Mississippi used to be host to three sibling species of Anopheles
quadrimaculatus. They are still here but their names have
been changed. We now have:
Sibling species A = Anopheles quadrimaculatus
Sibling species B = Anopheles smaragdinus
Sibling species D = Anopheles maverlius
In 1990, 1992, and 1993 the Entomology Department of Mississippi State
University conducted statewide Anopheles quadrimaculatus collections
and identified sibling species by using starch gel enzyme electrophoresis.
We also found Anopheles crucians and Anopheles punctipennis, but this
study focused on the "quads." ("Quads" refers to the four dots on each of
their wings.
The following maps and files summarize the results of our
identifications.(1)
Computer Generated Frequency Contours
Anopheles quadrimaculatus Say
Manually Generated Frequency Contours
Anopheles quadrimaculatus Say
(Google Earth was used preparation of this map.)
The manually drawn map on the right started from Figure 1 in the
July 1993 Semi-Annual Report for the Ricelands Mosquito Management
Program(1). The map shows the following rivers. Little Sunflower (West
central - incomplete), Yazoo (West central - incomplete), Big Black
(West central), Pearl (South central), Leaf (Southeast), and the Tennessee
- Tom Bigbee Waterway (Northeast). (More rivers to come!)
In an insecticide resistance study, which was run
concurrently with the statewide survey, we found that An.
quadrimaculatus sibling species A was much more resistant to Malathion
and Permethrin than were sibling species B and D. In this writer's opinon,
the sibling A species "hot spots" at (a) the Pearl River in down-town
Jackson and at the Yockanookany River on the southeast edge of Kosciuscko,
may have been caused by that resistance.
The Ruben Morgan Rodeo grounds, at the eastern edge of the state, may
be another hot spot but improved plotting of the data points [and one
re-averaged point] makes that look less probable. The 95% value, the next
point north of the Rodeo, was earlier calculated as 90%.
Most of the data points on the original manually drawn map corresponded to
county centroids (with a degree of eyeball inaccuracy). These have
now been replaced with actual collection site locations.
ms-aq-90.txt Sibling species by collection site, 1990. ms-aq-92.txt Sibling species by collection site, 1992. ms-aq-93.txt Sibling species by collection site, 1993. gen1.txt (143 kilobytes) ASCII file used as an aid in
species identifications. alleles.htm Table of starch gel electrophoretic allele mobilities. alleles.gif
Graph of starch gel electrophoretic allele mobilities. ms-anop.xls Microsoft Excel Summary Data File for 1990-1993.
Field and Laboratory Personnel Involved
James Mallet (P.I.), Robert Fritzius, Sonny Ramaswamy,
Michael Caprio, Titiya Chittihunsa, Huang Jai Xing
The sibling species frequencies given in files
ms-aq-90.txt, ms-aq-92.txt, and ms-aq-93.txt, above, were used in a 2004
United States Anopheles quadrimaculatus complex study(2) published by
the U.S. Centers for Disease Control and Prevention.
References
(1) Sonny B. Ramaswamy and Robert Fritzius, Semi-Annual Report for the
Riceland Mosquito Management Program, 1 January - July 15, 1993. Submitted
Dr. Jim Olson, Department of Entomology, Texas A & M University, College
Station, TX.
