for the past decade. Adjusted for 3% inflation per year, the program would require ca. $380,000 annually to be at the same level of support as 1991; 4% inflation would require $433,000. At 3% annual inflation the original $500,000 would require ca. $700,000 in 2001 to equal 1989 dollars. In the climate of increasing funding for vector-borne disease control in Florida, the potential impact of SLE, EEE and WN, is it not appropriate to increase the Florida mosquito research program as well?

Important research issues are left undone despite the best efforts of the review committee. We are not moving forward against C. nigripalpus. We will not have information from the other listed projects. Missed opportunities. We must address mosquito research funding in Florida. We can and must do better. As always I welcome your comments.

Walter J. Tabachnick, Ph.D. - Retired
Florida Medical Entomology Laboratory