Socio-ecological analysis of prickly pear agroecosystems and its relationship with wild cochineal dynamics

Ecosystem services of natural pest regulation can contribute to pest control in sustainable agroecosystems. For the control of the wild cochineal (Dactylopius opuntiae Cockerell) (Hemiptera: Dactylopiidae), regulation by natural enemies has been studied. However, this type of regulation has not been evaluated from the point of view of socio-ecological analysis with the management practices by farmers. In this research we analyzed the organic and conventional management systems of prickly pear (Opuntia ficus-indica Mill) in relation to population regulation by natural enemies, and the management practices that allow the control of cochineal. Management systems were characterized throughout the production process through interviews to farmers and participant observation. To determine population regulation, random sampling of cochineal infestation levels by management system and by type of cladode that allows protection of cochineal was carried out. The density of natural enemies per infestation level was also obtained. To identify signs of regulation, we obtained histograms of the frequency distribution of the infestation level and determined if distribution is adjusted to a power function. The decision of formation pruning was the cultural practice that growers relate to pest control. This is evidenced by the lower density of cladodes that allow protection from cochineal because they allow high levels of infestation. The frequency distribution of the infestation frequencies had a high level of adjustment to a power function, suggesting the presence of population regulation processes in the organic management system. Different densities of natural enemy species were found according to management type. The contrasts between management indicate that farmers taking advantage of natural regulation by natural enemies, performing adequate pruning and maintaining organic management can increase the probability of cochineal extinction in cladodes.