ABSTRACT
Objective To investigate the effectiveness and cost of 50% and 80% wettable powder of niclosamide ethanolamine salt (NESWP) and 26% metaldehyde and niclosamide suspension concentrate (MNSC) in hilly schistosomiasis-endemic regions, so as to provide insights into the selection of chemical molluscicides in hilly regions. Methods In September 2020, a wasteland in Guanshanqiao Village, Yanrui Township, Yushan County of Jiangxi Province was selected as the experimental region, which was sectioned into five blocks and defined as four experimental groups (A1, A2, B, C) and a blank control group (D). 80% NESWP were given at doses of 1 g/m2 and 1.5 g/m2 in groups A1 and A2 using the spraying method, 50% NESWP was given at a dose of 2 g/m2 in Group B using the spraying method, and 26% MNSC was at a dose of 4 g/m2 in Group C using the spraying method, while no chemical treatment was given in Group D. Snail survey was performed using a systematic sampling method before chemical treatment and 1, 3, 7 d and 15 d post-treatment to examine the molluscicidal effect, and all molluscicidal costs were estimated to calculate the cost of chemical treatment per 1 m2 and the cost of the reduction in the mean density of living snails per 1%. Results The highest mortality of snails was 78.95% and the lowest density of living snails was 0.2388 snails/0.1 m2 in the experimental groups within 7 d of chemical treatment, and the highest mortality of snails was 94.74% and the lowest density of living snails was 0.058 0 snails/0.1 m2 7 d post-treatment. There were no significant differences in the snail mortality among the A1, A2, B and C groups 1 (χ2 = 2.250, P > 0.05), 3 (χ2 = 1.779, P > 0.05) or 15 d post-treatment (χ2 = 2.286, P > 0.05), while a significant difference was detected in the snail mortality among the four groups 7 d post-treatment (χ2 = 7.990, P = 0.046). In addition, there were no significant differences in the snail mortality between A1 and A2 groups 1 (χ2 = 0.724, P > 0.05), 3 (χ2 = 0.584, P > 0.05), 7 (χ2 = 0.400, P > 0.05) or 15 d post-treatment (χ2 = 0.251, P > 0.05). The costs of chemical treatment per 1 m2 were 0.58, 0.60, 0.64 Yuan and 0.73 Yuan in groups A1, A2, B and C, and the costs of the mean density of living snail per 1% reduction were 19.29, 20.44, 21.68 Yuan and 23.53 Yuan in groups A1, A2, B and C, respectively. Conclusion 80% NESWP shows a high molluscicidal efficacy and low cost in hilly schistosomiasis-endemic regions.
ABSTRACT
Objective To compare the effectiveness of snail control between immersion of molluscicides through tide diversion and mollusciciding by spraying in marshland areas. Methods Immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion and spraying 26% suspension concentrate of metaldehyde and niclosamide alone were employed for snail control in two neighboring snail-breeding marshlands, and snails were surveyed before and after mollusciciding. The mortality of snails and the density of living snails were estimated. Results The density of living snails reduced by 72.19% and 100.00% 1 and 2 years after immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion, and 5.93% and 18.15% 1 and 2 years after spraying 26% suspension concentrate of metaldehyde and niclosamide alone. Conclusion Immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion is significantly superior to spraying 26% suspension concentrate of metaldehyde and niclosamide along for snail control, and implementation of immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion for more than 2 successive years may achieve a higher snail control efficiency.
ABSTRACT
Objective To compare the effectiveness of snail control between immersion of molluscicides through tide diversion and mollusciciding by spraying in marshland areas. Methods Immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion and spraying 26% suspension concentrate of metaldehyde and niclosamide alone were employed for snail control in two neighboring snail-breeding marshlands, and snails were surveyed before and after mollusciciding. The mortality of snails and the density of living snails were estimated. Results The density of living snails reduced by 72.19% and 100.00% 1 and 2 years after immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion, and 5.93% and 18.15% 1 and 2 years after spraying 26% suspension concentrate of metaldehyde and niclosamide alone. Conclusion Immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion is significantly superior to spraying 26% suspension concentrate of metaldehyde and niclosamide along for snail control, and implementation of immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion for more than 2 successive years may achieve a higher snail control efficiency.
ABSTRACT
This research reports the terrestrial slug Meghimatium pictum (Stoliczka, 1873) (Stylommathophora: Philomycidae) as an agricultural pest for the first time in Southern Brazil vineyards. The species was found in densities exceeding 20 slugs.m-2 in Vitis labrusca L. vineyards at six municipalities of the Southern Brazil's viticulture region. It causes damage a loss by leaving residual mucus on grapes and by consuming grapes already perforated by other organisms, such as insects or birds, or mechanically damaged by in situ compression. The effectiveness of iron phosphate and metaldehyde baits on M. pictum was evaluated in laboratory experiments. Iron phosphate bait was more effective in controlling M. pictum (70%) than metaldehyde bait (15%).
O presente trabalho relata pela primeira vez a lesma terrestre Meghimatium pictum (Stoliczka, 1873) (Stylommathophora: Philomycidae) como uma praga agrícola causando danos em vinhedos no Sul do Brasil. Esta espécie foi encontrada em densidades superiores a 20 lesmas.m-2 danificando uvas da espécie Vitis labrusca L. em seis municípios da região vitícola do Sul do Brasil. O impacto econômico causado por M. pictum está associado ao movimento dos espécimes no dossel da videira e nas uvas, provocando a contaminação residual por muco e o consumo de uvas já perfuradas por outros organismos, tais como insetos ou aves, ou mecanicamente danificadas pela compressão in situ. A eficácia das iscas a base de fosfato de ferro e metaldeído sobre M. pictum também foi avaliada em condições de laboratório. A isca a base de fosfato de ferro foi mais eficiente no controle de M. pictum (70%) do que a isca a base de metaldeído (15%).
ABSTRACT
Objective To compare the molluscicidal effects between“Luo-wei”(TDS),a plant molluscicide in 4 percent, and metaldehyde and niclosamide(MNSC)in the field. Methods A natural ecological environment with Oncomelania hupensis was selected as the test area,the test concentrations of TDS and MNSC were 2.5 g/m3 and 2 ml/m3 respectively by the immersion method;the test doses of TDS and MNSC were 3 g/m2 and 2 ml/m2 respectively by the spray method;the doses of WPN in a control group were 2 g/m3 and 2 g/m2 respectively by the two methods above-mentioned. The molluscicidal effects between TDS and MNSC were compared by using the synchronous design method and parallel comparative method. Results In the TDS group,the death rate of snails was 90.70%by immersion for 24 hours,reached to 81.40%after spraying for 7 days,and there were no significant differences among the observation time points in molluscicidal effects(P>0.05). One day after the spraying,the death rate of snails was less in the TDS group compared with that in the MSCN group(P0.05). In the MSCN group,the death rate of snails was 99.17%by immersion for 24 hours,reached to 66.07% by spraying for 1 day. In the WPS group,the death rate of snails was 97.15% by immersion for 24 hours,reached to 71.43%after spraying for 1 day,and there were no significant differences(both P>0.05). Conclusion TDS has a good molluscicidal activity and stable efficacy,and the molluscicidal effect of TDS is similar to that of MSCN in the filed, but the molluscicidal sensitivity of TDS is lower than that of MSCN.
ABSTRACT
Studies were done to see the effects of five toxic baits based on metaldehyde and/or carbaryl on the taxonomic composition of soil meso and macrofauna, and determined the density of beneficial organisms in soybean under no tillage. Six treatments were tested and soil monoliths were taken before application and at 45 and 75 days after application (DAA). Before application, 1601 individuals were recorded, belonging 1086 to mesofauna and 515 to macrofauna. In soil mesofauna such as Annelida: Enchytraeidae (44%), Nematoda (33%) and Arthropoda (23%) were found. In the macrofauna Arthropoda 93% and Annelida: Oligochaeta, Megadrilli 7% were observed. No differences were observed among the treatments (p>0.05) in the total mesofauna density, at 45 and 75 DAA. The density of enchytraeids, mites, collembolans and symphylids showed no differences at 45 and 75 DAA (p>0.05). The total macrofauna density showed differences (p<0.05) at 45 and 75 DAA. The highest density was obtained with 4 kg ha-1 MataBibos Acay at 45 and 75 DAA. Earthworm and diplopod densities at 45 and 75 DAA showed no differences (p>0.05). The diversity of meso and macrofauna was not affected at 45 and 75 DAA. Bait application did not affect either the abundance or the diversity of soil beneficial invertebrates.