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United States Department of Agriculture

Agricultural Research Service

Title: Alternative landscape design and management and insect diversity in residential landscapes

item Lorenzo, Alfredo
item Legaspi, Jesusa - Susie
item Pescador, Manuel
item Muchovej, James
item Duke, Edwin

Submitted to: Proceedings of Florida State Horticultural Society
Publication Type: Proceedings
Publication Acceptance Date: 9/15/2003
Publication Date: 10/1/2003
Citation: Lorenzo, A., Legaspi, J.C., Pescador, M., Muchovej, J.J., Duke, E.R. Alternative landscape design and management and insect diversity in residential landscapes. Proceedings of Florida State Horticultural Society.

Interpretive Summary: In residential landscapes, the numbers and types of plants present affect pest insects and their natural enemies. Landscape designers need to be aware of how the plants they select for use can affect the numbers of pest insects that will attack the plants, and how these pests will in turn affect the numbers of beneficial predatory insects that will feed on them. A study conducted by USDA, ARS scientists at the Center for Medical, Agricultural and Veterinary Entomology on 11 residential homes in Florida measured some of these relationships. Increasing the types of plants in a site resulted in more pests and more predators. However, adding still more new types of plants to a landscape eventually caused more pests to appear than predators. To a lesser degree, adding more plants of the same species also caused pest numbers to increase. Based on this study, landscape designers must be aware that plant diversity may influence urban pest problems.

Technical Abstract: An analysis of data collected from several residential landscapes in Tallahassee, Florida, revealed positive and negative relationships between the number of predator insects and pests in the landscape and the richness and evenness of plant species at the site, respectively. While the number of predator insects in a landscape increased little relative to increasing numbers, the number of insect pests decreased at a significantly greater rate. Two explanations for these results are likely. First, relatively few plants harbored pests throughout the period of the study. Therefore, adding plants of the same species had little effect on altering the number of predator insects and pest in a landscape. Secondly, pests tend to be relatively specialized in their key host range. When different species of plants are added to a landscape, more opportunities are created for specialized insects to colonize the site and increase the richness and abundance of the insect population. When used in conjunction with previous investigations involving landscaping, these results provide landscape designers and managers information to make decisions on plant usage more efficiently and effectively.

Last Modified: 10/16/2017
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