Research in the Parrella Laboratory
Overview
My research program develops IPM strategies that have a basis in reality for the Environmental Horticulture industry. This includes floriculture crops, nursery and bedding plants, and landscape plants in the urban environment. The laboratory works with many important pests including western flower thrips, silverleaf and greenhouse whiteflies, Liriomyza leafminers, green peach and melon aphids, mealybugs, and spider mites. Natural enemies of these pests also take center stage as we are working with the parasites and predators of all these pests. There are unique aspects associated with developing IPM programs for aesthetic value crops and these must be taken into consideration if programs are eventually adopted by the industry. My laboratory focuses on understanding the relationship of the pest to the crop (including its unique production practices), to the environment and to its natural enemies. Simply stated, investigating the basic biology and ecology of a pest at the individual and population level is the core of my program. The following research is underway in my laboratory: (as of June, 2004):
Development of IPM Programs for Thrips and Tospoviruses
We are in the final phase of this project which has been supported by the American Floral Endowment. This is a multi-state effort and includes: Michael Brownbridge and Margaret Skinner (in the Bruce Parker laboratory) at the Univ. of Vermont; Kevin Heinz at Texas A&M, Arnold Hara (Univ. of Hawaii) together with Beth Mitcham (UC Davis); and Diane Ullman at UC Davis. A recent addition to this group has been Dr. Raymond Cloyd at the Univ. of Illinois. Each contributes his or her expertise to the program - Dr. Brownbridge focuses on fungi for thrips control and application methodology, Dr. Heinz concentrates on biological control, Dr. Hara and Dr. Mitcham conduct research on postharvest control of thrips in cut. Dr. Ullman works with monitoring, diagnostics, and management of tospovirus and Dr. Cloyd focuses on managing thrips in bedding plants, including evaluation of host plant resistance. My program focuses on developing sampling plans, taxonomic keys, reduced risk pesticides, and biological control. We are in the final year of a 4-year project.
Development and Implementation of IPM in Gerbera
Gerbera is one of the largest cut flower crops in the United States and the acreage devoted to this crop continues to increase. While the focus of this project is cut Gerbera, there is a direct overlap to gerbera grown as a potted crop. California is the largest producer with more than 60 million stems harvested annually at a value in excess of $30 million. A Gerbera Pest Management Alliance was formed with the California Cut Flower Commission, the California Department of Pesticide Regulation, University of California researchers/specialists, county advisors and allied industries (including Syngenta BCM & Plant Sciences, Inc.) and various manufacturers of reduced risk pesticides. The objective of the alliance is to develop an IPM program for gerbera growers in California that relies on monitoring, economic thresholds and the integration of biological control with reduced risk pesticides. The focus of this program are the major pests including western flower thrips, greenhouse and iris whiteflies, two-spotted spider mites, leaf-miners, and powdery mildew. In addition, we address minor pests as they arise including the citrus mealybug and sweet-potato whitefly. There are four cooperating growers in this project working through the farm advisors (Dr. Karen Robb in San Diego Co., Julie Newman in Santa Barbara and Ventura Cos., and Steve Tjosvold in Santa Cruz and Montery Cos.) in the major gerbera growing areas of California. Although the Gerbera Alliance was initially proposed in 2002, it has been delayed for a variety of reasons (most of which relate to funding). This is actually the first year of the project with funding from the California Cut Flower Commission, UC IPM program, the Hansen Trust, and the USDA (via the National Floriculture & Nursery Research Initiative).
Reduced Risk Pesticides
Routine screening work is done to evaluate new and promising reduced risk pesticides for potential inclusion in IPM programs. Whenever possible these are evaluated for compatibility with natural enemies of the selected pests. In the greenhouse/headhouse areas controlled by my laboratory, we maintain colonies of two-spotted spider mites, western flower thrips, citrus mealybugs, melon aphids, greenhouse and sweet-potato whiteflies, and Liriomyza leafminers. We receive generous donations (on a weekly or biweekly basis) of plant material from Koppert Biological Systems, Terra Nigra, Yoder Brothers, GroLink Inc., Paul Ecke Poinsettias, Goldsmith Seeds, and Nurserymen's Exchange. In addition, Nurseymen's Exchange, Everbloom and Westland Floral provide my program with much needed supplies and plant material on an as-needed basis.
Students and Postdoctoral Scientists in the Laboratory
Cheryle O'Donnell (BS, MS University of California, Davis)
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Cheryle recently completed her MS degree in my lab entitled 'The Biology and Identification Biology of Selected North American Thysanoptera Associated with Ornamental Plants'. Her Ph.D. will concentrate on developing molecular techniques for rapid identification of thrips of quarantine importance and the use of morphological and molecular techniques to highlight the phylogenetic relationships of the genera Thrips and Frankliniella within the Tubilifera. Support for Cheryle's project comes from internal support with Entomology at UC Davis and from the USDA Floriculture and Nursery Research Initiative.
Roy Kaspi (Ph.D., The Hebrew University of Jerusalem, Israel)
Roy is looking at the potential of releasing sterilized Liriomyza leafminer males into a greenhouse to bring about reduction in leafminer populations. He will be examining this technique in conjunction with releases of the parasitoid Diglyphus. Work has been completed on the viability of this technique and he has demonstrated that it can work synergistically with Diglyphus. We are about to initiate large greenhouse trials on the Davis campus and then plan trials with a commercial grower (hopefully as part of the Gerbera Alliance). Roy was initially supported by a BARD Postdoctoral fellowship and now works under a USDA NRI grant. Chrysanthemum cuttings donated by Yoder Brothers are essential to this project.
Andrew Sutherland (BS Environmental Horticulture, Univ. of Florida)
Andrew comes to my project as a graduate student in the Horticulture and Agronomy Graduate Group. He will be working on a little-known coccinellid in the genus Psyllobora which is an obligate feeder of powdery mildew. In addition, Andrew has initiated some work where he is examining the utility of releasing mixtures of Encarsia and Eretmocerus for whitefly control. This is a common practice for whitefly control in Gerbera. Andrew's project is supported by the Slosson Endowment Fund.
Vanessa Carne-Cavagnaro (Ph.D. Ecology, University of Adelaide, Australia)
Vanessa is taking the lead and directing the Gerbera Pest Management Alliance. This involves training the scouts hired by each of the county advisors, laying out the sampling designs at each location, collating and analyzing the data, getting this information back to the scout and advisor in a timely manner, and dealing with day to day issues surround the alliance when they arise. Vanessa will be developing a web site for this project as well as newsletter that will go out to all gerberas producers in the state 6x per year.
Personnel
Tom Costamagna; Senior Superintendent of Agriculture
(BS in Environment Horticulture and Landscape Architecture, UC Davis)
Robert Starnes; Principal Agricultural Technician
(BS in Botany, Humboldt State)
Trinity Strehl (Post Graduate Researcher)
(BS Chemistry, UC Davis)
Tom, Bob and Trinity manage all aspects of greenhouse and laboratory operations. We have state-of-the-art greenhouses where plants produced for research rival those grown in commercial production. These individuals assist the postdoctoral scientists and students with their projects, while conducting numerous research projects (for example, the evaluation of reduced risk materials) on their own.
Facilities
My lab group is housed in Room 304 (Briggs Hall) which is over 1000 sq. ft., and includes a fume hood, and three small internal offices. There is desk and bench space to house all and to process field samples, conduct bioassays, etc. We rear a number of insects in this lab as well. The lab contains numerous Mac computers and we regularly upgrade or buy new computers. We have the necessary equipment to take and edit digital photographs and videos of insects and to burn these onto a CD or DVD. Other equipment in the laboratory includes microscopes (some with camera attachments), a leaf area meter, environmental chambers, electronic data temperature probes, and a LICOR LI6400 photosynthesis system. We maintain five separate 400 sq. ft. greenhouses in the Orchard Park area (near to Entomology) on campus. Adjacent to these greenhouses is a head-house area consisting of two small rooms where plant material is potted and processed. In addition, many of the insect colonies are maintained in cages at this location. We have a larger 3000 sq. ft. greenhouse on the west side of campus where the bulk of our plant material is grown. Refitting this greenhouse is an ongoing process and we recently added a new concrete floor, covering, swamp coolers, environmental controls, automatic irrigation and fertilization, and a high pressure misting system. Water cooled lights are soon to be added. Hydroponic gerbera production is located in this greenhouse. We also have a double-wide trailer at this site which is used for additional lab space and for insect rearing. There is large, metal framed quonset hut adjacent to the trailer and we have retrofitted this for rearing leafminers in support of the sterile insect release project. The laboratory maintains flat-bed truck (full-time) from the motor pool for field work and for daily work on campus.
To Prospective Students
Students coming into the laboratory need to be secure individuals who are motivated and self-starters. All students are supported financially either by my own grants or by the department. In addition, there is usually financial support for the students project. However, my hope is that students will contribute to the financial security of the lab and their own project by writing grants to support their projects. There are always many sources of funding within the Environmental Horticulture industry, among others.
I expect students to interact with growers and to have a strong field component of their research. I cannot stress the 'outreach' part of this program enough. I expect students to be adept at giving both research and grower-oriented presentations when they are finished. I have no reservations about students attending scientific meetings. As long as you are presenting a paper, I usually grant permission and provide financial support to attend.
One thing that incoming students have to understand is that as the Associate Dean for the Division of Agricultural Sciences on the Davis campus, more than 80% of my time is spent on college/campus matters and these come first. In addition, most of my time is spent in Mrak Hall, which is on the other side of the campus from Entomology. Therefore, I am not that accessible as a Major Professor. This does not mean that I do not care about your project or that we will not meet on a regular basis-in fact I will meet with you as often as you would like. I try to come and spend Thursdays in the laboratory - I am definitely not there the rest of the week. To offset this, others in the lab can act as resources for you and you should feel free to contact them to get more information.
If what I have said here intimidates you or you feel that this project is a bit too overwhelming to 'jump' into, please do not apply. On the other hand if you find that becoming part of a very dynamic program in a very strong department on a great campus in the heart of the environmental horticulture industry in the US is exhilarating, I look forward to talking with you.
