Why is the Red Spider Mite (Tetranychus evansi) a threat to Dry Season Tomato Growing in Tabora, Tanzania

Dry season tomato (Lycopersicon esculentum L.) growing is an important economic activity in semi-arid Tabora region of western Tanzania. However, red spider mite (Tetranychus evansi Baker & Prichard) has emerged as a threat to dry season tomato growing in smallholders’ fields. A study was carried out in Tabora,Tanzania in order to discover factors leading to increased red spider mite infestation in tomato fields. A survey of dry season tomato growing fields was carried out in June through September in the districts of Uyui, Urambo and Tabora Municipality, for a period of three years from 2012 through 2014. Discussions with farmers and collection of pesticide containers left in the fields helped us to understand the existing gap for establishment of an effective strategy for red spider mite control. It was found that farmers lack a strong agricultural extension support to effect the integration of basic technical guidelines of integrated pest management and safe procedures ofpesticide handling practiced in intensive outdoor tomato growing system. The results show that there was a high significant difference (P<0.001) in the severity of attack by red tomato spider mites among tomato fields. Red spider mites attack a wide range of alternative host plants including weeds and field crops. Profecron 720 gm/litreinsecticide was used by most farmers (55.5%). Red spide mites significantly (P<0.001) attached tomato leaves than stems and dry flowers. They caused up to 100% crop loss in tomato. Use of inefective chemicals, poor field sanitation, dry climate and lack of agricultural extension support in agronomy and pesticide use wereidentified as factors contributing to farmers’ inability to control red spider mites in the study area. Waging a war against red spider mites is urgently needed by stakeholders engaged in horticulture