Bio-ecology of the False Codling Moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) in the Capsicum agro-system in Selected Counties in Lower Eastern Kenya

Abstract

The False Codling Moth (FCM) [Thaumatotibia leucotreta (Meyrick), (Lepidoptera; Tortricidae)] is an economically significant insect pest that simultaneously attacks and destroys many cultivated crops, and Capsicum [Capsicum spp. (Solanales: Solanaceae)] is among the most affected. Despite this pest causing a reduction in crop yield and quality, it is also considered a quarantine pest thus it constrains international trade of vulnerable crops. Despite the menacing effects of this pest, there is scanty data on baselines of the occurrence, prevalence, damage and varietal differences in FCM preference and performance in Lower Eastern Kenya (Kitui, Machakos and Makueni). The current management strategies and perspectives of farmers toward FCM are yet to be assessed and documented. To fill this gap, a field survey was conducted between 2021- 2023, a total of 135 farmers were randomly interviewed using a structured questionnaire. From the interviewed farmers (135), a total of 75 farms were chosen (based on the availability of mature fruits) for onsite sampling. Fifty plants were randomly selected on each farm to basing on visual inspection for damage symptoms of FCM. Of 28 farms sampled in Kitui County, FCM was present in 15 farms, equivalent to 53.6 %, followed by Makueni County, 7 out of 23 farms, equivalent to 29.2% and lastly, Machakos County, 3 out of 24 farms, equivalent to 12.5%. These differences in prevalence rate were significant (F = 13.89, df = 2, 70, p< 0.05). The damage level was also significant in Kitui 25.74 ± 4.36 compared to Makueni 5.89 ± 1.34 and Machakos 4.27 ± 1.12 which were similar (F = 12.3, df = 2, 70, p < 0.001). The average infestation of FCM was significantly affected by the intercropping system in Kitui County (LR = 8.50, df = 3, 24, p = 0.036) and Machakos County (LR = 8.96, df = 3, 20, p = 0.029) but failed in Makueni (LR = 92.35, df = 3, 19, p = 0.502). The survey indicated that only 29% of farmers interviewed knew of false codling moth. Pesticides were the primary method of pest management. The study also found that FCM oviposition preference and performance were significantly (p<0.05) influenced by the Capsicum species offered to them. The highest number of eggs was laid on bell peppers, followed by bullet chillies and long chillies, while the lowest number of eggs were laid on chilli peppers both in the choice test and no choice test, respectively. These findings are beneficial in predicting the population dynamics, host preference, and providing baselines for the crafting of alternative strategies like screening for resistant varieties to mitigate the negative effects of pesticide resistance