Comparison of the temporal efficacy of Aquatain surface films for the control of Anopheles arabiensis and Ochlerotatus caspius larvae from Sudan

Aquatain Mosquito Formulation (AMF) is a surfactant that spreads across
the surface of water bodies to produce a monomolecular film. This study
experimentally evaluates the temporal efficacy of AMF against aquatic
stages of Anopheles arabiensis and Ochlerotatus
caspius under laboratory conditions. Using the recommended
application does of 1ml/m2, a large species specific difference
in the median lethal time for L3-L4 larvae was observed. The
median lethal time to 50% mortality (LT50) and 90% mortality (LT90) was
1.3 hours, 95% CI [1.2, 1.4] and 3.8 hours, 95% CI [3.6,
4.0] respectively for Oc. caspius. The
corresponding values for An. arabiensis was 8.1
hours, 95% CI [7.3, 9.0] and 59.6 hours, 95% CI [48.5,
76.2]. Based on data from published laboratory studies for a
total of seven mosquito species drawn from four genera results in the
following three groups, [LT50=1-2 hours, Culex
quinquefasciatus, Ochlerotatus caspius] [LT50=8-24,
hours, Anopheles minimus, Anopheles arabiensis,
Anopheles gambiae s.s] and [LT50 =72-143
hours, Anopheles stephensi, Aedes aegypti,]. In
all experiments 100% mortality was achieved given sufficient time. The
potential relevance of mortality rate estimates in the context of other
studies on the use of monomolecular films for the control of
malaria and arbovirus diseases is discussed.