Pests > Pests Entities > Molluscs > Veronicellid slugs > Identification & control, Maldives



Pests > Pests Entities > Molluscs > Veronicellid slugs > Identification & control, Maldives

Pests Pests Entities MolluscsVeronicellid slugs Identification & control, Maldives

Veronicellid slug, Maldives

November 2010. Slugs were reported from Hdh. Kumundhoo island, North Maldives, and control methods were requested.

Although there was one suggestion that they might be flatworms (phylum Platyhelminthes) of the class Turbellaria, most people who responded suggested that they were Veronicellid slugs. There was an offer of identification if they were kept in the deep freeze for 1 day and then put into 70-80% ethanol.

These are veronicellid slugs, and most likely Semperula or Filicaulis species. There is also the possibility that they are Veronicella cubensis, a very serious agricultural pest and potential disease carrier, that is spreading across the Pacific Basin. Specimens should be dissected for ID.

If they are veronicellids, then the tentacles on the head should be distinctive; when the long pair of tentacles is extended, each is tipped with a dark eye. If the tentacle is touched the black eye should remain visible if it is a veronicellid slug. In other slug families, the black eye disappears as the tentacle begins to retract. In Veronicellidae the mantle completely covers the dorsum and there is no visible breathing hole. To see the foot, turn the slug over and view the ventral surface. These tropical slugs are herbivorous and can cause damage to crops.

For pictures online, see http://www.google.com/images?client=firefox-a&rls=org.mozilla:en-US:official&channel=s&hl=en&q=veronicellidae&um=1&ie=UTF-8&source=univ&ei=LUfPTKC6A4_4sAO8gfX3Aw&sa=X&oi=image_result_group&ct=title&resnum=1&ved=0CCgQsAQwAA&biw=1157&bih=963.

See also http://en.wikipedia.org/wiki/Veronicellidae. The pictures may be of the tropical leatherleaf slug, Laevicaulis alte or a similar species. See: http://en.wikipedia.org/wiki/Tropical_leatherleaf.

As for control, handpicking and application of salt was recommended. See Kalidas P, Rao CV, Ali N, Babu MK (2006) New pest incidence on oil palm seedlings in India – a study of black slug (Laevicaulus alte). The Planter, Kuala Lumpur 82(960): 181-186. Also see: www.oisat.org, a useful website for ideas about non-chemical tropical pest management. The following is suggested at http://oisat.org/pests/other_pests/snails_and_slugs/slugs/curative_control.htm:

  • Use a yeast and water solution in a shallow container to attract and drown slugs … and beer works as well. The website also has good preventive suggestions.

More about control can be found http://entnemdept.ufl.edu/creatures/misc/florida_slugs.htm – note that ducks will eat slugs.

Also note, The USDA Malacology laboratory in Philadelphia offers free identification of any veronicellid slug species, using anatomical and molecular methods. Submit samples for ID in 80% ethanol to the address below; no paperwork is required for entry into the US other than these words on the package: ???Preserved samples for scientific study; no commercial value.??? Address to: David G Robinson, USDA APHIS Malacology Laboratory, Academy of Natural Sciences, 1900 Ben Franklin Parkway, Philadelphia, PA 19103, USA.