U.S. patent application number 09/156011 was filed with the patent office on 2001-07-05 for novel methods and materials for control of termites.
Invention is credited to ALVES, SERGIO BATISTA, STIMAC, JERRY L..
Application Number | 20010006632 09/156011 |
Document ID | / |
Family ID | 22020887 |
Filed Date | 2001-07-05 |
United States Patent
Application |
20010006632 |
Kind Code |
A1 |
STIMAC, JERRY L. ; et
al. |
July 5, 2001 |
NOVEL METHODS AND MATERIALS FOR CONTROL OF TERMITES
Abstract
The subject invention provides materials and methods for control
of termites.
Inventors: |
STIMAC, JERRY L.;
(GAINESVILLE, FL) ; ALVES, SERGIO BATISTA; (SAN
PAULO, BR) |
Correspondence
Address: |
SALIWANCHIK LLOYD & SALIWANCHIK
A PROFESSIONAL ASSOCIATION
2421 N.W. 41ST STREET
SUITE A-1
GAINESVILLE
FL
326066669
|
Family ID: |
22020887 |
Appl. No.: |
09/156011 |
Filed: |
September 17, 1998 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60059104 |
Sep 17, 1997 |
|
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Current U.S.
Class: |
424/93.5 ;
424/405 |
Current CPC
Class: |
A01N 63/30 20200101 |
Class at
Publication: |
424/93.5 ;
424/405 |
International
Class: |
A01N 063/04; A01N
063/00 |
Claims
1. A method for controlling termites, said method comprising
applying Beauveria bassiana onto said termites, or their
surroundings, wherein said Beauveria bassiana has the activity
against termites characteristic of Beauveria bassiana No. 447 (ATCC
20872).
2. The method, according to claim 1, wherein said Beauveria
bassiana is incorporated into a bait.
3. The method, according to claim 2, wherein said bait comprises a
food source for termites.
4. The method, according to claim 1, wherein said Beauveria
bassiana is applied as a liquid spray.
5. The method, according to claim 1, wherein said Beauveria
bassiana is applied as a powder.
6. A composition for the control of termites wherein said
composition Beauveria bassiana having the activity against termites
characteristic of Beauveria bassiana No. 447 (atcc 20872).
7. The composition, according to claim 6, wherein said bait
comprises a food source for termites.
8. The composition, according to claim 6, which is a liquid.
9. The composition, according to claim 6, which is a powder.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This applicationclaims priority from provisional application
U.S. Ser. No. 60/059,104, filed Sep. 17, 1997.
BACKGROUND OF THE INVENTION
[0002] The annual estimated costs of termite damage and control in
the United States increased from $100 million in 1967 to $1.02
billion in 1986. Among the 30 species of termites reported to be of
economic importance in the U.S., five species are considered to
have the most significant impact, partly because of their wide
distribution. These species include the drywood, or powderpost,
termites Cryptotermes brevis, in the southeastern U.S. and Hawaii,
and Incisitermes minor, which is found in Texas, the southwest, and
in the Rocky Mountains and westward. The remaining three species
are the subterranean termites Coptotermes formosanus, in the
southeast and Hawaii, Reticulitermes hesperus in the northwest and
California, and R. flavipes throughout the U.S. east of the Rocky
Mountains. In addition to the termites listed above, other species
may cause significant damage in more localized areas.
[0003] Subterranean termites most often enter structures from the
surrounding soil to feed on wood, or other cellulosic material, of
the structure and its contents. Subterranean termites construct an
extensive foraging gallery beneath the soil surface. A single
colony may contain several million termites with foraging territory
extending up to 300 feet (Su, N. Y., R. H. Scheffrahn [1988]
Sociobiol. 14(2):353-359). Since subterranean termites are cryptic
creatures, their presence is not normally known until after some
damage, foraging tubes, or live termites such as swarmers, are
found. Some subterranean termites are known to forage beneath an
object on the soil surface (Ettershank, G., J. A. Ettershank, W. G.
Whitford [1980] Environ. Entomol. 9:645-648).
[0004] Control methods for structural infestations of termites
varies with the ecology of the different species. Currently, there
are two basic approaches for the control of subterranean termites:
preventive control and remedial control. In general, preventive
measures include the use of wood treated with various repellant
chemicals; metal shields between the foundation supports and
buildings that either act as barriers, or as a detection method
when termites construct visible tubes around the shields; and the
creation of chemical barriers by treating the soil under the
building foundation, before and after construction, with
long-residual termiticides. A layer of basaltic rock particles
placed under foundations has been used as a physical barrier to
stop the penetration of subterranean termite tunneling. Removal of
lumber scraps and sites that accumulate water also discourage the
establishment of termite colonies.
[0005] Remedial control methods can entail removal of infested wood
and replacement with treated wood; drilling and injecting
insecticides into small, localized infestations; fumigation of
structures with widespread infestations; and use of slow-acting
insecticides (Su, N. -Y., M. Tamashiro, and M. I. Haverty (1987) J.
Econ. Entomol. 80:1-4). Aerial colonies of C. formosanus can be
eliminated by the removal of their moisture source.
Post-construction soil application of termiticides to eliminate
subterranean termite colonies, while commonly attempted, is of
limited success (Su, N. -Y., and R. H. Scheffrahn (1990a) J. Econ.
Entomol. 83:1918-1924).
[0006] In some of the United States, it is mandatory that the soil
underlying the foundation of newly constructed buildings be
pre-treated with a termiticide to prevent termite infestation.
Pesticide is typically sprayed over and into the soil prior to
construction. This pre-construction treatment produces a horizontal
barrier beneath the building. Because of the lack of communication
between pesticide applicator and construction workers, the barrier
often loses its continuity during the construction. Moreover, the
currently available soil termiticides tend to lose their biological
activity after five or more years to the extent that the treated
soil is no longer effective against termite invasion. Established
termite colonies in the soil may then invade the structure if
additional chemical is not applied beneath and around the
structure.
[0007] When a house or other building is infested by subterranean
termites, efforts are made to create a continuous barrier beneath
the building in the soil where the subterranean termites are
provided access to the building. A common method of creating this
barrier is to introduce termiticide around a building foundation by
injection into soil underlying concrete foundations, drenching the
soil surrounding the building perimeter, or a combination of both.
This type of post-construction treatment is labor-intensive and may
not adequately produce a continuous barrier (Frishman, A. M., B. L.
Bret [1991] Pest Control 59(8):48, 52, 54, 56; Frishman, A. M., A.
St. Cyr [1988] Pest Control Technology 16(4):33, 34, 36).
[0008] Other remedial treatments include spot treatments such as
dusting or injecting termiticides within the walls of the building.
Robert Verkerk has described arsenic trioxide dust treatment using
termite lures (Verkerk, R. [1990] Building Out Termites, Pluto
Press Australia Limited, P.O. Box 199, Leichhardt, NSW 2040).
Verkerk describes the use of stakes or blocks of termite
susceptible timber to lure termites after the stakes or blocks have
been placed near a known termite problem. Once termite activity is
observed, arsenic trioxide is injected. Alternatively, a portion of
the termites may be dusted with arsenic trioxide.
[0009] The effectiveness of the former standard soil termiticides,
chlordane and heptachlor, precluded substantial research in
alternative termite control methods. Since their withdrawal from
the market in 1987, replacement termiticides include chlorpyrifos
(Dursban TC) and isofenphos (Pryfon 6), cypermethrin (Demon TC),
permethrin (Dragnet FT), fenvalerate (Tribute) and imidacloprid
(Premise). Given the loss of chlordane and heptachlor, alternative
control measures, such as the use of toxicant and insect growth
regulator baits, are being researched (Su, N. -Y., and R. H.
Scheffrahn (1990b) Sociology 17:313-328).
[0010] A wide variety of termite control methods have been
proposed. Japanese patent application Nos. 61-198392 and 63-151033
describe wooden vessels specifically designed to "attract" termites
as part of a monitoring procedure. In the 63-151033 application,
the termites are further exposed to a toxicant which is then
presumably carried back to the nest in hopes of killing the queen
via trophallaxis or food exchange.
[0011] Australian Patent No. 1,597,293 (the '293 patent) and a
corresponding Great Britain Patent, No. 1,561,901, describe a
method which involves mixing insecticide with a food matrix
comprising cellulose and a binding agent.
[0012] One termite control method comprises placing a highly toxic
material, such as an arsenic-containing dust, at a site of
infestation in the hope that this will directly control an
effective number of termites at the site and also other termites
back in the colony.
[0013] Elaborate schemes of pipes to convey liquid termiticides
under and surrounding buildings have also been proposed for termite
control. It has been suggested that these liquid termiticides may
be dispensed into the soil surrounding and below the building
through these pipes to provide a continuous barrier to the
incursion of termites. This method requires a large quantity of
termiticides in order to saturate the soil surrounding the
building.
[0014] U.S. Pat. No. 5,027,546 describes a system intended for use
on above ground termites, i.e., drywood termites, which controls
termites by freezing with liquid nitrogen. U.S. Pat. No. 4,043,073
describes a method which attempts to circumvent the problem of
repeated application of pesticide. The described method functions
by "encapsulating" the insecticide, thus making it more persistent.
The overt use of pesticides and their persistence in the
environment are not remedied by this system. Another proposed
system which fails to alleviate the problem of transferring
insecticide directly into the soil is U.S. Pat. No. 3,624,953. This
method employs a reservoir of insecticide wherein the vapors of the
insecticide are permitted to permeate the soil surrounding the
reservoir. Thus, exposure of the environment with toxic substances
is not avoided by using this method.
[0015] Toxicants which have less environmental effect and which
show activity against termites are known (Su, N. Y., M. Tamashiro,
M. Haverty [1987] J. Econ. Entomol. 80:1-4; Su, N. Y., R. H.
Scheffrahn [1988] Florida Entomologist 71(1):73-78; Su, N. Y., R.
H. Scheffrahn [1989] J. Econ. Entomol. 82(4):1125-1129; Su, N. Y.,
R. H. Scheffrahn [1990b] Sociobiol. 17(2):313-328; Su, N. Y. [1991]
Sociobiol. 19(1):211-220; Su, N. Y., R. H. Scheffrahn [1991] J.
Econ. Entomol. 84(1):170-175; Jones, S. [1984] J. Econ. Entomol.
77:1086-1091; Paton, R., L. R. Miller [1980] "Control of
Mastotermes darwiniensis Froggatt (Isoptera: Mastotermitidae) with
Mirex Baits," Australian Forest Research 10:249-258; McHenry, W.
E., U.S. Pat. No. 4,626,528; Henrick, C. A., U.S. Pat. No.
5,151,443).
[0016] It should be noted that attractants other than water for
termites have been investigated. For example, the extract from
brown-rot fungi chemically resembles the trail-following pheromones
of termites. Natural pheromones, however, are species- and even
colony-specific. A pheromone that is "attractive" to one species or
colony of termites may repel termites of other species or colonies.
It is of uncertain value, therefore, to incorporate pheromone
mimics (such as the brown-rot fungi extract) in a bait, especially
if a bait is to be used against a wide range of termite
species.
[0017] Reported natural enemies of termites consist of general
predators such as birds, lizards, spiders, ants, and centipedes.
Parasitic mites are known to parasitize termites in laboratory
colonies. Phorid and calliphorid flies have been reported as
parasitoids of African and southeast Asian termites. Insect
parasitoids of North American termites have not been recorded.
Nematodes have been found in termites, and a few species have been
evaluated as potential control agents. However field efficacy by
these nematodes was not adequate.
[0018] Several microbial pathogens have been isolated from termites
(Sands, W. A. (1969) "The associaiton of termites and fungi, pp.
495-524, In K. Krishna & M. F. Weesner [eds.] Biology of
Termites Vol. 1, Academic Press, New York; Beal, R. H. and A. G.
Kais (1962) J. Invert. Path. 4:488-489; Kimbrough, J. W. and B. L.
Thome (1982) Mycologia 74:201-209. Bioassays of Metarhizium
anisopliae (Hanel, H. (1982) Z. ang. Ent. 94:237-245; Lai, P. Y.,
M. Tamashiro, J. K. Fujii (1982) J. Invert. Path. 39:1-5;
Fernandes, P. C. (1991) Microbial control of Cornitermes cumulans
(Kollar, 1832) (Isoptera-Termitidae) with Beauveria bassiana
(Bals.) Vuill. and Metarhizium anisopliae (Metsch.) Sorok., Ph.D.
dissertation. Univ. So Paulo, Piracicaba, 114 p.; Beauveria
bassiana (Lai et al. (1982) supra; Fernandes (1991) supra;
Gliocladium virens (Kramm, K. R., D. F. West (1982) J. Invert.
Path. 40:7-11; species of Entomophthora (Yendol, W. G. and J. D
Paschke (1965) J. Invert. Path. 7:414-422; Hanel (1982) supra, and
Bacillus thuringiensis (Smythe, R. V. and H. C. Coppel (1965) J.
Invert. Pathol. 7:423-426) have all shown that termite mortality
can occur under laboratory conditions. A field application of M
anisopliae resulted in recoveries of infected termites, but it did
not eliminate the colonies (Hanel and Watson 1983). While potential
for microbial control is evident in the laboratory, efficacy under
field conditions has generally been lacking.
[0019] A United States patent has been granted for a fungus showing
high activity against fire ants, U.S. Pat. No. 4,925,663. This
isolate, designated Beauveria bassiana isolate No. 447, was
deposited in a public repository. This isolate is also active
against cockroaches (WO 95/25430). The subject invention concerns
the new use of B. bassiana No. 447 for control of termites.
BRIEF SUMMARY OF THE INVENTION
[0020] The invention disclosed and claimed herein relates to a
method for controlling termites. Specifically, the subject
invention concerns the use of a highly virulent Beauveria bassiana
isolate to control termites. Specifically exemplified herein are
formulations containing B. bassiana isolate No. 447. This isolate
advantageously shows unexpectedly high virulence against termites
and does not produce the environmental hazards associated with
chemical control agents.
[0021] The fungal biopesticides described herein can be applied to
termites in their normal habitats. The fungus may be applied, for
example, directly to the termites, or applied to their
surroundings, or anywhere that termites are a problem. In a
preferred embodiment, the fungus is applied alone to termites
through a bait but also could be applied in conjunction with other
agents that cause stress on individuals or the colony.
[0022] The subject invention also includes mutants of the
exemplified isolate which substantially retain the high virulence
of the parent strain.
BRIEF DESCRIPTION OF THE DRAWING
[0023] FIG. 1 shows cumulative percent mortality of subterranean
termites exposed to B. bassiana isolate No. 447.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The subject invention concerns the use of fungal biocontrol
agents to control termites. Specifically exemplified herein is the
use of Beauveria bassiana isolate No. 447 to control subterranean
termites.
[0025] A biologically pure culture of Beauveria bassiana No. 447
has been deposited in the American Type Culture Collection (ATCC),
12301 Parklawn Drive, Rockville, Md. 20852 in conjunction with U.S.
Pat. No. 4,925,663. The deposit information and accession numbers
are as follows:
1 Culture Accession Number Deposit Date Beauveria bassianaNo. 447
ATCC 20872 December 29, 1987
[0026] The entomopathogenic fungus Beauveria bassiana (Bals.)
Vuill. is a Deuteromycota: Hyphomycetes. The genus Beauveria Vuill.
is distinguished from other genera by having conidigenous cells
with an apical denticulate root with zig-zag appearance. Conidia
are globulose to subglobulose, equal to or less than 3.5
micrometers in diameter. The sexual stage is probably Cordyceps.
The species Beauveria bassiana has spherical, not ellipsoid,
conidia with conidiophores forming dense bunches.
[0027] Formulations.
[0028] In a preferred embodiment, the formulation comprises a bait
having the fungal biocontrol agent and a food component.
Optionally, the formulation may also comprise an attractant. The
preferred formulationis non-repellantand includes a food source so
that termites will forage and recruit other nestmates for foraging
activity. In a preferred embodiment, the formulation of the subject
invention advantageously adheres to the body of the termite,
thereby facilitating colonization of the pest by the fungal
biocontrol agent.
[0029] In one embodiment of the subject invention B. bassiana
isolate is applied in conjunction with another termiticide.
Preferably, the other termiticide is applied at a concentration or
rate which, if used alone, does not result in complete control of
the termites. Thus, the activity of B. bassiana together with
sub-lethal doses of a termiticide can be used to achieve effective
termite control.
[0030] Following are examples which illustrate procedures,
including the best mode, for practicing the invention. These
examples should not be construed as limiting. All percentages are
by weight and all solvent mixture proportions are by volume unless
otherwise noted.
EXAMPLE 1
[0031] Preparation of the Fungus
[0032] The subject fungus can be produced in trays with a
rice-based medium. An isolate of fungal inoculum is used to
initiate the growth of the fungus in the trays.
[0033] The initial inoculum is prepared in petri dishes. The pure
spores are then transferred into jars containing sterile white rice
without skins.
[0034] The medium for the trays is prepared as follows:
[0035] 1. The rice is pre-cooked for 10 minutes.
[0036] 2. 750 grams of cooked rice is placed in polyethylene bags
and sterilized in an autoclave at 120.degree. C. for 30
minutes.
[0037] 3. Within a laminar flow hood, one teaspoon of spores and
rice from the inoculum jars is added to each bag of prepared
sterile medium.
[0038] 4. Each bag is closed tightly by folding and stapling the
open end.
[0039] 5. The bags are transferred to a sterile room with positive
pressure, temperature at 24.0-27.0.degree. C., relative humidity
above 70%, and 16 hours photophase. This room is known as the
"environment room."
[0040] After 3 days in the environment room, bags containing
mycelia are selected and their contents are transferred to plastic
trays. The size of the trays is such that each tray will
accommodate the contents of 2-3 bags. The trays and their contents
are left in the environment room for 8-10 days. At the end of the
8-10 day period, the trays are transferred to a room with a cool
(10-20.degree. C.) current of clean air. The trays are left in this
room until the cool air has dried the rice and fungus mixture.
[0041] The uncontaminatedtrays of rice covered with fungus can be
harvested and prepared for application or storage. If the fungus
will be applied to termites within 1-2 weeks after production,
conidia can be collected by shaking and sieving. The resulting
powder contains spores and some mycelia, and can be applied
directly to termites or used to prepare a formulation as a liquid,
powder, or bait.
[0042] If the fungus is to be stored for a short period of time,
the mixture can be mixed with cornstarch or talc and placed into
sterile plastic containers sealed tightly and stored in a
refrigerator at 4.degree. C. or in a room with a temperature range
of 10-25.degree. C. and no direct sunlight. A temperature of
-7.degree. C. is better for longer storage times. The high
virulence of B. bassiana can be compromised by bacterial or fungal
contamination. Therefore, throughout the preparation of the fungus,
great care must be taken to maintain the sterility of all
instruments and equipment.
[0043] The fungus-containing product can be applied to termites and
their nests as a liquid, powder, or put out as a baited trap for
the termites to forage, become infected, and carry inoculum back to
the nest.
EXAMPLE 2
[0044] Spray Application
[0045] Spraying can be used for treating individual termites or
small groups of these pests. A fungal suspension containing
1.0.times.10.sup.7 to 1.0.times.10.sup.9 spores per milliliter of
water can be sprayed on the termites using an airbrush or other
means as an applicator.
EXAMPLE 3
[0046] Powder Application
[0047] A fungal spore and mycelia mixture can be mixed with
cornstarch or talc and applied to the pests' surroundings as a dry
powder.
[0048] The powder is prepared as in Example 1 above. The sieved B.
bassiana powder which contains the rice, spores, and mycelia is
mixed with cornstarch or talc. Application of this powder to the
nests or directly to the pests can facilitate rapid and widespread
fungal growth within the nest or on the pest.
[0049] The application can be accomplished using a pressurized air
applicator with an attachment that distributes the mixtures into
cracks and crevices of a termite-inhabited building. During and
following application, termites covered with white powder will be
observed. These infected pests will die within 1-5 days, and the
spores they produce will be infective to other termites. Active
spores will remain in the surroundings at the nest site, thereby
providing inoculum to infect other termites.
EXAMPLE 4
[0050] Baited Trap Application
[0051] In a preferred embodiment, the fungal powder can be used in
a trap in which entryways are laced with fungal inoculum.
Preferably, fungal spores are utilized. A bait attractant contained
within the trap will be foraged by termites and the foragers will
become infected. These infected individuals will return to the nest
and thereby introduce the fungal disease into the nest. Various
attractants, including pheromone compounds, are well known to those
skilled in this art. A quantity of 0.5-2.0 grams of fungal mixture
containing spores and mycelia should be contained in each trap. The
number of traps used in an area will depend on the level of
infestation.
EXAMPLE 5
[0052] Control of Termites with B. bassiana No. 447.
[0053] Termites (Reticulitermes spp.) were treated with B. bassiana
447. Using a spray tower, conidial suspensions were applied to four
or five replicates of 20 worker termites. Daily mortalities were
recorded for 15 days and were collected daily, surface sterilized
and plated to determine levels of sporulation.
[0054] Tests were also conducted with powder formulations
consisting of 1 or 10% conidia of different fungal isolates. Twenty
Reticulitermes termites were placed in each of 5 petri dishes
containing 0.02 g of the formulations. After a 24-h exposure
period, the insects were transferred to plastic containers and were
observed daily. Cadavers were removed, surface sterilized and
plated to allow development of infecting fungi.
[0055] When formulations containing 10% of conidia in cornstarch
were used, mortality of the insects occurred at high levels at 1-2
days after treatment for all strains of fungi tested (FIG. 1). B.
bassiana isolate 447 killed all the treated insects by the second
day after initial exposure to fungal material.
[0056] Because the powder formulations were so efficient in the
first test against termites, a second experiment was conducted with
lower doses of the fungi. Total mortality of termites was also
obtained when insects were exposed to formulations containing 1%
conidia of the fungal isolates. Mortality increased at a slower
rate than when the 10% formulations were used, however, all insects
died within 5 days after treatment. Mortality peaked at 3 days
after treatment. Sporulation on cadavers was about 88%.
[0057] It should be understood that the examples and embodiments
described herein are for illustrative purposes only and that
various modifications or changes in light thereof will be suggested
to persons skilled in the art and are to be included within the
spirit and purview of this application and the scope of the
appended claims.
* * * * *