Recipient Organization
ORBITAL TECHNOLOGIES CORPORATION
1212 FOURIER DRIVE
MADISON,WI 53717
Performing Department
(N/A)
Non Technical Summary
Plant-eating insect pests cause significant economic loss in commercial greenhouse growing operations, sometimes amounting to tens of thousands of dollars per hectare. Insects as a vector of plant pathogens also rank very high on the problem list for greenhouse/hothouse growers. Integrated Pest Management is a pest control strategy that "uses an array of complementary methods: mechanical devices, physical devices, genetic, biological, legal, cultural management, and chemical management" to help or prevent these economic losses while significantly reducing the use of pesticides. Although host utilization by insects is broadly dictated by factors such as host species, season, plant nutrition, and water status, many insects that are significant economic pests in greenhouses, including thrips, aphids, and whiteflies use vision as a primary cue to orient to their hosts. Vision cues are predominantly related to color, or more specifically hue, color saturation, and brightness. Most insects studied have green, UV, and blue receptors, though red receptors have been found in some. Color can be used in two ways to protect crop plants, either as a mechanism to attract insects to traps or "decoy" plants, or to repel insects by interrupting the sequence that begins with their orientation to the plant from a distance and ends with establishment on the plant. A new revolution in horticultural lighting is underway with the development of solid-state lighting systems, the first lighting system that allows control of a lamp's spectral output. During research with plants in controlled environment rooms outfitted with red/blue light emitting diode (LED) arrays it was apparent that plant appearance was radically different than when observed under broad spectrum light sources. This led to the hypothesis that modifying lighting to change the appearance of plants might disrupt the ability of pest insects to locate and attack host plants, or inversely, that the appearance of decoy crops and physical traps could be enhanced to increase their effectiveness. This would allow the use of supplemental lighting systems that might already be in greenhouses to be used as a new tool in a grower's IPM program. The objectives of the proposed project is to identify solid-state lighting protocols that: (1) reduce predation of protected agriculture crops; (2) increase attraction to decoy crops; (3) enhance the attraction to physical traps (i.e., sticky cards); or (4) any combination of the above, while not disrupting beneficial insects or plant growth. If LED systems can be configured to help reduce insect damage and insect-related vectored diseases in greenhouses, these systems will gain additional usefulness by becoming an important component of the grower's IPM program, and could help to reduce the annual per hectare costs of greenhouse pest control.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Goals / Objectives
It has been established that many insects use vision as a primary cue to locate hosts, and vision cues are predominantly related to color. Solid-state lighting systems (LEDs) are the first lighting technology that allows practical control of the actual lamp spectrum. During research with plants in controlled environment rooms outfitted with red/blue light emitting diode arrays it was apparent that plant appearance was radically different than that observed under broad spectrum light sources. This led to the hypothesis that modifying light, which changes the appearance of plants, might disrupt the ability of pest insects to effectively locate and attack host plants, or inversely, enhance the effectiveness of trap plants. The objectives of the proposed project are to identify solid-state lighting protocols that reduce herbivory of high value greenhouse crops while not disrupting beneficial insects or nominal plant growth. The primary technical questions to be addressed by the proposed project include: (1)What light wavebands or combination of wavebands will attract pest insects to physical (sticky traps) or biological targets (decoy plants) (2)What light wavebands or combination of wavebands will cause pests to avoid or fail to establish on potential host plants (3)Can effective lighting hardware systems and operational protocols for insect control be integrated into a greenhouse lighting system used to supplement solar irradiance while supporting good plant development The expected output of this work is a set of spectral composition patterns that can disrupt pest infestations of crop plants. These patterns would be used to develop specifications for LED based greenhouse lighting systems that can function as part of an integrated pest management program in a manner that has the cost, efficacy, and other performance parameters necessary for success in the agriculture lighting market.
Project Methods
The Phase I project will focus on using LED lighting systems to test the response of spectral composition on the interaction between pest insects and physical targets, and the response of spectral composition on some simple pest insect/host plant systems. The response of aphids and thrips to colored targets under broad spectrum light and under several narrow wavebands generated by a LED lighting system will be tested using standard free-choice tests. For each test insect species, the colored target (defined by chromaticity coordinates and spectrum) will be ranked by the number of insects attracted to that target over the specified test interval. Targets that appear to not attract insects will be tested in no-choice tests to determine if the lower ranked color combinations actually disrupt insect attraction to the target or are just less preferable over other color combinations. Insect behavior will be monitored for each test to see if there is avoidance of the color zone, congregation at the color zone, or just random movement around the arena. Targets that appear to attract insects will be tested to determine the impact of altered light properties, such as intensity, on this response. The control flexibility of solid-state lighting allows manipulation of light in ways other than changing spectral composition. These tests will provide a preliminary indication of whether light can be manipulated to disrupt a demonstrated attraction of a test insect to a physical target. To determine if the response to colored targets carries through to actual plants, and to identify potential light protocols that may be effective for either attracting or repelling pests, a series of free choice tests will be conducted using three different target insect and host plant combinations. A multispectral LED lighting system will be used to provide narrow bandwidth light treatments to identify lighting protocols that enhance insect pest attraction to trap plants or that acts to interfere with visual cues and host plant location. These results will be used to develop a conceptual design for an advanced lighting system in Phase II.