Compatibility and efficacy of Metarhizium anisopliae and sex pheromone for controlling Thaumatotibia leucotreta

Abstract

A sound IPM management for false codling moth (FCM), Thaumatotibia leucotreta, a devastating pest threatening horticultural production in Africa, is urgently needed. The compatibility of the dry conidia of virulent fungal isolate, Metarhizium anisopliae ICIPE 69 with FCM sex pheromone (Crytrack®) in the autoinoculation was assessed. The effect of the pheromone on the conidial germination was monitored for 4 weeks under field conditions. The multilocation trial was implemented in Machakos and Makueni counties in Kenya to test the efficacy of M. anisopliae ICIPE 69 and Last Call FCM® for T. leucotreta control in orange orchards. The treatments evaluated were (1) M. anisopliae ICIPE 69 (Campaign® and dry conidia); (2) Last Call FCM®; (3) M. anisopliae ICIPE 69 (Campaign® and dry conidia) and Last Call FCM®; and (4) Untreated control orchards. Results show that the conidial viability is not affected by the pheromone. For the multilocation FCM control trial, all treated orchards recorded a significant reduction in the FCM population and consequently fruit infestation, relative to the control (no intervention). FCM infested fruits were 18, 27, 5, and 49% in the treatments 1, 2, 3, and 4, respectively, in Machakos, and 24, 31, 7, and 54% for treatments 1, 2, 3 and 4 in Makueni. The highest marketable yield was recorded in orchards that received treatment 3 for both counties. The yield was 10,880.68 and 11,192.26 kg orange fruit/ha for Machakos and Makueni, respectively. The implication for the management of FCM is discussed in light of the findings of this study.