Correlation between ovicidal effectiveness and egg-membrane penetration determined by chromatography in two modes of biomphalaria Alexandrina eggs exposure to certain plant and chemical molluscicides

The weak ovicidal effect of the plants having molluscicidal activity is a criterion against their field application in controlling the medically important snails. Chemical molluscicides are potent against snails and their eggs. This work is a trail to use bayluscide and CuSO4 [chemical molluscicides] in sub lethal concentrations to improve the ovicidal effect of Anagallis arvensis and Calendula micrantha plants against the eggs of Biomphalaria alexandrina snails through two modes of eggs exposure. The first was the pre-exposure of snail's eggs to sub lethal concentrations of chemical molluscicides followed by plant exposure and this improve the effect of plants against the snail's eggs with a synergistic ratio ranged from 1.5 to 4.49. While the second mode of exposure is to evaluate the toxicity of mixtures of chemical molluscicides and plants against snail's eggs. It was noticed that this moda resulted in 100% mortality when eggs exposed to mixture of LC15 of C. micrantha or LC25 of A. arvensis with sublethal concentrations of the molluscicides bayluscide or copper sulphate. TLC reveals that the number of the penetrated plant compounds increased in all copper sulphate treatments and in pre-exposure of C. micrantha by bayluscide while the same number of plant compounds were penetrated in the rest of bayluscide treatments as in the cese of the plant alone. So, the increase in plant potency was through chemicals that affect the eggs' membrane to be permeable for more active ingredients [more in number or concentration or both of them] of the tested plants to become in contact with the target embryos

Impact of certain plants and synthetic molluscicides on some fresh water snails and fish

The LC50 [78, 85 ppm] and LC90 [88, 135 ppm] of Anagalis arvensis and calendula micrantha respectively against Biomphalaria alexandrina were higher than those of the non-target snails, Physa acuta, Planorbis planorbis, Helisorna duryi and Melanoides tuberculata. In contrast, the LC50 of Niclosamide [0.11 ppm] and Copper sulphate [CuSo4] [0.42 ppm] against B. alexandrma were lower than those of the non-target snails. The mortalities percentage among non-target snails ranged between 0.0 and 20% when sublethal concentrations of CuSo4 against B. alexandrina mixed with those of C. micrantha and between 0.0 and 40% when mixed with A. arvensis. Mortalities ranged between 0.0 and 50% when Niclosamide was mixed with each of A. arvensis and C. micrantha. A. arvensis induced 100% mortality on Oreochromis niloticus after 48 hrs exposure and after 24 hrs for Gambusia affinis. C. micrantha was non-toxic to the fish. The survival rate of O. niloticus and G. affinis after 48 hrs exposure to 0.11 ppm of Niclosamide were 83.3% and 100% respectively. These rates were 91.7% and 93.3% respectively when each of the two fish species was exposed to 0.42 ppm of CuSo4. Mixture of sub-lethal concentrations of A. arvensis against B. alexandrina and those of Niclosamide or CuSo4 at ratios 10:40 and 25:25 induced 66.6% mortalities on O. niloticus and 83.3% at 40: 10. These mixtures caused 100% mortalities on G. affinis at all ratios. A. arvensis CuSo4 mixtures at 10:40 induced 83.3% and 40% mortalities on O. niloticus and G. affinis respectively and 100% mortalities on both fish species at ratios 25:25 and 40:10. A mixture of sub-lethal concentrations of C. micrantha against B. alexandrina and of Niclosamide or CuSo4 caused mortalities of O. niloticus between 0.0 and 33.3% and between 5% and 35% of G. affinis. The residue of Cu in O. niloticus were 4.69, 19.06 and 25.37 mg/ l kgm fish after 24, 48 and 72 hrs exposure to LC0 of CuSO4 against B. alexandrina respectively

Reproductive risk assessment in wistar albino rats exposed to ametryne and niclosamids

This investigation was designed to assess the reproductive risk of using ametryne and/or niclosamide in the environment. Female and male Wistar albino rats received 1/50 KD50 of ametryne and niclosamide either individually or in combination. Females were treated for 2 weeks prior to mating, throughout mating and pregnancy, to day 21 of lactation, while males were treated for 13 weeks prior to mating. Mating was performed between treated/un-treated females and treated/un-treated males. The results showed neither mortality, clinical nor gross adverse effects in the treated animals. In females treated groups, either ametryne or niclosamide treatment significantly reduced mating and fertility indices. Percentage of post-implantation loss increased under the influence of the combined treatment. In male treated groups, mating, fertility and gestation indices were significantly reduced in the niclosamide-treated group while% treated groups. Number of pups at birth and% of pups/litter that post- implantation loss was survived until weaning were significantly decreased after niclosamide treatment while it was increased after combined treatment. Nevertheless, in female and male treated groups, mating, fertility and gestation indices were significantly decreased after niclosamide or combination treatment

Effect of copper sulphate and bayluscide on fresh water snails of Sharkia governorate

In this study, the effect of two molluscicides [copper sulphate and bayluscide], was tested against fresh water snails Bulinus truncus, Lymnaea cailliaudi, Biomphalaria alexandrina, Physa acute, Melania tuberculate, Cleoptra sp., Viviparus unicolor, Lanistes bolteni at different localities in Sharqia Governorate. The lethal effect of both molluscicides increased with increasing its concentration. Bayluscide was more efficient and the non operculated snails were more susceptible