Abstract:
BACKGROUND: Knowledge of the ecology and behaviour of a target species is a prerequisite for the successful
development of any vector control strategy. Before the implementation of any strategy it is essential to have
comprehensive information on the bionomics of species in the targeted area. The aims of this study were to
conduct regular entomological surveillance and to determine the relative abundance of anopheline species in the
northern Kruger National Park. In addition to this, the impact of weather conditions on an Anopheles arabiensis
population were evaluated and a range of mosquito collection methods were assessed.
METHODS: A survey of Anopheles species was made between July 2010 and December 2012. Mosquitoes were
collected from five sites in the northern Kruger National Park, using carbon dioxide-baited traps, human landing
and larval collections. Specimens were identified morphologically and polymerase chain reaction assays were
subsequently used where appropriate.
RESULTS: A total of 3,311 specimens belonging to nine different taxa was collected. Species collected were:
Anopheles arabiensis (n = 1,352), Anopheles quadriannulatus (n = 870), Anopheles coustani (n = 395), Anopheles merus
(n = 349), Anopheles pretoriensis (n = 35), Anopheles maculipalpis (n = 28), Anopheles rivulorum (n = 19), Anopheles
squamosus (n = 3) and Anopheles rufipes (n = 2). Members of the Anopheles gambiae species complex were the
most abundant and widely distributed, occurring across all collection sites. The highest number of mosquitoes
was collected using CO2 baited net traps (58.2%) followed by human landing catches (24.8%). Larval collections
(17%) provided an additional method to increase sample size. Mosquito sampling productivity was influenced
by prevailing weather conditions and overall population densities fluctuated with seasons.
CONCLUSION: Several anopheline species occur in the northern Kruger National Park and their densities fluctuate
between seasons. Species abundance and relative proportions within the An. gambiae complex varied between
collection methods. There is a perennial presence of an isolated population of An. arabiensis at the Malahlapanga
site which declined in density during the dry winter months, making this site suitable for a small pilot study site
for Sterile Insect Technique as a malaria vector control strategy.
