1. Jabatan Sains Bioperubatan Departmentof Biomedical Science
Larvicidal Activity of
MousticideTM Rice Husk and
Wettable Powder Formulation
Against Anopheles Sinensis
Testing Performed by:
Saiful Azlan Nordin
Noor Shareena Aisha bt Abdul Khalid
Aimi Syamima bt Abdul Manap
Murni Binti Soed
Under the Supervision of:
Professor Dr. Hidayatulfathi Othman
University Kebangsaan Malaysia

2. Jabatan Sains Bioperubatan Departmentof Biomedical Science
INTRODUCTION
Trypsin-modulating oostatic factor (TMOF), a mosquito decapeptide,
terminates trypsin biosynthesis in the mosquito gut. The hormone is secreted from
the ovary, starting 18·h after the blood meal, circulates in the hemolymph, binds to a
gut receptor and stops trypsin biosynthesis by exerting a translational control on
trypsin mRNA [6]. Feeding of TMOF mixed with the blood meal to female Ae. aegypti
stopped trypsin biosynthesis and inhibited egg development in the ovaries [7].
Research conducted using TMOF in combination with Bacillus thuringiensis
israeliensis (Bti) against Ae. aegypti 1st instar larvae in the laboratory was found to
improve the activity of these product by giving quick mortality within 1 hour treatment
with prolonged residual effect (no larvae survived) against all larval stages up to four
weeks following treatment [8]. TMOF-Bti is the combination of TMOF and Bacillus
thuringiensis israeliensis which showed an increased of efficacy in killing mosquito
larvae. TMOF-Bti developed into a finished product, Mousticide™, with formulations,
a granular formula on rice husk and a wettable powder. Various studies have been
conducted to prove the efficacy of Mousticide™ both in the laboratory and in the field
against Aedes aegypti, as an initiative to move forward in the prevention of
mosquito-vectored diseases. Testing of the larvicidal effects of Mousticide™ on
Anopheles sinensis was carried out to combat another vector borne disease -
Malaria. Malaria is common in sub-Saharan African countries, and WHO states that
nearly 90% of the deaths in Africa are caused by Malaria. With this new technology,
we hope that the number of victims of malaria can be reduced.

3. Jabatan Sains Bioperubatan Departmentof Biomedical Science
OBJECTIVE
1. To assess the efficacy of Mousticide™ in wettable powder formulation and rice
husk formulation against third instar larvae of Anopheles sinensis.
2. To compare the larvicidal activity between Mousticide™ n wettable powder
formulation and rice husk formulation to Abate™.
PROCEDURE
The bioassays for Mousticide™rice husk and wettable powder against Anopheles sp.
were conducted using WHO standard protocols (WHO, 1981). Twenty (20) second
instar larvae are introduced into a fresh paper cup containing 200 ml distilled water
and the different larvicides added at the desired concentrations. No larvicide
additions were made to the control cups. A minimum of three replicates are made
for each formulation. The concentration of rice husk and wettable powder used in
this test was 5 mg/200 ml and 1 mg/200 ml respectively. Abate™, a “gold standard”
positive control chemical larvicide was assayed in parallel using the recommended
WHO dose of 0.012mg/L. As a control, 200 ml of distilled water only was used in this
study. Twenty (20) second instar larvae of Anopheles sp. were transferred from the
breeding tray into the all the paper cups. Data were recorded at post one hour, 24,
48 and 72 hours to assess the mortality rate of the larvae

4. Jabatan Sains Bioperubatan Departmentof Biomedical Science
RESULTS AND DISCUSION
Chart 1 shows the comparison of mean larval mortality percentages using
Mousticide™ wettable powder formulation and rice husk formulation, to Abate™.
From the chart we can see that in 1 hour, mean larval mortality was showed by
Mousticide™ in rice husk formulation was 15%. After 24 hours, the mean larval
mortality increased to 100%.
Mousticide™ in wettable powder formulation did show any larval mortality in 1
hour after the application. However, after 24 hours of application, the larval mortality
recorded were 96.7% and increase to 100% after 72 hours.
Surprisingly, Abate™, a neurotoxic chemical pesticide commonly used as a
mosquito larvicide showed only limited larvicidal activity at 24 hours (3.3% which
gradually increased with time). Abate™ would be expected to rapidly cause
mortality of the mosquito larvae based on its neurotoxic mechanism. The prolonged
time required for Abate™ efficacy suggests that the mosquito larvae are able to
forestall its toxic effect (resistance). The fact that resistance is present in a
laboratory-reared mosquito population is disturbing as laboratory-reared strains are
commonly used to assess biological activity of test and commercial larvicidal
compounds.
In this study, Mousticide™ was compared to Abate™, a gold standard chemical
larvicide used in controlling vector borne diseases caused by mosquitoes worldwide.
Compared to Abate™, it was demonstrated that Mousticide™ can effectively control
Anopheles sinensis, a vector for malaria. Mousticide™ was able to provide 100%
larval mortality of Anopheles sinensis in 24 hours while Abate™ only showed 3.33%
larval mortality. In our previous study, Mousticide™ gave 100% mortality against
Aedes aegypti in 24 hours after application, both in the laboratory and in the field. A
field trial in a dengue endemic site at Gombak, Malaysia, demonstrated that a single

5. Jabatan Sains Bioperubatan Departmentof Biomedical Science
application of Mousticide™ rice husk was able to control dengue for 5 months. The
results from the present study suggest that Mousticide™ can also be an effective
agent to control Malaria, a deadly disease vectored by Anopheles sp. This study
demonstrated that Mousticide™ is very effective against the larvae of Anopheles
sinensis and can be an important tool to fight malaria. From the results, we conclude
that both Mousticide™ in wettable powder formulation and rice husk formulation are
very effective against the third instar larvae of Anopheles sinensis compared to
Abate™.
The results of Mousticide™ on the larvae of Anopheles sp demonstrates that it is a
very effective larvicide against various species of mosquito larvae which are
important disease vectors.

6. Jabatan Sains Bioperubatan Departmentof Biomedical Science
Chart 1 : Mean Larval Mortality Percentages Against MousticideTM and AbateTM
CONCLUSION
The result from this test allows us to conclude that Mousticide™ in rice husk and
wettable powder formulation are very effective against larvae of Anopheles sinensis.
ACKNOWLEDGEMENT
We would like to acknowledge Entogenex Industries Sdn. Bhd. for providing the
research grant for this study and Vector Control Research Unit, Universiti Sains
Malaysia for providing Anopheles sinensis larvae and facilities to do this study

7. Jabatan Sains Bioperubatan Departmentof Biomedical Science