Atividade moluscicida e ovicida do timol e domentolsobre Achatina fulica (Bowdich, 1822) e Bradybaena similaris (Férrusac, 1821), (Gastropoda, Mollusca)

Abstract

Achatina fulica, Bowdich, 1822 and Bradybaena similaris (Férussac, 1821) are speciesofexotic terrestrial snails that have spread to almost all Brazilian states. These species arecitedin the literature as parasite hosts, including species of veterinary interest. Theyarealsomentioned as agricultural pests, urban pests and causes of imbalance of native malacofauna.In areas of large infestations, these snails cause major economic losses. Besides that, theirempty shells are favorable breeding places of the mosquito Aedes aegypti, transmitterofdengue fever, chikungunya fever and zika virus, causing serious public health problems. Theproducts used to control these animals contain metaldehyde, also toxic to other animalsincluding humans, as well as causing groundwater contamination. Substances of plant origincan be selective, less environmentally toxic and biodegradable. Therefore, the objectiveofthis work was to evaluate the molluscicidal and ovicidal activity of thymol and menthol onA.fulica and B. similaris under laboratory conditions. Adult snails were collectedinfourdifferent districts of the city of Juiz de Fora, acclimated to laboratory conditions for 72hours.In the tests of thymol PA on eggs, juveniles and adults of A. fulica, concentrations of 80g/ L,75g / L, 70g / L, 65g / L, 60g / L, 50g / L, 40g / L, 30g / L, 20g / L, 10g / L, 9g / L, 8g/ L, 7g/ L, 6g / L, 5g / L, 4g / L, 3g / L, 2g / L, 1g / L, 0.9g / L 0.8g / L, 0.7g / L 0.6g / L, 0.5g/ L,0.4g / L, 0.3g / L, 0.2g / L, 0.1g / L, 0.02g / L, and 0.01g / L were used, plus 1%dimethylsulfoxide (DMSO) with distilled water heated to 60 ° C, which were sprayedintotheterrarium. In the menthol PA tests on B. similaris eggs, juveniles and adults, theconcentrations tested were 0.1g / L, 1g / L, 2.5g / L, 3g / L, 5g / L, 10g / L, 20g / Land50g/L, both with six repetitions. The first control received distilled water plus 1%DMSOandthesecond only distilled water. Thymol and menthol showed molluscicidal and ovicidal activityon the species for which they were tested. Some concentrations caused 100%mortality,preventing the juveniles from hatching. These two substances are thus efficient andlesstoxicto the environment. The establishment of a protocol for the field use of these substancescanbe an effective way to control exotic snails in infested areas.