الفهرس 
Ecological studiesOnly 14 pages are availabe for public view
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Abstract
Terrestrial snail and slug species had became one of the
dangerous pests especially in last few years because they cause
considerable damage of different economic crops not only in Egypt
but also in all over the world.
1. Ecological studies:
The ecological studies were carried out in Minufiya
Governorate on field crops (Egyptian clover, wheat and horse bean),
vegetable crops (Lettuce, Cabbage and potatoes), fruit trees (Navel
orange, Grape and Pear) and ornamental plants (sansevieria, duranta
and acalypha).
1.1. Survey of land snail and slug species:
Survey and distribution of land snail and slug species infesting
the various host plants in Minufiya Governorate was conducted
through the period study from September to August during two
successive years 2003/2004 and 2004/2005. Data revealed that:
(1) Presence of five species of land snails, Monacha cartusiana
(Muller), Eobania vermiculata (Muller), Helicella vestalis
(Pfeiffer), Oxychillus alliavus (Pfeiffer) and Cochlicella acuta
(Muller) and one slug, Deroceras reticulatum (Muller).
(2) Species of land snails and slugs were collected from some field
crops, vegetable, fruit trees and ornamental plants at twenty five localities belonging to five districts; Shibin El-Kom, Tala,
Ashmoun, Quessna and El-Shohadaa, Minufiya Governorate.
Total numbers and relative density of each species at five
districts of Minufiya Governorate were arranged as follows: M.
cartusiana (14448, 71.89%), E. vermiculata (3519, 17.51%), H.
vestalis (752, 3.74%), O. alliavus (686, 3.41%), D. reticulatum
slug (428, 2.13%) and C. acuta (265, 1.32%), respectively.
(3) Relative percentages of different snails and slugs of each district
were arranged as followed; Quessna (22.47%), El-Shohadaa
(21.7%), Shibin El-Kom (19.54%), Ashmoun (19.52%) and Tala
( 16.76%), respectively. The obtained results showed that M.
cartusiana land snail was the predominant species with high
population density on some different economic crops in
examined localities, followed by E. vermiculata land snail on
ornamental plants and some other host plants. While, H. vestalis,
O. alliavus and C. acuta were appeared with low population
densities in some examined localities on fruit trees and other
hosts.
(4) Distribution of population density for different land snail and
slug species showed that, field crops was the highest infested
group with average 2243 followed by vegetable crops with
1621.3, fruit trees with 1539.7 and ornamental plant with 1293.
It noticed that, field and vegetable groups were the resource of infestation by the glassy clover snail M. cartusiana. While,
ornamental plants were the main resource of infestation by the
brown garden snail, E. vermiculata.
1.2. The horizontal distribution of different snails carried out on
some host plants at Minufiya Governorate. Obtained data cleared
that, populations of land snails were found with high numbers
beside edges of different fields according to geographical
direction. Average of various land snail species per sample were
arranged as follows; eastern north 18.9 > center 13.7 < western
south 17.4.
1.3. Population dynamics of land snails infesting ornamental
plants and fruit trees in Minufiya governorate :
Seasonal population dynamics of land snails were conducted
during two successive years 2003/2004 and 2004/2005.
1.3.1 Population dynamics of land snails infesting
ornamental plants at Kafr El- Sokaria locality ,Tala destrict
,Minufiya governorate:
Seasonal population dynamics of E.vermiculata land Snail was
carried out on Sansevieria , Acalypha and Duranta plants one
nursery of each ornamental plant was selected .10 plants were
randomly chosen and examined every month in quadrate of samples
during the period of study. The results cleared that, the highest mean of population density on Sansevieria .Acalypha and Duranta was
(35/5and37.4),(22.5and24.0)and (28.3and29.4)individuals /sample
during February of 2004 and 2005.while , the lowest mean was
(15.5and 18.7),(11.4and13.0)and (13.5and 15.4)individuals / sample
during September of 2003 and 2004.
1.3.2. Population dynamics of land snails infesting fruit trees at Begarim
locality, Quessna district, Minufiya governorate:
Seasonal population dynamics of Monacha cartusiana land
snail were carried out on Navel orange, Grape and Pear trees, one
feddan of each fruit variety was selected, ten trees were randomly
chosen and examined every month in same time in quadrate sample
during the period of study. The obtained results showed that ,the
highest mean of population density N. orange ,Pear and Grape trees
was (36.7and38.1) , (31.9and32.7)and (28.7and30.1)individuals
/sample during April and March of 2004 and 2005.While ,the lowest
mean was (10.5and 11.2),(8.5 and9.5)and (8.0and 9.3) individuals
/sample during August of 2004 and 2005.
1.4. Estimation of certain food stuff consumption by common
land snail species under laboratory conditions:
Estimation of food consumption by M. cartusiana and E.
vermiculata was estimated by weighing the daily consumed leaves of lettuce, pear, cabbage, E. clover, grape and N. orange of during the
period of experiment.
The results illustrated that the daily feeding damage caused by
ten adults of M. cartusiana were from 0.062 to 0.497 gm of leaves ,
and the highest values were found with lettuce 0.497 gm., while, the
lowest values were 0.062 gm with pear leaves. On the other hand,
feeding damage caused by ten adults of E. vermiculata were from
0.071 to 0.525 gm during 24 hrs. The highest amount of food were
0.525 gm with lettuce, while the lowest amount were 0.071 gm with
pear.
2. Control studies of common land snails:
In these studies, three pesticides, sea salt and hand collection
were tested against the glassy clover snail M. cartusiana, brown
garden snail E. vermiculata and small sand snail H. vestalis.
2.1. Evaluation of some pesticides against M. cartusiana and
E. vermiculata under laboratory conditions:
Three pesticides, Abamectin 1.8% EC., Selecron 72 EC. And
Neomyl 20% WP were tested as a poisonous baits with different
concentration. Neomyl compound recorded the highest
molluscicidal , followed by Selecron and Bermectin, LC50 values of
Neomyl, Bermectin and Selecron were 1.59, 1.75 and 2.42%, espectively for M. cartusiana. While, it were 0.73, 1.95 and 2.22%
for E. vermiculata, respectively.
2.2. Evaluation of hand collection method as mechanical
control:
This study was conducted in a citrus orchard infested with
high numbers of M. cartusiana and low numbers of H. vestalis at
Sahel El-Gawaber, El-Shohadaa district, Minufiya Governorate.
Quarter of feddan was selected and ten orange trees were
randomly chosen to carry out this study. Results showed that population
density of M. cartusiana and H. vestalis were decreased with percent of
61.5 and 54.9%, respectively during the period from 15 June to 15 July.
2.3. Influence of sea salt in reducing numbers of certain land
snail species:
This trail carried out in a nursery cultivated with Duranta plant
infested with moderate numbers of E. vermiculata and low numbers
of M. cartusiana land snail, five Duranta plants were randomly
chosen for the salt treatment and other five plants served as control.
The results cleared that population density of E. vermiculata and M.
cartusiana land snail were reduced with percent of 78.74 and
78.45%, respectively, after 20 days of application .