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
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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 nontarget 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% minipellet metaldehyde
– Durham – 7.5%
granule metaldehyde
EUP exemption Results
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
New Trap Designs
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Inexpensive
Serviceable
Toxicant-free
Vertical or Horizontal
Prevent Escape
Rat Lungworm Testing
• Currently testing for:
– Angiostrongylus
cantonensis
• Could possibly include
the following species
in the future:
–
–
–
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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)
Egg Incubation Depth
• Eggs buried at a range of depths up to 17”
• 15” seems to be near the limit
Growth Rates
Mean Snail Height
Single Lettuce
130.0
Single Lettuce
110.0
Single Synthetic Diet
Paired Lettuce
Height (mm)
90.0
Paired Synthetic Diet
Single Synthetic Diet
70.0
50.0
Paired Lettuce
30.0
10.0
0
50
100
150
200
Days after hatch
Paired Synthetic Diet
Reproductive Potential –
Lab Studies
Time of First Egg Laying
Parental Size
Months after Hatch
Height (mm)
4.8
86 (3.4 inches)
4.1
64 (2.5 inches)
All paired (2 snails
per cage)
treatments
Average:
Minimum:
160.0
146.0
140.0
120.0
139.2
100.0
81
80.0
91
60.0
56.0
90.3
44
40.0
50
20.0
6.8 7.0
0.0
Days after
Hatch
Height (mm)
Average Time to First Egg Laying
Width (mm)
Whorls
Average Parental Size
Weight
Synthetic
Diet
Lettuce
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
However:
Single, Diet =
~3
months
later
Viable Eggs!
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)
THANK YOU for your time
and attention