20Growing urban expansion results in the alteration of ecological processes (i.e. 21 predation) within trophic networks. Predation on herbivores is known to vary with the size 22 of the area covered in vegetation, successional stage, altitude, and the structure of the 23 predator community, but there are gaps in information regarding how this occurs in urban 24 and suburban environments. The purpose of this study was to determine whether the 25 predation pressure on artificial models of lepidopteran larvae varied with degree of 26 urbanization, type of substrate, and group of predators (birds or arthropods) in Cali, 27Colombia. Five hundred and eighteen artificial larvae were placed in two areas of the city 28 (urban vs. suburban) and in two types of substrate (leaf vs. stem) for 30 continuous days 29 and with two replications over time. Total predation was measured as the number of models 30 with evidence of attack by predators. The overall incidence of predation was 24.13%, and 31 was significantly higher in the urban area (63.20%) when compared to the suburban area 32 (36.80%). The leaf substrate was attacked significantly more than the stem (60% vs. 40%). 33The proportion of attacks carried out by birds was significantly higher (74.40%) than that 34 carried out by arthropods (24.80%). Together, these results suggest that the incidence of 35 predation varies with the disturbance caused by urbanization and by the type of substrate in 36 which prey organisms are found. In addition, the study confirms that birds are the main 37 controllers of herbivorous insects in urban environments. 38 [Introduction 42 The drastic transformation of pristine natural landscapes into fragments within urban 43 landscapes [1-2] causes changes in community composition, structure, abundance, and 44 trophic relations [3]. The size of these fragments of vegetation and the degree of 45 disturbance in the interior and surrounding areas affect the permanence of species that 46 require large continuous areas of habitats and particular food resources [4-6]. When species 47 disappear from a habitat, predator-prey relationships change and some species are 48 temporarily favored. For example, herbivore communities undergo rapid growth in habitats 49 where populations of its natural enemies are low or have disappeared due to human induced 50 changes [7, 9]. 51 Predation pressure varies both within and between habitats due to differences in 52 community and predator density, vegetation structure and complexity, and intensity of 53 anthropogenic disturbance [2, 10-11]. Compared to the interior, the edges and patches of 54 forest fragments are considered as areas of greatest predatory risk for many species [5, 8, 55 11, 12]. In forest clearings, herbivores and their predators are more abundant since these 56 sites show increased leaf and plant growth compared to the understory [8]. When 57 comparing forests with open and close canopies with rural, researchers [11] recorded that 58 both nests and artificial caterpillars were attacked more with in...