Caractéristiques de l’évolution spatio-temporelle de Thaumatotibia leucotreta Meyrick (Lepidoptera : Tortricidae) dans les zones de production cotonnière de Côte d’Ivoire

Abstract

In order to update knowledge on the spatio-temporal evolution of Thaumatotibia leucotreta, the geographical areas and seasons of predilection of adult and larval populations have been studied in the last six years from 2012 to 2017. Monitoring of natural adult populations revealed that populations were more abundant in the southern cotton production area as compared to the north. A Monitoring of larval infestations showed that infestations occurred on cotton at the end of august (0.10 larvae/100 bolls) and increased gradually during october-november (0.31 to 0.93 larvae/100 bolls), indicating a strong relationship between evolution of adult and larval populations and cotton phenology. Early sowings exhibited higher infestation levels (0.87 larvae/100 bolls). Annual variations of pest infestation levels increased from years to years, from 0.23 to 0.49 larvae/100 bolls over the study period. Mapping the geographic distribution of infestations showed highest pest densities in the southern zone, mostly in surrounding areas of Boron (1.52 larvae/100 bolls). With regard to the emerging status of T. leucotreta over recent years, the current pyrethroid resistance management strategy deserves to be improved on the basis of the pest geographic and seasonal profiles.

Activity of insecticide detoxification enzymes in Pectinophora gossypiella (Saunders): Implications for insect pest management in cotton crops

“…This could reflect the strong presence of P. gossypiella in these localities. However, Ochou et al (2018) have shown in their studies the strong presence of endocarpic organisms (P. gossypiella and T. leucotreta) in the southern zone of the cotton basin, precisely in certain localities such as Bouaflé and Séguéla.…”

Efficacité des pièges à phéromones dans la gestion de Pectinophora gossypiella (Lepidoptera : Gelechiidae) et Thaumatotibia leucotreta (Lepidoptera : Tortricidae), ravageurs endocarpiques du cotonnier en Côte d’Ivoire

“…Au stade de floraison un nombre important de papillons peut être observés alors qu'à la phase de formation des organes fructifères (capsules) du cotonnier, les chenilles sont plus abondantes. Ce constat a été fait par Ochou et al (2018) qui ont montré que les papillons de P. gossypiella et T. leucotreta étaient plus abondants pendant la période de floraison qu'à la période de formation des organes fructifères du cotonnier. Il est donc difficile de prédire les infestations larvaires à partir des captures des adultes.…”

“…Aussi, le recours aux insecticides de synthèse peut mettre en danger la santé humaine et créer un désordre écologique ( Barzman et al, 2015). Les ennemis naturels sont réduits par l'action des insecticides qui peut engendrer la recrudescence de certains ravageurs; (Kone et al, 2017;Didi et al, 2018). A cela s'ajoutent les pertes de sensibilité voire la résistance des cibles suites à l'utilisation excessive des insecticides (Doffou, 2013 ;Ochou, 2019).…”

New subdivision of cotton production area of Côte d’Ivoire based on the infestation of main arthropod pests

“…Systematic monitoring has therefore been initiated to detect variations in time. In recent years, data have revealed the emergence or recrudescence of certain pests such as cotton jassids [11] , whiteflies [5] , Helicoverpa armigera, T. leucotreta, P. gossypiella [16,17] , etc. The spatiotemporal dynamics of these pests highlight major changes that can compromise the effectiveness of the protection strategy.…”