Behavioral Responses of tuta absoluta to a Wild and Cultivated Tomato Plants and Characterization of the Mediating Semiochemical blends

Tomato is rated the second most important horticultural crop after potato in most parts of the world. However, its cultivation is threatened by infestations of Tuta absoluta (Lepidoptera: Gelechiidae). The pest originated from South America and is now invading fields and greenhouse production sites in the world. Tuta absoluta was first officially reported in Kenya in March 2014 at Isiolo and has spread to all parts where tomato is grown. The pest has been nicknamed tomato ‗Al–shabaab‘ as it leaves unimaginable damage of the crop after infestations. Chemical methods used to control the pest have led to high levels of residues, hence risking consumers, harming the ecology and the environment. The present study was based on field observations that a wild tomato, Lycopersicon esculentum var. cerasiforme, which grows in the tea zones of Mount Kenya region, Kenya, is not attacked by T. absoluta, unlike the cultivated commercial tomato varieties. It was hypothesized that the wild variety may be actively avoided by gravid females because of the presence of constituents that deter gravid T. absoluta females. The objective of the present study was to compare the behavioral responses of T. absoluta to wild and cultivated tomato plants and characterize their mediating semiochemical blends. The responses of gravid T. absoluta females to the wild tomato and cultivated tomato, Solanum lycopersicum L. (Rambo F1 variety) intact plants in a dual–choice olfactometer was conducted where the gravid females were attracted to the cultivated species but repelled by the wild species, PI = -45.45%, X2 = 10.47, df = 1, p < 0.05. The levels of infestation of the pest in mono–crop and intercrops of the two varieties were also compared. There was significant reduction in the levels of infestation in the intercrop arrangements (P