Ecological Studies on Common Land Snail Species Infesting Guava and Navel Orange Orchards in Two Regions at Kafr El-Sheikh Governorate

Abstract

Survey and population dynamics of land snail species were carried out in two regions, Abu-Abdalla village, Sedy salm district and Salait village, Quallen distrect at Kafr El- Sheikh Governorate during two successive seasons, 2015 - 2016 & 2016 - 2017 in guava and navel orange orchards. Survey study revealed the existence of three species of land snails, Monacha cantiana, Cochlecilla acuta and Thiba pisana in both of two orchards in two studied regions. Also, survey showed that M. cantiana was predominant in orchards in two studied villages. The population density of these land snail species was studied on soil, stems and leaves of studied trees. The results showed that the highest population was recorded on the soil around trees during spring season. M. cantiana and C. acuta recorded highest population on guava trees, while T. pisana was recorded with highest numbers on navel orange in two studied regions during two seasons. Population dynamics of land snail species were recorded on guava and navel orange from sep. 2015 until Aug. 2017. The results showed that the maximum number of the three land snails M.cantiana , C.acutaand and T. pisan in the two orchards in sedy salm were (495.1) and (143.9) snails / tree during July and June and the lowest number were recorded (12.4) and (19.0) snail / tree during February and March in the first season 2015 /2016.The results also showed that the highest record was (87.9) and (226.0) snails/tree in guava and navel orange orchards during June and May, meanwhile the lowest records (32.7) & (6.0)snails / tree during February and November, respectively in the second season (2016 – 2017).The results also showed that M.cantiana snail recorded the highest numbers on guava and navel orange orchards (260.2) (139.5) snails / tree, during April 2016 and (501.0)(180.4) snails / tree during April in the second season .Estimation of damage caused by M. cantiana land snails to the two orchards were 13, 7 and 10.4 % in orange and guava respectively.