- Vegetables: greens (leafy)
- Pest Management: integrated pest management
Habitat management strategies that increase the functional agrobiodiversity of agroecosystems have been associated with reductions in the number of many herbivore pests, in temperate, subtropical and tropical cropping systems. Increasing the functional diversity of agroecosystems by combining crops with non-crop, secondary plant functional groups that provide resources for natural enemies and/or alter the behavior and distribution of pests has been a particularly effective approach to pest management. A common form of functional diversification strategy used in IPM is the push-pull approach, or the spatial integration of secondary plant species with pest attractant and repellent stimuli within agroecosystems. Typically, repellent plants (the “push” component) are placed within close physical proximity of a field (the “pull” component). The net movement of pest species is therefore away from the susceptible crop area and into a nearby stand of attractant plants. While push-pull approaches are pest-specific, they can also be developed to lure beneficial insects towards the source of concentrated pest populations to maintain low pest numbers and reduce pest spillover into the crop. The incorporation of natural enemy and pest attractant plants within fields and along field margins has been shown to substantially increase parasitism and mortality levels in multiple species of aphids.
In this project, we explored the utility and effectiveness of a push-pull technology to manage pests in South Texas. While push-pull pest management is by no means a new approach, very little is known on the role of deploying repellent and attractant plants in tandem in order to reduce pest populations in agricultural fields in subtropical Texas. Our research revealed the utility of such approaches. For example, in a study of different "push" crops, we found that the presence of flowering non-crop plants such as buckwheat were associated with lower presence of aphids. We also found that beneficial insects such as convergent lady beetle larvae were more abundant on brassica crop plants surrounded by flowering dill and Indian mustard. These trends reveal the potential of these agroecological techniques to reduce pest pressures in vegetable crops in south Texas.