Source: UNIV OF MARYLAND submitted to
FLOWERING PLANTS TO ENHANCE BIOLOGICAL CONTROL OF INSECT PESTS IN NURSERIES
 
PROJECT DIRECTOR: Shrewsbury, P. M. Patt, J. M.
 
PERFORMING ORGANIZATION
ENTOMOLOGY
UNIV OF MARYLAND
COLLEGE PARK,MD 20742
 
NON TECHNICAL SUMMARY: The green industries is one of the most rapidly growing and economically important components of agriculture in the United States. Chemical pesticides are the primary pest control method used by the green industries. The purpose of this project is to develop an alternative control strategy for insect pests of woody ornamentals that is based on enhancing the ornamental nursery system to favor beneficial insects. This ecological approach will result in fewer insect outbreaks and a reduction in the use of pesticides in ornamental nursery systems, thus creating more sustainable nurseries.
 
OBJECTIVES: Our long term research goal is to develop an alternative control strategy for insect pests of woody ornamentals that is based on enhancing the ornamental nursery system to favor beneficial insects. This ecological approach will result in fewer insect outbreaks and a reduction in the use of pesticides in ornamental nursery systems, thus creating more sustainable nurseries. This research will further our understanding of the role that habitat complexity, specifically the incorporation of flowering plants, plays in herbivore - natural enemy population dynamics. The specific objectives of our studies are as follows: 1) to evaluate the effect of incorporating flowering plants into production nurseries on herbivore populations; 2) to evaluate the effect of incorporating flowering plants into production nurseries on the overall community of arthropod fauna; and 3) to determine if increases in the abundance of natural enemies in cropping systems containing floral resources is a function of the presence of those floral resources.
 
APPROACH: This experiment will examine how incorporating flowering plants into a production nursery will influence the population dynamics of herbivorous insects through the effect of flowering plants on the taxonomic diversity, abundance, movement, and foraging behavior of natural enemies. Experimental field plots will be constructed to simulate field plots in a commercial nursery. Strips of flowering plants will be interplanted within the plot of production plants. Production plants will be infested with herbivore pests and herbivore survival, and the taxonomic diversity and temporal and spatial abundance of natural enemies will be determined through intensive, periodic sampling over a 3 year period. Utilization of floral resources by natural enemies will also be quantified in our study system.
 
CRIS NUMBER: 0186021 SUBFILE: CRIS
PROJECT NUMBER: MD-ENTO-7170 SPONSOR AGENCY: CSREES
PROJECT TYPE: NRI COMPETITIVE GRANT PROJECT STATUS: TERMINATED MULTI-STATE PROJECT NUMBER: (N/A)
START DATE: Oct 1, 2000 TERMINATION DATE: Sep 30, 2003

GRANT PROGRAM: BIOLOGICALLY BASED PEST MANAGEMENT
GRANT PROGRAM AREA: Plant Systems

CLASSIFICATION
Knowledge Area (KA)Subject (S)Science (F)Objective (G)Percent
215211010704.250%
215211011304.230%
216211010704.210%
216211011304.210%

CLASSIFICATION HEADINGS
KA215 - Biological Control of Pests Affecting Plants
KA216 - Integrated Pest Management Systems
S2110 - Ornamental trees and shrubs
F1130 - Entomology and acarology
F1070 - Ecology
G4.2 - Reduce Number and Severity of Pest and Disease Outbreaks


RESEARCH EFFORT CATEGORIES
BASIC (N/A)%
APPLIED 100%
DEVELOPMENTAL (N/A)%

KEYWORDS: biological control (insects); insect control; flowers; nurseries; ornamental plants; habitat management; conservation; natural enemies; azalea; tingidae; integrated pest management; structural analysis; management alternatives; woody ornamentals; beneficial insects; insect ecology; sustainable agriculture; communities (ecology); cropping systems; performance evaluation; production systems; herbivores

PROGRESS: Oct 1, 2000 TO Sep 30, 2003
Four flowering plant species were examined to determine which species would be appropriate beneficial insectary plants in a conservation biological control approach. Flower species included: 1) Sweet Alyssum; 2) Coriander; 3) Dill; and 4) Buckwheat. Preliminary analysis of samples for natural enemy and alternative prey abundance found that all plants attracted natural enemies and alternative prey. Using a combination of flower species in a conservation biological control approach is likely the best strategy. Additional data from 2002 and 2003 are presently being analyzed to determine differences in arthropod species richness and diversity between flower species, and to determine potential key natural enemies impacting herbivores. In 2002, field studies were conducted to evaluate the impact of natural enemies on herbivore populations at varying distances from floral resources. The four flowering plant species were planted in field research plots. Plant / herbivore systems (Oleander aphid, Aphis nerii, on Asclepius; Hawthorn lace bug, Corythuca cydoniae, on Cotoneaster) were placed at four distances (0, 2, 10, and 20 meters) from the flowering plant beds and from a control bed with no flowers. In general, herbivore densities were lower on plants placed within and 2 meters from the flowerbeds compared to plants at the same distance from the no flowerbeds. At further distances, floral resources had little or no effect on herbivore populations. In 2002 and 2003, field studies were conducted to examine the influence of 3 levels of habitat complexity on natural enemy activity and to determine at what distance natural enemies from the complexity treatments impacted herbivore populations. Complexity treatments included beds of flowering plants (high complexity), turf grass (moderate complexity), or weed cloth (low complexity). Bordering the edge of each treatment were strips of black weed cloth. The two plant / herbivore systems were placed at increasing distances (0 and 3 m) from the edge of the treatment beds (i.e., distance 0 plants were just inside the treatment bed, distance 3 m were set out on the weed cloth). Overall, simple habitats (weed cloth) favored aphid and lace bug outbreaks. Whereas, adding turf or flowers, suppressed aphid and lace bug populations. These results suggest similar predation pressure exists in flower beds and turfgrass. Preliminary analysis of the effect of distance and complexity, indicate lower herbivore abundance closer to the flowers and turf suggesting natural enemies do not move far from the flowering plants or turf. Natural enemy data collected from sampling the treatment beds and study plants are presently being analyzed. Implications of these results to production nurseries are to grow plants in beds with turf or other flowering vegetation surrounding the beds. This should result in increased predator and lower pest abundance. Information from these studies has been extended to professionals and end users. Results have been presented at: 6 professional meetings; 3 University colloquiums (Entomology departments); and 15 extension / outreach training conferences and short courses.

IMPACT: 2000-10-01 TO 2003-09-30 Specific information on the influence of varying levels of habitat complexity on natural enemy taxa and abundance; the dispersal of natural enemies; and the range at which they impact herbivores in ornamental systems will allow us to more effectively design ornamental plant systems (nurseries and landscapes) that conserve natural enemies and reduce pest populations. Refining and improving the efficacy of the conservation biological control approach should lead to greater adoption by plant managers and producers of this alternative pest management approach. This should result in greater reduction in pesticide inputs and lead to the development of more sustainable agro-ecosystems. These studies should have similar implications to other agricultural systems.

PUBLICATION INFORMATION: 2000-10-01 TO 2003-09-30
No publications reported this period

PROJECT CONTACT INFORMATION
NAME: Shrewsbury, P. M.
PHONE: 301-405-7664
FAX: 301-314-9290