Abstract

The effect of seasonality on abundance of the African weaver ant (AWA) was determined in the cashew fields at Bagamoyo and Kibaha districts, Coast Region of Tanzania. Twenty cashew trees colonized by AWA were randomly selected per site and its abundance was monitored during cashew on-seasons and off-seasons in 2011 and 2012. Results showed that abundance of AWA, which was expressed as mean numbers of leaf nests per tree and colonization of trails on main branches, varied significantly between cashew on-seasons and off-seasons. The mean numbers of leaf nests per tree during cashew on-season and off-season varied between 8.3 and 5.0 and between 7.5 and 4.8 at Bagamoyo and Kibaha, respectively, in 2011. Similarly, in 2012 it varied between 9.5 and 5.6 and between 8.6 and 5.3 at Bagamoyo and Kibaha, respectively. The mean percentage AWA colonization of trails during cashew on-seasons and off-seasons varied between 72.5 and 54.2% and between 73.3 and 50.9% in 2011and 2012; it also varied between 74.3 and 57.0% and between 72.6 and 54.9% at Bagamoyo and Kibaha, respectively. The abundance of AWA in the two parameters studied varies significantly between the two seasons. This suggests the use of conservation strategies during the off-seasons to supplement diets of AWA.

Key words: Colonization, Oecophyllalonginoda, off-season, on-season, trail.