The clover land snail, Monacha obstructs (Ferussae), is a destruc­tive pest to field vegetable and ornamental crops as well as some fruit orchards. Monitoring studies were carried out in an apple orchard inter-planted with Egyptian clover at El-Saff, Giza Governorate, during two successive years from October, 1997 to September, 1999. M. obstructs was found on apple trees all the year round with peaks during June/July to September, 1998 and 1999. The maximum abundance took place dur­ing summer (54%) followed by spring (26%), while they were 15 % and 5 % during autumn and winter, respectively M. obstructs attacked the Egyptian clover fields from October and increased during the following months to reach maximum at the end of the season in May of the next year. The two highest seasonal activities were achieved during winter (46%) and spring (43%) seasons. Accordingly, it is preferred not to interplant apple orchards with Egyptian clover since the later is a preferable host to M. obstructs.