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ARS Home » Pacific West Area » Hilo, Hawaii » Daniel K. Inouye U.S. Pacific Basin Agricultural Research Center » Tropical Crop and Commodity Protection Research » Research » Research Project #440917

Research Project: Identification of Giant African Snail Odors to Aid Detector Dog Training

Location: Tropical Crop and Commodity Protection Research

Project Number: 2040-43000-018-016-I
Project Type: Interagency Reimbursable Agreement

Start Date: Aug 1, 2021
End Date: Aug 31, 2022

Objective:
1. Optimize methods to identify giant African snail odor profile using analytical chemistry detection methods. 2. Select a target group of compounds as candidates to develop a synthetic training tool. 3. Transfer methodology to process sample and identify gastropod odor profiles to ARS cooperator in Hilo, HI. 4. Validate that the target group of compounds is present in wild snail populations. 5. Determine whether the identified giant African snail odor profile differ from other land gastropod species found in South Florida and Hawaii 6. Develop a synthetic training tool if the compounds unique to giant African snail odor profile are commercially available 7. Initiate development of a testing protocol with national and local canine staff

Approach:
1. The volatile profile of snails of all age classes, eggs and mucus will be determined with two methods in order to obtain a wider range of compounds: 1) distillation of samples followed by injection into a gas chromatography – mass spectrometer (GC-MS), and 2) agitated thermal desorption SPME-GC-MS. Additionally the profile of other established gastropod species will be obtained to confirm that the target compounds are unique to giant African snails as well as to obtain a target set of compounds to identify other gastropod species not established in the continental U.S. 2. Laboratory Colonies Miami: Giant African snails used for the experiments will be maintained by Florida Department of Agriculture and Consumer Services, Miami, FL. All sample collection will be done under quarantine protocols in the facility designated to hold the snails. Snails will be reared in plastic containers with 2 cm soils on the bottom to promote oviposition. The snails will be fed organic lettuce and carrots and supplemented with a calcium source. Additional established gastropods, Bulimulus guadalupensis, Leidyula floridana, Bradybaena similaris and Zachrysia provisoria will be field collected in Miami, FL and reared following the same protocol for giant African snails. 3. Field Collection Hilo, Hawaii: Wild snails and eggs will be obtained from three different locations known to have large numbers of snails. The sample will be brought back to the lab for immediate processing and odor collection or frozen. The same locations will be searched for invasive species known to be established in Hawaii, including Parmarion martensi and Vernicella cubensis. The other species will be collected and processed as described for giant African snail. 4. Mucus Sample Collection: The mucus will be collected directly from the colony and wild snails and other gastropods by gently scrapping the snail foot with a glass vial. The mucus will then immediately be prepared for volatile collection or frozen. 5. Volatile collection and chemical analyses: Odors and mucus from the live and frozen snail treatments will be obtained using distillation and SPME sampling of agitated and heated (80°C) samples analyzed using agitated thermal desorption SPME-GC-MS identified using retention indices and library matches and confirmed by comparison of their linear retention indices against the authenticated standards. Relative percentages will be given by GC-MS results. 6. Develop a synthetic tool for canine training: Similarities and the most abundant volatile compounds between Floridian and Hawaiian populations will be selected and commercially available compounds will be purchased to prepare a synthetic blend to be used for canine training. In addition a containment device will be used that will release small amounts of the odor and will allow the training aids last for an extended period.