Source: UNIVERSITY OF FLORIDA submitted to
MECHANISM FOR BIOSYNTHESIS, RELEASE AND DETECTION OF VOLATILE CHEMICAL IN PLANT-INSECT INTERACTIONS
Sponsoring Institution
State Agricultural Experiment Station
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0187702
Grant No.
(N/A)
Project No.
FLA-ENY-03935
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Dec 8, 2000
Project End Date
Aug 31, 2002
Grant Year
(N/A)
Project Director
Boucias, D. G.
Recipient Organization
UNIVERSITY OF FLORIDA
G022 MCCARTY HALL
GAINESVILLE,FL 32611
Performing Department
ENTOMOLOGY & NEMATOLOGY
Non Technical Summary
(N/A)
Animal Health Component
20%
Research Effort Categories
Basic
80%
Applied
20%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2110910113010%
2110920113010%
2111440200010%
2111460200010%
2151480100010%
2151510100030%
2161710200020%
Goals / Objectives
Determine the mechanisms by which plants respond to insect herbivore damage and biosynthesize and release volitile chemicals that attract insect parasitoids.
Project Methods
Cotton, corn and other plant species will be damaged by herbivorous insects, or treated with oral secretions of herbivorous insects or elicitors isolated and identified from the oral secretions of herbivorous insects. Volatile compounds released by plants treated in various ways will be collected, analyzed and the constituents identified. The foraging behaviors of natural enemies (parasitoids) of the herbivores in response to the plant volatiles will be investigated. The biochemical mechanisms by which plants respond to herbivore produced elicitors will be investigated to include endogenous plant signaling pathways. Also, other factors that may affect the tritrophic interactions will be studied. The goal is to understand these interactions and to use this knowledge to develop more effective strategies for biological control of insect pests.

Progress 10/01/05 to 09/30/06

Outputs
The effectiveness of two lures for trapping the small hive beetle, Aethina tumida, by means of in-hive traps was tested by field trials in apiaries located in Florida, Delaware, and Pennsylvania during 2003-2005. Both lures included a mixture (pollen dough) consisting of bee pollen and commercial pollen substitute formulated with or without glycerol and honey. Before it was used in the traps, the dough was conditioned either by the feeding of adult small hive beetles or by inoculation with the yeast Kodamaea ohmeri (NRRL Y-30722). Traps baited with conditioned dough captured significantly more beetles than unbaited traps, and traps positioned under the bottom board of a hive captured significantly more beetles than traps located at the top of a hive. In fact, baited in-hive bottom board traps nearly eliminated the beetles from colonies at a pollination site in Florida. However, when these honeybee colonies were moved to an apiary, trap catch increased markedly over time, indicating a resurgence of the beetle population produced by immigration of beetles from nearby hives or emerging from the soil. In tests of yeast-inoculated dough against unbaited traps in three Florida apiaries during 2006, baited bottom board traps captured significantly more beetles than unbaited traps, demonstrating the effectiveness of yeast-inoculated dough as a lure and its potential as a tool in managing the small hive beetle.

Impacts
The results of this study show that pollen dough conditioned by the feeding of adult A. tumida or inoculated with yeast associated with the beetle is an effective lure for trapping beetles. Furthermore, bottom board traps baited with yeast-inoculated pollen dough and containing a soapy solution showed considerable potential as a monitoring tool in managing small hive beetle infestation in managed honeybee colonies.

Publications

  • Torto, B., Arbogast, RT., vanEngelsdorp, D., Willms, S., Purcell, D., Boucias, DG., Tumlinson, JH.,and Teal, PEA. 2006. Trapping of Aethina tumida Murray (Coleoptera: Nitidulidae) from Apis mellifera L. (Hymenoptera: Apidae) colonies with an in-hive baited trap. Environ. Entomol.(submitted)


Progress 10/01/04 to 09/30/05

Outputs
We have discovered that in the host-parasite interaction involving the honeybee and the small hive beetle, Aethina tumida, the honeybees alarm pheromones serve as an attractant to the beetle. Further, the beetle is a vector of a yeast species that grows on pollen in hives and produces these same honeybee alarm pheromones, optimizing the beetles recognition of bee hosts and conspecifics. Thus, the honeybee-beetle-yeast tritrophic interaction provides a fitness advantage to the beetle in host environments that favor growth of the fungus. This facilitates attraction of more beetles to the hive for reproduction, while forcing bees to abandon their hives. We conclude that this tritrophic interaction has contributed significantly to the success of the beetle since its introduction into European honeybee (EHB) colonies in the United States, which due to intense breeding over many centuries are relatively less responsive to alarm pheromones and less aggressive in repelling intruders from hives than the original host of the beetle, African honeybees.

Impacts
The trapping system for the small hive beetle has been extensively tested in hives in apiaries in Florida and Pennsylvania in collaboration with bee inspectors and beekeepers. The trapping system has shown that only a small percentage of hives tend to be heavily infested with the beetles. This information is being used to educate beekeepers on the use of the trap and control of the small hive beetle.

Publications

  • B. Torto, A. Suazo, H. Alborn, J.H. Tumlinson and P.E.A. Teal 2005. Response of the small hive beetle (Aethina tumida) to a blend of chemicals identified from honeybee volatiles. Apidologie, 36:523-532.
  • P.E.A. Teal, B. Torto, J.H. Tumlinson and D. Boucias 2005. An In-Hive trap and attractant combination for the control of the small hive beetle, Aethina tumida. US Patent pending (P.C. 0188.03).
  • B. Torto, D. Boucias, R.T. Arbogast, J.H. Tumlinson and P.E.A. Teal 2005. Honeybee alarm pheromone facilitates success of an invasive parasite. Nature (submitted).


Progress 10/01/02 to 10/01/03

Outputs
We have identified a series of food, fermentation and insect derived attractants for the small hive beetle, a serious pest of commercial apiaries in Florida. Using this knowledge we have designed and developed a trapping system that is useful for monitoring population densities and distributions of the small hive beetle. Results of our researach have allowed us to provide the apiculture industry with data on the times of the year in which the beetle is most likely to invade hives and the most probably environments in which the beetle is likely to be resident. The results enable apiculturists to determine the best place to set up hives and the times of the year in which extensive colony management to control the beetle is necessary. We continue to explore the interactions with food derived volatiles and to develop new technologies for control of this serious pest within beehives.

Impacts
Incorporation of these decision making protocols should result in increased profits for the industry. The results have been discussed with the Florida Apiculture industry at the annual meeting of the Florida Beekeepers Association.

Publications

  • No publications reported this period


Progress 10/01/01 to 10/01/02

Outputs
We have identified elicitors in the spit of seven lepidopterous larvae and a grasshopper that induce plants to produce volatile compounds. We have discovered that enzymes in the midguts of the lepidopterous larvae breakdown the elicitors into fatty acids and amino acids. We have determined that peanut plants respond to fungus infection by releasing a volatile blend that is different from the blend released when they are fed on by beet armyworm larvae. We have determined that corn seedlings respond more strongly to elicitors when they are cut than when they are intact. We have synthesized one component of the Grasshopper elicitor.

Impacts
Peanut plants infected with the white mold fungus and then attacked by beet armyworm larvae are more attractive to parasitic wasps that attack beet armyworm larvae than healthy plant damaged by the larvae. Scientists at CMAVE, USDA, ARS, Gainesville, FL, in cooperation with scientists at UF are investigating the interactions among plants, plant pathogens, and insect herbivores. Understanding the chemisty of plant-insect and plant-pathogen interactions will allow manipulation of these systems to reduce pest damage and increase crop production in an ecologically sound, environmentally safe manner.

Publications

  • No publications reported this period


Progress 12/08/00 to 08/31/02

Outputs
OUTPUTS: Colony defense by honeybees Apis mellifera is associated with a sting and mass attack, fueled by the release of alarm pheromones. As such, alarm pheromones are critically important to survival of honeybee colonies. Here we report that in the parasitic relationship between the European honeybee and the small hive beetle (SHB), Aethina tumida, the honeybee's alarm pheromones serve as an attractant to the beetle. By using comparative molecular and chemical analytical techniques, we found that SHBs infesting colonies of the African honeybee subspecies Apis mellifera scutellata, and the European honeybee subspecies Apis mellifera mellifera were vectors of identical yeast species, identified as a strain of Kodamaea ohmeri, and that this yeast species can grow on pollen in hives to produce these same honeybee alarm pheromones, thereby optimizing the beetle's recognition of bee hosts and conspecifics. Overall, these data indicate that the honeybee- beetle-yeast-pollen multitrophic interaction could provide a fitness advantage to the beetle in honeybee environments that promote this interaction, by facilitating attraction of more beetles to the honeybee colony for reproduction, while forcing bees to abandon their hives. It thus appears that unlike African honeybees, the environment of the European honeybee colony provides the optimal conditions to readily promote this unique multitrophic interaction, thereby facilitating a strong parasitic relationship between the beetle, outside its native range, and the honeybee host in the United States. Plating of homogenized bodies of beetles and bees and comb swabs resulted in smooth cream-colored yeast colonies that formed pseudomycelial cells as they aged. Fatty acid profiles of yeast isolates from Florida and Kenya most closely matched the profiles of Candida krusei and C. sake, respectively. The DNA sequence of the 28S and 5.8S-ITS2 of both the Florida and Kenya isolates were 99-100% homologous to Kodamaea ohmeri. However, the ITS1 region differed between the two geographic strains. The two strains produced similar volatile profiles which were attractive to SHB and contained compounds also found in honeybee alarm pheromone. Healthy hives were also sampled and found to have multiple yeast species The effectiveness of two lures for trapping the small hive beetle, Aethina tumida, by means of in-hive traps was tested by field trials in apiaries located in Florida, Delaware, and Pennsylvania during 2003-2005. Both lures included a mixture (pollen dough) consisting of bee pollen and commercial pollen substitute formulated with or without glycerol and honey. Before it was used in the traps, the dough was conditioned either by the feeding of adult small hive beetles or by inoculation with the yeast Kodamaea ohmeri (NRRL Y-30722). Traps baited with yeast/dough captured significantly more beetles than unbaited traps, and traps positioned under the bottom board of a hive captured significantly more beetles than traps located at the top of a hive. PARTICIPANTS: Peter Teal,Nicole Benda, Steve D. Willms, and Richard T. Arbogast USDA/ARS-CMAVE, 1600/1700 SW 23rd Dr., Gainesville, FL 32608. Baldwyn Torto International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya. James Tumlinson Dept. of Entomology, Pennsylvania State University, University Park, PA 16802. Dennis vanEngelsdorp Pennsylvania Department of Agriculture, Harrisburg, PA 17110.

Impacts
In summary, our studies indicated that when SHBs, regardless of age, feed on a mixture of pollen and honey, volatiles that attract hive beetles are released, and that the release of these volatiles are due to fermentation by microorganisms including the yeast Kodamea ohmeri, previously isolated from the beetle acting on pollen (Teal et al., 2006). Research into the identities of behaviorally-active components in the volatiles could provide methods for developing synthetic lures as an alternative to the use of the yeast that can be exploited for management of the beetle. Experiments demonstrated that baited bottom board traps captured significantly more beetles than unbaited traps, demonstrating the effectiveness of yeast-inoculated dough as a lure and its potential as a tool in managing the small hive beetle. The design of the trap used and the incorporation has been patented as ameans to monitor and trap this invasive insect.

Publications

  • Torto B., D. G. Boucias, R.T. Arbogast, J. H. Tumlinson and P.E.A. Teal. 2007. Honeybee alarm pheromone facilitates success of an invasive parasite. PNAS 104:8374-8378.
  • Torto, B., Arbogast, RT., vanEngelsdorp, D., Willms, S., Purcell, D., Boucias, DG., Tumlinson, JH., and Teal, PEA. 2006. Trapping of Aethina tumida Murray (Coleoptera: Nitidulidae) from Apis mellifera L. (Hymenoptera: Apidae) colonies with an in-hive baited trap. Environ. Entomol. 36:1018-1024.
  • Torto, B., R.T. Arbogast, H. Alborn, A. Suazo, D. vanEngelsdorp, D. Boucias, J.H. Tumlinson, P.E.A. Teal 2007. Composition of volatiles from fermenting pollen dough and attractiveness to the small hive beetle Aethina tumida, a parasite of the honeybee Apis mellifera. Apidologie 38: 380-389.
  • Benda, N., Boucias, D., Torto, B., and teal, P. 2007. Detection and characterization of Kodamaea ohmeri associated with Small Hive Beetle Aethina tumida infesting honeybee hives. Apidologie (submitted).


Progress 10/01/00 to 10/01/01

Outputs
We have identified elicitors in the spit of seven lepidopterous larvae and a grasshopper that induce plants to produce volatile compounds. We have discovered that enzymes in the midguts of the lepidopterous larvae break down the elicitors into fatty acids and amino acids. We have determined that peanut plants respond to fungus infection by releasing a volatile blend that is different from the blend released when they are fed on by beet armyworm larvae. We have determined that corn seedlings respond more strongly to elicitors when they are cut than when they are intact. We have synthesized one component of the Grasshopper elicitor.

Impacts
Understanding the chemistry of plant-insect and plant-pathogen interactions will allow manipulation of these systems to reduce pest damage and increase crop production while maintaining an ecologically sound, environmentally safe agricultural system.

Publications

  • Mori, N., Alborn, H. T., Teal, P.E.A. and Tumlinson, J. H. 2001. Enzymatic decomposition of elicitors of plant volatiles in Heliothis virescens and Helicoverpa zea. J. Insect Physiol. 47:749-757.
  • Cardoza, Y., Alborn, H. T. and Tumlinson, J. H. In vivo volatile emissions from peanut plants induced by simultaneous fungal infection and insect damage. J. Chem.Ecol. 28(1): (accepted--will be published in 2002).