Abstract In 2002 – 2003, a survey of 120 small-scale maize farmers was conducted in four hillside communities in SE Honduras to quantify the role of pesticide information sources, local diffusion networks and social connectedness in influencing farmer knowledge and adoption of IPM. In each community, IPM training recipients and opinion leaders were identified and their role in affecting local spread of agro-ecological and pest management information was assessed. Farmers reported various sources of pest management advice, with friends and relatives, outreach agencies and pesticide sellers frequently cited. Information on pesticide alternatives for management of a key maize pest, the fall armyworm Spodoptera frugiperda Smith, was gained mainly through interpersonal communication channels. IPM training recipients were socially well connected and up to 60% of them were consulted by their peers. Farmers connected to training recipients had a better appreciation of arthropod natural enemies and, in certain communities, knew more about pesticide alternatives and natural enemy conservation methods. Information on certain technologies (i.e. manual control, sugar-water application to attract arthropod predators) was shared between farmers, while knowledge of others (i.e. botanical insecticides) was largely restricted to training recipients. In communities that were socially well organized and frequented by outreach agencies, selected information appeared to diffuse beyond trained farmers. Implications for the design of IPM extension packages are discussed. Keywords: Integrated pest managementtechnology transfersocial network analysisknowledge systemsinformation sources Acknowledgements R.L. Koch, J.W. Bentley and P. Van Mele provided helpful comments that improved the quality of the manuscript. P. Doyle assisted in defining this project and provided guidance and support throughout our research. J.W. Bentley provided invaluable help with the design of survey instruments while C. Zurita, N. Gamero and G. Aguirre facilitated the initial stages of farmer surveys in each community. This study was supported by a Purdue Research Foundation Fellowship grant (PRF-grant 6903757), a Global Initiative travel grant, a Ross Fellowship and the Department of Entomology, Purdue University. We would also like to thank the Socio-Economics and Environment Department (DSEA) and the Plant Protection Department (DPV) at the Panamerican College of Agriculture 'El Zamorano' (Tegucigalpa, Honduras). This is Purdue Agricultural Program number 2006 – 18037.