Florida GALS Eradication Program Methods Development.
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Transcript of Florida GALS Eradication Program Methods Development.
Objectives• Chemical Control Techniques
– Molluscicide bait efficacy testing– Effective soil drench development
• Trap Development– Most effective trap design– Most effective attractants
• Nematode Detection– Is Angiostrongylus cantonensis widespread in Florida?
• Biological Studies– Time to reproductive maturity (defined by first egg laying event)– Growth rate over time and “natural” survivability– Clutch size and frequency of egg laying and effect of burial depth on egg hatch– Effect of population density on the animals– Source of chirality in A. fulica using traditional crosses and molecular techniques.
Molluscicide Evaluation• Kemp, N. J. and P.F. Newell. 1985. Laboratory observations on the
effectiveness of methiocarb and metaldehyde baits against the slug Deroceras reticulatum (Müll). J. Molluscan Studies 51: 228-229.
• Smith, T. R., J. White-McLean, K. Dickens, A. Howe and A. Fox. 2013. Efficacy of four molluscicides against the giant African snail, Lissachatina fulica Bowdich, (Gastropoda: Pulmonata). Florida Entomologist 96: 396-402.
• Ciomperlik, M.A., D.G. Robinson, I.H. Gibbs, A. Fields, T. Stevens and B.M. Taylor. 2013. Mortality to the giant African snail, Lissachatina fulica (Gastropoda: Achatinidae), and non-target snails using select molluscicides. Florida Entomologist 96: 370-379.
Metaldehyde Products With Residential Use Labels
• Molluscicides incorporated into the program– Bug-Geta – 3.25%
pellet metaldehyde – Hi-Yield Snail and Slug
Killer – 3.25% pellet metaldehyde
– Other 3.25% products available
Experimental Use Permit (EUP) Exemption Work
• Molluscicides Tested– SlugFest – 25% liquid
metaldehyde– Slugger – 4% mini-
pellet metaldehyde– Durham – 7.5%
granule metaldehyde
Special Local Needs Label Update
• EUP exemption results accepted by AES and EPA
• SLN label requests – SlugFest (OrCal), Slugger (OrCal) and Deadline (AMVAC)
• Durham granules delayed – AMVAC unable to add bittering agent to a sand-based product (required by EPA)
• OrCal is working to develop a finer granule with bittering agent by further milling the mini-pellets
Soil Drenches• Natural Oils and Extracts:
caraway, cedar, cinnamon, clove, coffee, garlic, onion, mustard, and rosemary
• Nerve and Muscle Disruptors:thevetin and peruvoside (lucky nut plant), caffeine, digitoxin, oleandrin, cardiac glycosides and oxalates (too toxic?)
• Commercial Molluscicides: Pure’N’Natural Snail and Slug Away, Georgia Organic Solutions Neem 7-way, Global Aqua Solutions EF-211
• Traditional Drenches for Other Pests:imidacloprid, clothianidin, pyrethrins, fipronil, etofenprox, chlorothalonil, spinosad
Rat Lungworm Testing
• Currently testing for:– Angiostrongylus
cantonensis• Could possibly
include the following species in the future: – A. costaricensis– A. dujardini– A. malaysiensis– A. vasorum
http://dpd.cdc.gov/dpdx/html/ImageLibrary/A-F/Angiostrongyliasis/body_Angiostrongyliasis_il5.htm
• Quantitative PCR• Traditional
identification using light microscopy
Rat Lungworm Testing Results
• Over 600 snails tested to date
• ~30 specimens can be tested per week
• Samples tested from 17 of the 21 Cores
• RLW detected in 7 Cores: 1, 2, 4, 5, 7, 12 and 15.
Biology Studies
• Egg Burial depth study
• Growth rate over time
• Reproductive Studies
• Self-fertilization rate
• Chirality Breeding Study
(dominant / recessive)
Growth Rates
20 40 60 80 100 120 140 160 180 20010.0
30.0
50.0
70.0
90.0
110.0
130.0Mean Snail Height
Days after hatch
Hei
ght (
mm
)
Single Lettuce
Single Synthetic DietPaired Lettuce
Paired Synthetic Diet
Single Lettuce
Single Synthetic Diet
Paired Lettuce
Paired Synthetic Diet
Days after Hatch
Height (mm) Width (mm) Whorls Weight 0.0
20.0
40.0
60.0
80.0
100.0
120.0
140.0
160.0146
81.1
44.1
6.76
56.02
139.2
91.3
49.9
7.01
90.26
Synthetic Diet
Lettuce
Average Time to First Egg Laying Average Parental Size
Reproductive Potential – Lab Studies
Time of First Egg Laying Parental Size
Months after Hatch Height (mm) All paired (2 snails
per cage) treatments Average: 4.8 86 (3.4 inches)
Minimum: 4.1 64 (2.5 inches)
N = 80
Reproductive Potential – Lab Studies• Average eggs/month = 730– Average egg viability = 51.3%– Average clutches/month = 2
• Greatest number of eggs produced by one cage– 5,146 eggs (10 clutches) in about 4 months. – 1 clutch tested for viability = 80%
• Largest Clutches: – 1082 eggs – 732 eggs (96.7% viable)
Self-Fertilization
Observations: Single, Lettuce =Non-viable Eggs
Paired, Lettuce = Viable Eggs
Viable Eggs!
~3 months
later
However:Single, Diet =
Key Biological Factors For the Program
• Self fertilization = Yes (average egg viability)• Sexual maturity = 4 months old (2.5 inches)• Adults can produce up to 625 eggs per month
(average 365 with 50% viability)• Eggs were observed hatching 26 days after egg
laying (average 5 – 7 days)• Neonate survival underground without food =
97 days• Possible period underground ≈ 120 days (4
months)