الفهرس 
REVIEW OF LITERATUREOnly 14 pages are availabe for public view
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Abstract
The terrestrial snails are becoming an important pest whereas it attacking different types of crops at different governorates in Egypt. So, the laboratory studies were conducted to study the effect of certain ecological, and biological factors on two tested land snail species, Eobania vermiculata, and Helicella vestalis. Also, the effects of some traditional insecticides, copper sulfate + silver nano-formulation and chitosan biopesticides were investigate.
1. Ecological studies.
1.1. Effect of some ecological, factors on two land snails Eobania vermiculata and Helicella vestalis.
1.1.1. Effect of soil types, soil moisture, and food types on food consumption of the two adult stage Eobania vermiculata and Helicella vestalis.
Three types of soil (peatmous, clay, and sand), soil moisture (40, 60, and 80 %), and two type of food (vegetable leaves and tuber crops) were studied on the food consumption of the two land snail species Eobania vermiculata, and Helicella vestalis using non, and free choice feeding test during seven days of experiment.
The result revealed that the peatmous soil type was the most preferred soil type for two land snail species followed by sand soil, and clay soil. Concerning the soil moisture, the results pointed that the 80 % soil moisture was the best for both tested land snail whereas the food consumption increased with increasing the soil moisture. Also, the results confirmed that the two tested land snails preferred to feed on the kabocha followed by lettuce, cabbage, and red cabbage as avegetable leaves.
Regarding tuber crops, both land snail species preferred to feed on carrots followed by turnip, radish, and potatos. Genarally, both land snails, Eobania vermiculata, and Helicella vestalis preferred to feed on kabocha as vegetable leaves, and carrot as tuber crops at 80 % soil moisture using peatmous soil type. When used as non and free choice feeding test for seven days of consumption.
2. Effect of food consumption of Eobania vermiculata and Helicella vestalis land snails on some biological parameters during certain months.
The effect of the highest favorable food consumption (Kabocha and carrot) for the two land snails, E. vermiculata and H. vestalis on some biological parameters such as (number of eggs, weight of eggs, numberof hatching, depth of eggs and hatchability percentage) for both snails were studied under laboratory conditions.This investigated was carried out under it is preferred type of soil peatmous and soil moisture (80%), during certain months.(according to our previous results part 1).The study also included the effect of the lowest food consumption (Red cabbage and potatoes for the comparison.
Both tested land snail species produced the egg from December to Febrauary, and the eggs production reduced in March. The number of eggs increased when snails fed on kabocha and carrots while it decreased when snails fed on red cabbage and potatos, whereas Eobania vermiculata produced average 82.0± 2 eggs at 4.6± 0.6 cm, with 97 % hatchability in December when fed on kabocha. While Helicella vestalis gave 54.0± 3.5 eggs at 4.7± 0.6 cm with 99 % hatchability when fed on kabocha in November. When Eobania vermiculata fed on red cabbage, it produced the highest number of eggs 60.0± 3.5 at 4.7± 0.6 cm with 86 % hatchability in December, Also, Helicella vestalis gave the highest egg production in December which produced 48.7± 6.6 at 3.8± 0.9 with 83 % hatchability. In case of snails fed on carrots, and potatos, Eobania vermiculata gave the highest number of eggs in December and Febrauary, respectively. Whereas it produced 83.0± 5.1 and 55.7± 3.4 eggs, consecutively. While Helicella vestalis produced the highest number of eggs in January and December which gave 63.3±2.1 and 47.7± 2.3 eggs, respectively after feeding on carrots, and potatos, consecutively.
3.Toxicity of certain chemical compounds against Eobania vermiculata and Helicella vestalis under laboratory conditions.
The laboratory studies were conducted to evaluate the molluscicidal activity of two conventional chemical pesticides, inorganic compound as nano-formulation and biopesticide compound against two tested land snail species, Eobania vermiculata and Helicella vestalis using leaves dipping technique. The snails were feed on treated leaves for seven days.
3.1. Toxicity of the tested pesticides.
Results showed that methomyl was more toxic than lambada for Eobania vermiculata in all stages whereas the LC50 were (0.33 & 0.47), (0.37 & 0.61), (0.49 & 0.70), (0.70 & 0.82), and (0.75 & 0.99 %) after seven days of treatment for two, four, six, eight weeks, and adult stages, respectively. Also, Helicella vestalis was more susceptible to methomyl than lambada for all stages whereas LC50 were (0.25 & 0.30), (0.26 & 0.33), (0.38 & 0.49), (0.52 & 0.65), and (0.65 & 0.72 %), respectively for the same tested stages.
3.2. Toxicity of inorganic compound as nano-formulation and biopesticide compounds.
Results pointed that copper sulfate + silver nano-formulation compound was more toxic than chitosan biopesticide for Eobania vermiculata for all stage. The LC50 were (0.61 & 0.69), (0.82 & 0.96), (0.95 & 1.18), (1.00 & 1.21), and (1.04 & 1.32 %), for two, four, six, eight, weeks and adult stages, respectively. The same results occurred with Helicella vestalis whereas LC50 values were (0.40 & 0.46), (0.49 & 0.61), (0.64 & 0.78), (0.80 & 0.99), and (0.70 & 0.91 %) for the same tested stages of snail after seven days of treatment, consecutively.
Moreover, the results revealed that traditional pesticides were more toxic than inorganic and biopesticide compounds whereas it can be arranged them against both tested land snail species in descending order as follow, Methomyl > Lambada > copper sulfate + silver (nano-formulation) > chitosan.
Farthmore the results revealed that Eobania vermiculata was more tolerant for all compounds than Helicella vestalis.