Field evaluation of new synthetic pheromone lures for monitoring of false codling moth in avocado orchards

Abstract

The false codling moth (FCM) is a key quarantine pest in Africa. Agricultural exports infested by the pest are unacceptable in the international markets, causing losses of millions of US dollars in foreign exchange earnings. In Uganda and probably most African countries, inspection of agricultural exports, of which avocado is key, relies on visual observations, which seem ineffective in pest detection. An integrated pest management (IPM) approach has shown to be the only effective approach in management of this pest. However, this approach requires a strong monitoring and surveillance system. This research therefore aims at increasing Uganda’s fruit exports through adopting the use of commercially available synthetic sex pheromone lures in an IPM approach to reduce the risk of avocado rejection due to the presence of T.leucotretaby importing countries. In this study the attractiveness of different commercial synthetic sex pheromone lures to false codling moth adult males was assessed using white delta traps. To check for species specificity of the lures,PherodisSpodopterafrugiperda, lure was included. The study was conducted for eight (8) consecutive weeks in an avocado orchard at the National Agricultural Research Laboratories (NARL) Horticulture fieldKawanda, Wakiso district in central Uganda. The experimental design was a Randomized Complete Block Design (RCBD) where the field was divided into three blocks of different avocado varieties (Fuerte, Hass and Reed) and treatments were replicated three times. The treatments included PherodisThaumatotibialeucotreta, Indian T. leucotretaandPherodisSpodopterafrugiperda. Data were collected on number of male moths per lure per week and the number of other Lepidoptera species per trap. Results revealed that lure type had a significant impact on the number of moths attracted (p˂0.001). PherodisThaumatotibialeucotreta lure (5moths per week) was found to be significantly more attractive to male T.leucotreta than the Indian Thaumatotibialeucotreta lure (2moths per week). However, PherodisSpodopterafrugiperda lure which was included to test for species specificity for the lures attracted only Spodoptera frugiperda moths and no false codling moth was attracted by this lure. The control (delta trap with no lure) did not attract any moth as well. The number of moths attracted to each lure declined with time of exposure in the field in all the treatments. It was recommended that farmers should use PherodisT.leucotretalure for monitoring because it attracted the most number of male false codling moths throughout the entire period of the experiment compared to other lures in addition to a longer lifetime.