الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 155 |  |  |
| | | from | 155 | | |
Abstract
Terrestrial snails are considered serious molluscan dangerous pests to several economic crops,vegetables, fruits, ornamental plants and field crops, and effect of this dangerous to occur direct or indirect method, due to the fact that to feeding after hatching on capillary of roots under surface of soil then feeding on fresh leafs and fruits causing serious dangerous. In addition to leave their slim material during their moving on plants especially fodder crops i.e.: clover, to make this animals refused feeding on this plants. They are considered carrier to fungous and viruses diseases of plant to other during their moving, and therefore increased rate of damage and decreased commercial and marketing importance, thus decrease economics proceeds for these crops. Contribution in trial the control or limit of serious this species of pests which increased this serious especially in the last time and to attach important to the present study to focusing on study of some points at following:
1. Ecological studies:
1.1. Survey studies of terrestrial snails:
Survey was carried out on terrestrial snails infesting different crops during 2018-2019 in Nobaria city, Beheira Governorate and Mansouria Village at Giza Governorate. Results revealed that, two terrestrial snail species E. vermiculata and T. pisana were recorded on different crops at Nobaria destrict, Beheira Governorate. It was abvious that heavy infestation of E. vermiculata and T. pisana were recorded on fruit trees. While light infestation of the two species of land snails were recorded on potato, onion crops.
At Mansoria Village, Giza Governorate showed two terrestrial snail species M. obstructa and E. vermiculata were recorded on different crops. The heavy infestation of M. obstructa was recorded on cucumber and Egyption clover. Also, the light infestation was recorded on navel orange, mango, olive, grape, pear, onion, Mint, basil and palm tree. On the other hand, E. vermiculata was recorded heavy infestation on fruit trees, orange, mango, grape and pear. While the light infestation was recorded on egg plant, mint, basil and punica granatum.
1.1. Seasonal population dynamics of some terrestrial snails on fruit trees at Beheira and Giza Governorate.
Survey studies revealed that, E. vermiculata and T. pisana snails with a relatively high infestation on fruit trees followed by M. obstructa was the lowest infestation. Therefore, population dynamics of such snails were studied on orange, apple and mango trees at Nobaria destrict, Beheira Governorate and Mansouria, Giza Governorate during two seasons (2018-2019) and (2019-2020). Also, relation to temperature and relative humidity was studied.
1.2.1. Seasonal dynamics of E. vermiculata on fruit tree at Nobaria,
Beheira Governorat.
Results revealed that, the highest population density of E. vermiculata was detected in March (2018-2019) and (2019-2020) on orange trees 107.40 and 92.00 snails/10 trees followed by apple and mango trees 98.50 and 85.30, 78.10 and 50.10 snail /10 trees respectively. The correlations between some climatic factors, temperature and relative humidity showed variable effect on population density of E. vermiculata on orange, apple and mango. Temperature showed significant effect on number of E. vermiculata during season (2019-2020) on apple and Mango. Relative humidity showed non- significant effect on number of E. vermiculata during two successive seasons.
1.2.2. Seasonal population dynamics of T. pisana on fruit trees at Nobaria, Beheira Governorate.
Data indicated that, the highest population density of T. pisana was recorded in Spring season especially in March (2018-2019) on orange trees 61.10 snails 10 trees followed by mango and apple trees 50.20 and 46.70 snails 10 trees, respectively. While in March (2019-2020) was recorded the highest population density on mango trees 62.80 snails 10 trees followed by apple and orange 55.10 and 45.20 snails 10 trees, respectively. The correlations between some climatic factors, Temperature showed significant effect on number of T. pisana in orange and apple but high significant in mango during (2018-2019) while, relative humidity showed significant effect during (2019-2020).
1.2.3. Seasonal population dynamics of M. obstructa on fruit trees at Mansoria Village, Giza Governorate.
Results revealed that, the highest population density of M. obstructa was detected in March (2018-2019) on orange trees followed by apple and mango trees 28.10, 27.30 and 26.70 snails / 10 trees, respectively. While during season (2019-2020) the highest population density of M. obstructa was recorded on mango trees followed by orange and apple 32.70, 27.40 and 21.90 snail / 10 trees, respectively. The correlations between some climatic factors, Temperature showed significant effect of M. obstructa in orange but non-significant in Apple and high significant in mango trees during season (2018-2019). While during season (2019-2020) temperature showed high significant effect of M. obstructa in orange. Relative humidity showed in orange significant effect during season (2019-2020).
1.2.4. Seasonal population dynamics of E. vermiculata on fruit trees at Mansoria Village, Giza Governorate.
Data showed that, the highest population density of E. vermiculata was recorded in March (2018-2019) on orange trees followed by apple and mango trees 62.50 and 58.20, 50.20 snail / 10 trees, respectively. While during season (2019-2020) the highest population density of E. vermiculata was recorded on orange trees 70.40 snail/ 10 trees, followed by mango and apple 60.70 and 60.10 snails 10 trees, respectevily according to temperature and relative humidity degrees. Generally, values of population density gradually increased in the end of winter to reach the maximum values during spring. The highest population densities of adult in March during the two successive seasons (2018-2019) and (2019-2020), respectively. The correlations between some climatic factors, temperature showed significant effect on numbers of. E. vermiculata during (2018/2019). Also, was recorded highly significant effect on the population dynamic of E. vermiculata in Apple trees, while temperature during (2019-2020) showed significant effect on the population dynamic of E. vermiculata in orange and apple, also was recorded highly significant in mango trees during (2019-2020).
2. Estimation of damage caused by E. vermiculata snail to some host plants:
Damage induced by E. vermiculata to different plant crops showed the highest damage was recorded on Sunflower leaves followed by cabbage and tomato with % damage 37.13, 28.80 and 15.28%, while in ornamental plants the lowest damage percentage was recorded on Potos leaves 8.22 % comparing with armenian and alternanthera 16.63 and 13.69 %. Also, field crops were recorded damage percentage by E. vermiculata 19.05 % on Pea nuts. While fruits (Orange leaves) was recordrd 14.01 % damage percentage.
3. Food consumption under laboratory conditions.
Effect of food type on food consumption of E. vermiculata were studied under laboratory conditions. On vegetable crops, daily food consumption was reached to its peak when snails fed on cabbage leaves with ageneral mean 4.64±0.10 gm.day-1, followed by lettuce leaves, food consumption was recorded 1.79 ±0.20 gm day-1. While the lowest values of food consumption were recorded when snails fed on cauliflower and sweet potato with ageneral mean 0.99 ±0.08 and 0.34±0.04 gm day-1, respectevily.
On field crops, data revealed that, feeding on broad bean recorded the highest food consumption during the five days with ageneral mean 0.85 ± 0.09 gm/ day-1, followed by sunflower food consumption was recorded 0.39 ± 0.01 gm/ day-1. While the lowest food consumption was recorded when snail’s feed on wheat and Egyptian clover with a general average 0.37 ± 0.06 and 0.37 ± 0.01 gm day-1 respectively and no significant differences between them were recorded.
Concerning to fruit leaves, aslightly food consumption of E. vermiculata was recorded on guava with ageneral mean 0.46 ± 0.03 gm. day-1 comparing with orange and mango was recorded 0.37 ± 0.02 and 0.37 ± 0.05 gm. day-1 respectively. The lowest value of food consumption was recorded on avocado with ageneral mean 0.21 ± 0.03 gm day-1.
On ornamental plants, the highest food consumption was recorded on paper mint and basil with a general mean 0.54 ± 0.05 and 0.53 ± 0.08 gm. day-1 respectevily. While the lowest food consumption recorded on geranium leaves and castor oil with a general average 0.29 ± 0.03 and 0.31 ± 0.04 gm day-1 respectively.
4. Toxicity studies the tested pesticides.
4.1. Toxicity of certain compounds against E. vermiculata snail under laboratory and field condition.
Three groups of tested compounds, plant extract (Techno-oil, Berna star), natural compound (Repcar, Top-nine and Nema ultra chem) and chemical pestcides (Methomyl and lambda-cyhalothrin) were evaluated as poison baits against E. vermiculata snail under laboratory and field conditions.
4.1.1. Toxicity of tested compounds against the adult stages of Eobania vermiculata under laboratory condition.
Results showed that, the susceptibility of the land snail Eobania vermiculata to the tested compounds. Methomyl (Goldben) was the most effective compound with Toxicity Index 100% followed by Lambda power, Repcar, Top-nine, Techno oil, Berna Star and Nema Ultra Chem with LC50 (1.90, 4.20, 11.10, 16.10, 17.30, 28.50 and 44.40%), respectively. These results mean that synthetic compounds were more toxic than natural compounds or plant extract.
4.1.2. Biochemical impacts on Eobania vermiculata:
4.1. 2.1. Effect of plant extract on some biochemical parameters in E. vermiculata.
The results with (plant extract) showed that, Techno oil has no significant effect on total protein content, while it increases ALP activity with difference percentage 6.9% (according to control). The adverse effect was observed in case of ACP whereas the Techno oil caused significant decreasing from in treatment with -25.3 difference terrestrial snail E. vermiculata percentages (comparing with control). Regarding Berna Star, it decreased the total protein content with -61.1 difference percent (comparing with control).
4.1.2.2. Effect of natural compounds on some biochemical parameters in E. vermiculata.
The results revealed that Top-nine as natural compound caused significant increasing with recorded to 38.8% in total protein content comparing with control and the same results occurred with ALP and ACP, whereas, it caused significant increasing in the activity of enzymes with difference percent 5.3 and 4.2%, respectively comparing with control. The opposite effect happened in Nema Ultra Chem, which caused significant decrease in the total protein content, ALP and ACP activity, where, it decreases with difference percent -47.2, -4.0 and -6.7%, respectively comparing with control.
Regarding to Repcare, it caused a fluctuated effect on thesome parameters that it caused significant increase in total protein that enhanced from 18 g dLG1 in control to 3.1 g dLG1 in treatment, however it decreased the activity of ALP enzyme from 2727.0 µ LG1 in control to 2581.6 µ LG1 in treatment, while, it observed that the Repcar compound caused enhancing in activity of ACP enzyme with 33.9% comparing with control.
4.1. 2.3. Effect of tested Synthetic formulations pesticides on some biochemical parameters in E. vermiculata.
The results indicated that Goldben 90% (Sp) compound caused significant increased on total protein content and ALP activity comparing with control with 316.7 and 34.0% difference, individually, while it affected significant decreased on ACP with -99.6% differences comparing with control treatment.
Lambda power 5%, cased significant increasing on total protein with 494.4% difference with control, while, it caused decreasing on ALP and ACP with -6 and -167.1% difference with control, consecutively. This means that two tested compounds had a strong effect on the tested parameters.
5.Toxicity of the tested compounds against the adult terrestrial snail of Eobania vermiculata under field conditions.
Results revealed that, techno oil is more effective than berna star (21.51 and 7.60 % mortality) respectively. when used concentration 32, 35 and 25% for top-nine, repcar and nema Ultra chem, Results revealed that (16.94, 24.18 and 13.55 % mortality) respectively. while used concentration 3 and 7.5 % for goldben 90% Sp and lambda power 5%. Results revealed that goldben 90% Sp exhibited the highest initial kill were gave 78.24 % mortality percentage follow by lambda power 5% give 55.6% mortality. Regarding the residual effect of previous mentioned compounds showed that goldben 90% Sp exhibited the highest reduction percentage 78.24 % follow by all compounds while berna star give low effective reduction percentage during the experiment period.