Malaria Vector Control: Azadirachta indica as a

sustainable tool for integrated Mosquito Larvae Management

Gordon Sevee

Neem Tree, Azadirachta indica

•Family: Meliaceae (Mahogany)•Distribution of Azadirachta indica: Found in 78 countries world-wide, global occurrence 64 to 91 million trees, mainly South Asia, Sub-Saharan Africa, found throughout Mali, including village of Sanambele •Description: Evergreen, broad-leafed tree growing up to 30m in height, produces 99 biologically active compounds with wide range of effects:

-larvicidal, insecticidal, repellent, antifeedant, antipyretic, contraceptive, and antiparasitic

-Authorized by EPA on food and nonfood crops

Moser, Gerald (1996), Status Report on Global Neem Usage,

Pesticide Service Project, PN 86-2588 GTZ, Germany, pp 39.

http://www.africanmarketsquare.ca/neemtree_b.jpg

http://host.webinnovation-host.net/%7Eeacircle/images/znz771.jpg

Sanambele, Mali

Has identified malaria as number one problem they face (Kante, Dunkel, Williams, Margo, Camara, 2009)

High rates of transmission/mortality in children

– 7 Children died in 2007– 5 Children died in 2008– Population approximately

1000 Places a social / economic

burden on village

Sanambele and A. indica Sanambele farmers are

already familiar with neem and its potential

Farmers have used a leaf slurry for food crop application (Gamby and Dunkel 2001)

Neem trees found throughout village and surrounding fields

DDT and pyrethroids applied to preharvest food crops were replaced in late 90’s by neem leaf extracts made by Sanameble farmers (Moore et al. 2001)

Anopheles Mosquito and Sanambele Without mosquitoes

malaria is not spread Adult females bite people

with malaria, then transmit Plasmodium to healthy individual by later biting them

Mosquito populations highest during rainy season (June-August) when many ephemeral breeding pools are available and humidity is high.

Clulex pipiens Rearing

Eggs transferred to 1.4L Pyrex pan with 300mL of dH20, 9mL Tetramin diet solution

Rearing pan placed in mosquito cage in environmental control chamber, 78F, 80% R.H., 14:10 hour light:dark photoperiod

Larvae were treated similarly

A. indica Leaf Slurry Formation

14 Leaflets were removed from a compound leaf and placed in a mortar and pestle

Leaves were ground 20 minutes20 mL dH20 was slowly added while

grindingSlurry was transferred to a freezable

container (40ml glass vial) frozen for later use

Developing Bioassay Procedure

Hypothesis tested: Larvae exposed to neem leaf slurry will show irregularities in locomotion and significant mortality after exposure to neem slurry.

Control: Larvae placed in small petri dish with 20mL rearing tray solution

Neem Slurry: Larvae placed in small petri dish with 10mL neem slurry and 10mL rearing tray solution

Developing Bioassay Procedure

Locomotion observations were made every 15 min for the first two hours

After the first two hours they were examined every hour for 4 more hours

Responses to probing and wind were observed in control and slurry dishes

Response to Neem Slurry Exposure

- All larvae exposed to 50% concentration were moribund (abnormal locomotion, weak probing response) and 25% mortality after 24 hours exposure-All control larvae displayed regular locomotion, vigorous probing response and 0% mortality

Probit Analysis

3 treatments with 30 individuals per treatment

Little to no control mortalityEven distribution (not 0 or 100%

mortality)50, 75, and 100% neem slurry

concentrations will be used

Lab to Sanambele

Constructing a model for a bioassay to be tested in Bamako, Mali at Anopheles rearing facility, University of Bamako Medical School, Malaria Research/Training Center

Village adoption of neem slurry as part of sustainable, integrated Anopheles (malaria vector) management

Eventual replacement of Bacillus thuringienesis var. israelensis, – Sustainable option eliminates need for foreign

financial support, completely produced in village, without fear of resistance development.

Above: Mosquito dipper and collecting pan

Right: looking for signs of larvae

Acknowledgements

•USDA CSREES Higher Education Grant, #4W01809. New Paradigm for Discovery Based Learning: Implementing Bottom-up Development by Listening to Farmer’s Needs and Using Participatory Processes with Holistic Thinking, Montana State University lead institution, Dr. F. Dunkel, P.I.

•Montana Agricultural Experiment Station #161 (F.Dunkel, P.I.)

• I would like to acknowledge collaboration of the Sanambele Women’s Association and the men and women farmers engaged in this ambitious hope to erradicate malaria from their village.

References:

RebeccaLGianotti*, et al. Efficacy of local neem extracts for sustainable malaria vector control in an African village. Malaria Journal 2008, 7:138

Grunewald, J., A. Vollmer. 2000. Malaria-control with neem products in the Mopti region in Mali, West Africa. Proceedings of the 9th Workshop, Practice Oriented Results on Use and Production of Neem– Ingredients and Pheromones, Hohenheim, Germany. Pp. 173-174.

Savory, Allan. Holistic Management: A New Framework for Decision Making. Island Press: Washington, DC, 1999.

Thrupp, Lori Ann, et al. Farmer First: Farmer Innovation and Agricultural Research. Bootstrap Press: New York, NY, 1989.

Abera, Eferem, et al. Farmer Participatory Research in North Omo, Ethiopia. Internation Institute for Environment and Development, 1991.

Ayittey, George. Africa Unchained. Plagrave MacMillan: New York, NY, 2005.

Sachs, Jeffrey. Common Wealth: Economics for a Crowded Planet. The Penguin Press: New York, NY, 2008

Okumu, Fredos, et al. Larvicidal effects of a neem oil formulation on the malaria vector Anopheles gamniae. Malaria Journal, 2007, 6:63