Process of Attack on Cashew Tree Branches by Diastocera trifasciata (Coleoptera: Cerambycidae) and the Relationship between These Attacks and the Phenological Stages in the Gbêkê Region (Central Côte d’Ivoire)

Abstract

Cerambycidae Diastocera trifasciata attacks were studied from October 2015 to September 2017 in three cashew tree orchards in the locality of Brobo in central Côte d’Ivoire. One hundred fifty-three (153) cashew trees, arranged on a diagonal from each orchard, were selected for sampling. The attacked plants and the branches cut per tree were counted every 15 days. Biotic parameters, namely phenological stages of trees, and abiotic factors, which are rainfall, relative humidity and average temperature, were recorded throughout the study. Attacks were observed from mid-September to January from the pre-flowering vegetative stage to the flowering stage. Attack period duration was therefore four and a half months per year. The peak of attacks was recorded in November with an attack rate of 88.02% in 2015 and 75.49% in 2016. No attack was recorded from February to mid-September, corresponding to the flowering, fruiting and post-harvest vegetative growth stages. This description of the attack process and the determination of D. trifasciata attack periods provides essential data for the implementation of an effective and sustainable control method of this species.

Analysis of cashew tree density and its effect on damage caused by the stem borer, Apate terebrans (Coleoptera: Bostrichidae), in Côte d'Ivoire (West Africa)

“…Cashew, Anacardium occidentale L. (Anacardiaceae), is subject to pest pressure in the tropical areas of Asia and Africa where it is mainly grown (Agboton et al 2017;Ouali N'Goran et al 2020;Vanitha and Raviprasad 2022). The proliferation of these bio-aggressors occurs in a context where this crop is booming in West Africa.…”

“…Côte d'Ivoire's cashew orchards face a number of major agronomic and phytosanitary constraints (Kouakou et al 2018;Ouali N'Goran et al 2020;Soro et al 2020a), which limit yields to around 450 kg/ha compared with 1,200 kg/ha in experimental stations (Djaha et al 2010). Most of the current orchards in Côte d'Ivoire were created on the basis of 'individual' cultivation practices by farmers, without any substantial technical or financial support from the State (Ruf et al 2019).…”

Seasonal Fluctuation of The Populations of The Stem Borer, Apate terebrans (Coleoptera: Bostrichidae) in Cashew Orchards in North-Eastern Côte d'Ivoire (West Africa)

“…However, the Ivorian cashew orchard, in general, suffers from real agronomic and phytosanitary constraints (Soro et al, 2020), resulting in low yields, around 450 kg/ha compared to 1200 kg/ha in experimental stations in West Africa (Djaha et al, 2010). These include unimproved planting material (Kouakou et al, 2018), high cashew tree density (Kambou et al, 2019) and the proliferation of phytopathologies (Soro et al, 2020) and insect pests (N'Dépo et al, 2017;Ouali-N'Goran et al, 2020) Apate terebrans Pallas, an insect of tropical and arid zones (Ivie, 2002) and a forest pest in Africa (Schabel et al, 1999), is one of the main insect pests of cashew trees in West Africa (FAO, 2007;Agboton et al, 2017). Indeed, the adult digs galleries inside the woody tissues of the cashew tree, in which it feeds and lives, rejecting at the foot of the attacked tree a large quantity of sawdust.…”