World Congress of Malacology Antwerp ... - Unitas Malacologica

epresenting time ranges from the HPLC output were reconstituted in a saline vehicle and loaded into
hypodermic syringes. In controlled mating trials, sibling virgin snails were mated with each other.
One snail in each pair was injected with coded sample #1 and the partner was injected with coded
sample #2. One week after the mating, allosperm in the spermathecal tubules were labelled by DNA
staining. The relative efficacy of the two samples was then measured by counting individual
allosperm using fluorescent microscopy.
From a series of binary tests as described above, we have identified a small region of the HPLC
profile that produces a statistically significant effect in our bioassay. Interestingly, the results suggest
that the bioactive substance increases allosperm survival by making it easier for the spermatozoa to
become embedded in the epithelial walls of the storage tubules. Further testing should allow us to
identify the bioactive substance.
Mortality to the giant African snail Achatina fulica Bowdich, 1822
and non-target snails using select molluscicides
Ciomperlik, Matthew A. 1 ; Robinson, David G. 2 ; Gibbs, Ian H. 3 ; Fields, Angela 4 ; Stevens,
Timothy 5 ; Taylor, Bret M. 4
1. USDA APHIS PPQ CPHST, Pest Detection and Management Laboratory, 22675 N. Moorefield,
Rd., Edinburg, TX 78541, USA,
Email: Matthew.A.Ciomperlik@aphis.usda.gov
2. USDA APHIS PPQ NIS, Academy of Natural Sciences, 1900 Ben Franklin Parkway, Philadelphia,
PA 19103, USA,
Email: robinson@acnatsci.org
3. Ministry of Agriculture and Rural Development, Christ Church, Graeme Hall, Barbados,
Email: ianhgibbs@yahoo.com; bmtay@hotmail.com
4. University of the West Indies, Cave Hill Campus, P.O. Box 64, Bridgetown, Barbados,
Email: afields@uwichill.edu.bb
5. USDA APHIS PPQ Eastern Region, 1815 Gardner Drive, Wilmington, NC 28405, USA,
Email: Tim.N.Stevens@aphis.usda.gov
Laboratory bioassays and caged field trials were conducted to compare concomitant molluscicide
effects on three development stages of the giant African snail (GAS) (Achatina fulica) and three nontarget
snail species in Barbados. Nine commercially available molluscicides, diatomaceous earth, and
a kaolin clay product (Surround WP) were evaluated in this study. High levels of mortality to neonate
GAS were seen in all the molluscicide treatments except for Surround, diatomaceous earth, and
Sluggo pellets. In field trials, Deadline, Durham granules, Metarex, and Orcal pellets caused the
highest rates of mortality to juvenile GAS. For adult GAS several molluscicides including Blitzem,
Deadline, Durham Granules, Mesurol 75W, Metarex, Orcal pellets, and Slugfest caused greater that
95 per cent mortality in laboratory bioassays. Field trials showed that Durham granules and Slugfest
yielded the highest mortality rates. Sluggo pellets, touted as an environmentally safe molluscicide,
did not cause significant mortality to juvenile and adult GAS in our field trials.
The majority of the molluscicides tested in our trials were equally or more lethal to Pleurodonte
isabella (Férussac, 1821), Bulimulus guadalupensis (Bruguière, 1789), and Zachrysia provisoria
(Pfeiffer, 1858) than GAS. Our results suggest that the potential impact on non-target snails during
control or eradication programs may be significant, causing substantial mortality regardless of what
brand, active ingredient, or formulation is used.
34