A participatory approach to assessing landscape complexity impacts on specialist pests: Can traditional Andean fallow farming reduce the establishment of Guatemalan potato moth (Tecia solanivora)?

While landscape complexity can have strong positive effects on arthropod natural enemies, it remains unclear whether surrounding semi-natural areas can limit the establishment of specialist pests in crops. In this study, we assess whether traditional farming practices in the Venezuelan Andes that improve landscape complexity can reduce population densities of a specialist potato pest, Tecia solanivora. Participatory arthropod monitoring was conducted in 2011 in a smallholder farming community in Misinta, Venezuela to determine: 1) T. solanivora and arthropod natural enemy population densities in 21 potato cropping systems and 2) land use, fallow rotation practices, and landscape complexity across the farming community. Our findings indicated that, while T. solanivora responded negatively to non-cultivated natural and semi-natural areas in the surrounding landscape, they responded positively in landscapes featuring a high proportion of long fallow habitat. This study shows that landscape complexity effects can be idiosyncratic, and that nuanced approaches to understanding the effects of surrounding semi-natural habitat on specialist herbivores are needed.