The Development of Integrated Pest Management in Floriculture 1994 Proposal
This proposal continues research initiated over the past few years which
has emphasized the development and implementation of integrated pest management
strategies in floriculture with a focus on biological control. The project
covers a broad range of arthropod pests attacking the major floricultural
crops in the U.S. A major objective is to formulate practical alternatives
to pesticides in floriculture and still provide for the production of a
high quality product. My 1994 proposal includes the following areas: biological
control, biological studies of pests and natural enemies, pesticide efficacy
and compatibility with natural enemies, implementation of IPM strategies
with cooperating growers, and continued compilation of literature related
to the worldwide effort in IPM related to the production of floriculture
crops. There are several reasons why the concepts of biological control/IPM
are slow to be adopted by growers: 1) lack of essential information on
which natural enemies to use and how to use them effectively, 2) incompatibility
of most natural enemies with currently used pesticides, and 3) a lack of
wide scale implementation and grower education (where this information
is available). Basic biological studies will continue on selected natural
enemies of whiteflies, aphids, and western flower thrips in an effort to
evaluate the control potential of each. In addition this will provide us
with information on how to best use these in actual release programs with
cooperating growers. Implementation of IPM/biological control studies with
cooperating potted chrysanthemum growers will continue and we will expanded
this to include cut chrysanthemum production. With all the attention concentrated
on whiteflies over the past several years, there is one pest that remains
as difficult to control as ever — the western flower thrips. My Endowment
proposal for 1994 will concentrate on biological control of the western
flower thrips using commercially available as well as novel natural enemies
we have found in California. Work will continue on developing information
on ‘biorational’ insecticides to facilitate their registration nationwide.
These products have potential for control of western flower thrips, whiteflies,
aphids, and mites and may be compatible (in some cases) with natural enemies;
hence, they may fit into an overall integrated program where biological
control and pesticides and used together to control pests. We will continue
to monitor for insecticide resistance devel- opment in spider mites, leafminers,
and whiteflies and work towards a system of coping with this serious threat
to the industry.
DETAILED EXECUTIVE SUMMARY
Biological Control
a. Evaluate the potential of a new nematode species, Thripinema aptini
discovered in a rose growers range in California, for control of the western
flower thrips. Examine the feasibility of utilizing the predatory bug,
Orius sp., the predaceous mite, Amblyseius cucumeris. and the nematodes,
Stenernema carpocapsae, for control of the western flower thrips. In addition,
we have discovered a parasitoid in California (Ceranisus sp.) which attacks
the western flower thrips and we will explore the basic biology of this
natural enemy. This is the first documented case of a hymenotperous parasitoid
successfully attacking and developing on the western flower thrips.
b. Continue the evaluation of natural enemies, on a comparative basis,
for biological control of selected pests in greenhouses. This will focus
on selected parasites, predators and pathogens of greenhouse and sweetpotato
whiteflies. This work will be through a cooperative agreement with the
USDA - APHIS laboratory in Mission, Texas.
c. Continue studies on the commercially available predator, Chrysoperla
spp. and the commercially available parasitoid, Aphidius solani, for aphid
control.
d. Continue statewide implementation of an IPM/Biological control program
for potted chrysanthemums and expand this to cut chrysanthemums.
Biological Studies
a. Continue the basic biology of thrips in an effort to understand
feeding, oviposition, and pupation behavior in selected floriculture crops.
Pesticide Efficacy and Compatibility
a. Continue the search for new pesticides which have potential for
use in floriculture. Maintain continued contact with chemical manufacturers
to assure that the ornamentals industry is not overlooked for potential
registrations. Assist in labeling materials for ornamentals and help fill
in data gaps for materials undergoing reregistration.
b. Evaluate new and old pesticides for compatibility with selected natural
enemies in culture at UC Davis. The main focus will be on leafminer and
whitefly parasites.
c. Continue monitoring for insecticide resistance in the western flower
thrips and develop alternative strategies for controlling these arthropods
and for managing the development of resistance. Examine possible resistance
to Avid by spider mites and leafminers.
Literature Review
Data and references are continually compiled which deal with arthropod
pest problems and their control in greenhouses around the world. Note:
Because of the size of my project, the number of people involved, the amount
of work proposed, and the fact that it is a multiple year project, it is
redundant to present details of the entire proposal each year. One portion
of this proposal that presents a new area of research is the implementation
of practical biological control/IPM on cut chrysanthemums. This project
also evaluates the real world use of natural enemies to control all the
major chrysanthemum pests - western flower thrips, leafminers, aphids,
and the beet armyworm. This new section is expanded more fully and takes
up most of the page limit for the 1994 proposal.
1. Introduction and Literature Review
A first attempt at using biological control on cut chrysanthemums in
California was made in the summer of 1986 in Los Angeles County; this was
a remarkable success (Jones et al. 1986). In this experiment, we released
two parasitoid species for leafminer control, however only one was recovered
consistently (Diglyphus begini - the paper lists D. intermedius which is
incorrect). For all other pests, we relied on soap, abamectin and Bacillus
thuringiensis.
This was followed by a biological control trial on marigolds (Heinz
et al. 1988) with the leafminer as the main target of control; here again,
excellent success was achieved. In this trail, whiteflies were controlled
using the parasitoid, Encarsia formosa and aphids with the predator, Chrysopa
carnea, together with spot applications of insecticidal soap. It is interesting
to note that in the 1986 and 1988 trials, 1000 and 3700 leafminer parasitoids
were released per week into a 10,000 ft2 greenhouse; in the latter trial,
control was achieved within 6 weeks of the initiation of parasitoid releases.
This research culminated in a cut chrysanthemum crop which was produced
without any pesticides in Carpinteria in 1989 (Heinz et al. 1993) — however,
this was a small experimental plot which was used primarily for validation
of the predictive leafminer biological control model (Parrella et al. 1992).
Another important facet of this trial (and all the earlier trials) was
that there were no western flower thrips to contend with, which can be
the nemesis of a complete biological control program on any crop.
A program on the implementation of IPM/biological control for potted
chrysanthemums was initiated this past year (Hesselein et al. 1993) where
we had to contend with all the major pest problems on this crop: leafminers,
aphids, western flower thrips and the beet armyworm. Results from year
one of this project were encouraging, although pest populations were not
at acceptable levels at the end of the crop in all locations of the trial.
Nonetheless, we learned a great deal from this trial which we hope to continue
and modify this in the coming year.
There is continued interest in developing the concept of biological
control in cut chrysanthemums in the state of California, and this has
been fueled by our own successes and information recently published in
England (Anon. 1993) where biological control in commercially produced
chrysanthemums has been successful. Furthermore, the concepts and ideas
that will evolve from a successful biological program on cut chrysanthemums
will have applicability to other cut flower crops.
2. Objectives and Anticipated Benefits:
1) Produce a high quality crop of cut chrysanthemums using IPM with
a firm reliance on biological control.
2) Document the utility of selected predators and parasites for control
of the major chrysanthemum pests. Initial Proposed Site
The location of the trial will be at a cooperating greenhouse in Salinas.
The grower is eager to try biological control in his chrysanthemums and
is willing to turn over approximately 2/5ths of a larger greenhouse (total
length x width = 150 ft. x 210 ft) to this effort. The actual area of the
greenhouse is 32,000 ft2 and is divided up into 5 bays. The entire greenhouse
was used for bell peppers which were recently pulled out to make way for
this chrysanthemum Mother’s Day planting. The very first bed (to the west)
was planted on Feb. 4 and the others are scheduled for the during the remainder
of February. The planting dates for the 36,000 plants in the biological
control bays are March 1st and 4th; this will be in an area of approximately
10,000 ft2. The grower plants standard chrysanthemums with cultivars such
as White and Yellow Albatross, Detroit News, and Escapade. These cultivars
will make up the bulk of the planting; Detroit News, a dark cultivar, is
probably the most sensitive to damage by leafminers and western flower
thrips. A greenhouse map will be drawn after the crop is planted noting
the location of each cultivar in each row, the number of plants, and the
location of yellow and blue sticky cards.
Yellow sticky cards were placed in the newly planted bed of chrysanthemums
as well as in the biological control beds which still had remnants of the
yet-to-be steamed pepper crop. We also placed yellow cards in the rooting
areas. The purpose of these cards is to tell us what we are dealing with
in this entire house with respect to leafminers and western flower thrips
in addition to informing the grower. Observations suggest that there are
leafminers already in the newly planted chrysanthemums as well as in the
rooting area. We suspect that western flower thrips are still coming out
of the soil in that section of the greenhouse with remnants of bell peppers.
The grower has indicated his willingness to screen the biological control
section of the greenhouse from the other chrysanthemum crop in addition
to providing some screening of outside vents. The type of screening employed
is not yet known.
Current State of Crop Production at Cooperating Greenhouse Operation
The level of both leafminers, aphids and western flower thrips currently
in the crops being harvested in adjacent greenhouses were considerable.
Only qualitative assessments were made, but the level of this ‘acceptable’
injury was very encouraging and directly addresses the concept that we
do not have to achieve unrealistic levels of pest populations in the crop
for biological control to be deemed successful. It is hoped that we can
maintain levels of leafminers, aphids, and thrips below what the grower
is currently able to achieve with insecticides. Biological control of leafminers
and aphids should be possible given commercially available natural enemies
(and Diglyphus from UC Davis). However, western flower thrips pose the
greatest challenge. Western flower thrips were abundant in the greenhouses
and there was evidence of tomato spotted wilt virus (Impatiens Necrotic
Spot Virus) in many of the plants. This will probably become more of a
problem as temperatures increase.
3. Materials and Methods
The entire biological control planting area, separated from the remaining
production with screening, will be one replicate. This trial will be repeated
three times with successive crops, thus there will be a total of three
replicates of the biological control trial. Establishing controls are always
a problem with this type of trial and we will follow a similar protocol
using exclusion cages developed by Heinz & Parrella (1990). However,
in all the earlier trials, one of the major goals was to document the impact
of parasitoid releases on the leafminer population — other pests were
considerably less important. In the current trial leafminer control is
critical given the high levels of leafminers present in adjacent crops.
However, documenting the control of other pests is even more important.
The focus is on aphids and western flower thrips, because we have ample
evidence to suggest that Diglyphus works for biological control of leafminers,
but little documented evidence that natural enemies can be effective against
these other pests. Thus the use of control cages must document the impact
of natural enemy releases against multiple pests.
Yellow and blue sticky cards will be placed 5 - 10 cm over the crop
and at the rate of one per 400 ft2 and these will be counted and changed
weekly. I prefer that the entire card be counted, but when (and if) higher
populations begin to appear of the cards, the system of counting only 20%
of the card can be employed (Heinz et al. 1992). I haven’t decided if we
will have cards in the cages; if so, they will be proportional to the one
card per 400 ft2 that are used in the greenhouse proper. Counts will include
leafminers, aphids and western flower thrips in addition to any parasitoids
that may be released. In an adjacent greenhouse with the crop planted at
approximately the same time, we will establish sticky cards at one per
1000 ft2 in an alternating yellow and blue pattern and these will also
be counted weekly. This will serve as background information on resident
natural enemy populations that may be migrating into the biological control
greenhouse. See Heinz & Parrella (1990) for an explanation of how this
information is used in the final analysis of parasitoid impact.
Control cages must be put over the same cultivar — I envision six such
cages placed over the crop. These will not be in randomly assigned positions
in the greenhouse because there must be the pest in question present in
the cages. Cages will be put into position soon after the pest is detected
and just before the first natural enemies are released for that particular
pest. For leafminers, this will be within seven days of planting; aphids
and western flower thrips may move in later in the crop. This is where
the potential problem comes in — these insects may not appear at the same
time in the greenhouse so cages will have to be staggered over time to
coincide with the appearance of pests. In addition, there may be overlap
in the cages (i.e., both leafminers and aphids may be in one of the cages).
Assuming only one pest per cage there will be one cage where no natural
enemies will be released and another where releases will be prorated down
based on the proportion of the cage area (or number of plants in the cage)
compared to the entire greenhouse. The control cages without natural enemies
will represent the development of pest populations in the absence of natural
control and population development of the pest will be contrasted in cages
with and without parasitoids. Data will be taken from the entire greenhouse
and all will be presented, but the cage data will be compared statistically
to demonstrate the impact of the natural enemy. Data from the greenhouse
proper will demonstrate the successful use of biological control to the
grower.
Sampling and Biological Control
The presence absence sampling plan for leafminers based on a fixed
sample size of 100 leaves from the middle section of the chrysanthemum
plant will be used to estimate leafminer densities. Leaves must be taken
at random from the entire biological control planting; there is no effect
of cultivar on the sampling program. One leaf per plant will be examined
for each of the cages in the greenhouse. Sampling for western flower thrips
and aphids will be done by examining the terminal growth points (top five
leaves); there will be ten examined from each cultivar per week. This will
not be destructive sampling — the sampler will look all over and in the
terminal growth for the presence of thrips, aphids and any natural enemies.
Any incidence of Impatiens Necrotic Ringspot Virus will be recorded per
cultivar. Worms will not be quantified; the presence of any worms or worm
feeding will automatically signal the application of Bacillus thuringiensis.
Natural Enemy Release Rates
All the cultivars will be ranked as to their relative susceptibility
to the various pests attacking chrysanthemum, heavier releases natural
enemy will be made on the most susceptible cultivars. The parasitoid Diglyphus
begini will be released at the rate predicted by model. For the intent
of placing an order — 500 per week is not unrealistic. Hopefully we can
supply an additional 500 per week from our UCD colony if they are needed.
Aphidius sp. will also be used at rates recommended by the producing insectary.
For control of aphids, we will rely on the use of Chrysoperla spp. released
at the rate of 5 - 20 per plant; higher densities will be applied to sensitive
cultivars. For thrips, we will make use of Orius at the recommended of
one per five ft2. In addition, we will release Amblyseius cucumeris at
the rate of 20 - 50 per plant. All releases will be weekly; this may be
changed as the trial progresses when the need for such excessive numbers
of natural enemies may not be as great as anticipated.
Data Collection
Sampling must the done at the same time each week and natural enemies
must be released at the same time each week. This should be early morning
for both. A major concern is the control cages — we do not want any natural
enemy movement into these. Sampling in early morning when insect activity
is low is the only way to prevent this especially with the labor intensive
terminal sampling that must be done. Data collection sheets will be prepared
and standardized. Because of the intense nature of the sampling effort,
it may be best to change and count sticky cards and release natural enemies
on Monday in addition to other routine measures: 1) take plant height and
count the number of leaves from one plant of each cultivar, and 2) take
light intensity readings in the greenhouse and in the cages. The leaf and
terminal sampling will be done on Thursday; this is labor intensive and
must be completely as quickly as possible.
4. Literature Cited
Anonymous. 1993. Orius - a star performer. Grower. Jan. 7, 1993. pp.
29 - 30.
Hesselein, C., K. Robb, Julie Newman, Richard Evans, & Michael Parrella.
1993. Demonstration/Integrated Pest Management for potted Chrysanthemums
in California. Proceedings IOBC Conference, Asilomar, Calif. 16(2): 71-76.
Heinz, K. M., Julie Newman, & Michael P. Parrella. 1998. Biological
control of leafminers on greenhouses marigolds. Calif. Agric. 42: 10 -
12.
Heinz, K. M. & Michael P. Parrella. 1990. Biological control of
insect pests on greenhouse marigolds. Environ. Entomol. Forum Section 19:
825 - 835.
Heinz, K. M., Michael. P. Parrella, & Julie P. Newman. 1992. Time-efficient
use of yellow sticky traps in monitoring insect populations. J. Econ. Entomol.
85: 2263 - 2269
Heinz, K. M., L. Nunney, & M. P. Parrella. 1993. Toward predictable
biological control of Liriomyza trifolii infesting greenhouse cut chrysanthemums.
Environ. Entomol. Forum Section (submitted) Jones, V. P., Michael P. Parrella,
Don R.
Hodel. 1986. Biological control of leafminers in greenhouse chrysanthemums.
Calif. Agric. 40: 10 -12.
Parrella, M. P., K. M. Heinz, and L. Nunney. 1992. Biological control
through augmentative releases of natural enemies: a strategy whose time
has come. Am. Entomol. 38: 172 - 179.
5. Budget
2 full time Laboratory Assistant II @ $4,890/month x 12 $ 58,560 (includes
benefits)
Miscellaneous Supplies $ 1,000
Total Request $ 59,560
Note: This funding is requested for individuals already in these positions
based on funding from previous years. They are well-trained workers who
perform the detailed work outlined in this project very well.
6. LEADER QUALIFICATIONS
Dr. Parrella’s responsibilities at Davis are 90% research and 10% teaching
in addition to being Chairman of the Department. He teaches Economic Entomology
(Entomology 110) and contributes to other courses in the Departments of
Entomology and Environmental Horticulture and in the Plant Sciences. His
research program concentrates in the area of ornamentals with a focus on
developing pest management systems with a firm reliance of biological control.
Dr. Parrella has worked with many different ornamental crops and with most
of the major pests attacking these crops. His research involves determination
of basic insect biology, developing monitoring systems, evaluation of old
and new insecticides for phytotoxicity and efficacy, evaluation of new
insecticide application techniques, and understanding and managing insecticide
resistance. The main emphasis of his research focuses on the biology/ecology
of predators and parasites and their potential use for biological control
in greenhouses.
An important aspect of Dr. Parrella’s research and teaching is directing
graduate students and postgraduate scientists — he currently has 6 (3
Ph.Ds., 2 Masters, and 1 postdoctoral researcher) working on different
pest problems affecting the ornamental’s industry.
Dr. Parrella publishes regularly in scientific and trade journals and
is the author of more than 200 publications. For four years he wrote a
monthly column on ‘Pest Management’ for the trade magazine, Greenhouse
Manager and he currently writes a monthly column entitled ‘IPM with Parrella’
for the trade magazine GrowerTalks. Dr. Parrella continues to emphasize
oral presentations as a method of disseminating information at the state
and national levels; he averaged more than 25 presentations per year from
July 1, 1990 - June 30, 1993. He organized the ‘First Conference on Insect
and Mite Management’ on Ornamentals held in San Jose, Calif. in 1985 which
has become an annual event sponsored by the Society of American Florists.
He was co-organizer of the 4th and 6th such conferences which were held
in Phoenix in 1988 and San Jose in 1990, respectively. He was principal
organizer for the first joint meeting of the Western Palearctic and Nearctic
working groups for Biological/Integrated control in greenhouses (a subgroup
within the International Organization of Biological Control). This was
held in California in April, 1993. He is co-organizer of the International
Conference on Thysanoptera to be held in Burlington, Vt. in late September.
Dr. Parrella has acted as a consultant for the following organizations:
Society of American Florists (SAF) and the USDA/APHIS on leafminers; for
the Professional Plant Growers Association on the relaxation of Quarantine
37; for the California Association of Nurserymen on quarantines regarding
the brown garden snail; for Roses Inc. and the Society of American Florists
on the new proposed amendments to FIFRA; and he serves on the agricultural
advisory committee for Merck, Sharp and Dohme. Dr. Parrella is currently
a member of SAF’s National Floriculture Research Initiative Task Force.
In 1986, Dr. Parrella received the Researcher of the Year Award from
the California Association of Nurserymen. In 1987, Dr. Parrella received
the Entomological Society of America (ESA) Recognition Award in Entomology
sponsored by the Ciba-Geigy Corporation. This award, presented annually
by the ESA, a professional society with more than 9,200 members, is intended
‘to provide additional recognition to entomologists who have made or are
making significant contributions to agriculture”. In 1991, Dr. Parrella
received the Futura Award from the Professional Plant Growers Association
in recognition of contributions made to the floriculture industry by building
for the future through teaching and research.
