RESUMELa punaise Pseudotheraptus devastans est l'un des principaux insectes ravageurs du cocotier en Côte d'Ivoire. Les attaques de Pseudotheraptus devastans provoquent la chute des noix immatures. Les pertes de production dues à ce ravageur, de l'ordre de 80%, sont élevées. Pour évaluer l'incidence des attaques causées par Pseudotheraptus devastans, des relevés mensuels de ses attaques ont été enregistrés sur des régimes âgés de 1 à 7 mois chez les hybrides de cocotier PB 113

Pseudotheraptus devastans Distant (Heteroptera: Coreidae), is an important coconut pest in Côte d'Ivoire. The stings from Nymph and adult cause not only the falling of immature nuts, but also their deformation. This triggers losses of production in the order can reach 80%. Little information is available about this pest. Those existing are limited to its ecology and damages caused in host-plants. The present investigation is aimed to study the life cycle of this pest. The experiment was carried out in a coconut field of the Marc Delorme Coconut Research Station (MDCRS). On these coconut palms, bunches between 3 and 4 months of age, enclosed in cage were used. Development duration from an egg to adult emergence averaged 28.26 days. The average incubation period was on average 6.63 days and fertility rate of eggs was 98.01%. Nymphal development period was 21.63 days. The sex-ratio is in favour of females which live 112.6 ± 13.45 days. These females laid on average 198.85 ± 36.05 eggs. The males lived on average 131.3 ± 17.7 days. The knowledge of these different parameters could allow the development of a control method based on the breaking of life cycle of this pest.

Genetic control by creation of the coconut varieties expressing both Lethal Yellowing (LY) disease resistance and good agronomic performances led breeders to select in Tall populations which contain large diversity, some peculiar palms used as genitors. Thus, 18 genotypes of Vanuatu Tall (VTT) coded from G1 to G18 were described from 30 quantitative descriptors assessed on the coconut organs that are stem, leaf, inflorescence and fruit. The results showed that these 18 VTT genotypes were divided into two agro-morphological clusters: (i) genotypes providing large nuts with heavy components and (ii) the genotypes characterized by small fruit with weak component weights. Therefore, the genotypes that belong to first cluster G1,

En Côte d’Ivoire, le cocotier (Cocos nucifera L.) est essentiellement cultivé sur le littoral ivoirien et constitue la principale culture de rente en assurant des revenus à plus de 20 000 familles. Cependant, la plante est sujette à plusieurs contraintes dont la plus inquiétante actuellement est le jaunissement mortel du cocotier de Grand-Lahou. Ce travail vise à étudier la dynamique saisonnière des potentiels vecteurs du phytoplasme de la maladie du jaunissement mortel du cocotier à Grand-Lahou (Nedotepa curta et Proutista fritillaris). Les insectes ont été collectés avec des pièges à glu, hissés à l’aide d’une corde dans la couronne des cocotiers de deux villages de Grand-Lahou (Badadon et Yaokro), d’octobre 2015 à septembre 2016. Sur ces deux sites, les fluctuations les plus importantes des populations de N. curta et P. fritillaris ont été observées en décembre 2015 et en février 2016. L’analyse de corrélation de Pearson réalisée entre quelques facteurs abiotiques et les fluctuations des populations de ces insectes montre que la température et les fluctuations de ces insectes ne sont pas significativement corrélées. Par contre, il existe une influence hautement significative et négative (r˃-0,7 ; p˂0,0001) de la pluviométrie sur les populations de ces insectes. Une influence significative et négative (r˃-0,7 ; p˂0,005) de l’humidité relative sur ces insectes a été également observée. Les potentiels vecteurs du jaunissement mortel du cocotier de Grand-Lahou pullulent donc au cours des périodes sèches de l’année. La température n’affecte pas le développement de ces insectes alors que la pluviométrie et l’humidité relative diminue leur développement.   In Côte d’Ivoire, the coconut tree (Cocos nucifera L.) is cultivated essentially on the coastline of Côte d'Ivoire. It is one of the main cash crops that provide income to close to 20,000 families. The plant is subject to several constraints of which the most troubling one among them is the coconut lethal yellowing of Grand-Lahou. This paper focuses on the seasonal dynamics of the potentials vectors of phytoplasma of the coconut lethal yellowing of Grand-Lahou (Nedotepa curta and Proutista fritillaris). The insects were collected with traps tights, hoisted with the help of a rope in the crown of the coconut trees of two villages of Grand-Lahou (Badadon and Yaokro), from October 2015 to September 2016. On these two sites, the most important fluctuations of the populations of N. curta and P. fritillaris were observed in December 2015 and in February 2016. The realized Pearson interrelationship analysis between some abiotic factors and the fluctuations of the populations of these insects show that the temperature and the fluctuations of these insects are not correlated meaningfully. On the other hand, there is a highly meaningful and negative influence (r˃-0,7 ; p˂0,0001) of rainfall on the populations of these insects. A meaningful and negative influence (r˃-0,7 ; p˂0,005) of the relative humidity on these insects were also observed. The potentials vectors of the coconut lethal yellowing of Grand-Lahou swarm can be seen during the dry periods of the year. Although the temperature does not affect the development of these insects, the rainfall and the relative humidity decrease their development.

Aims: This study aimed to assess the impact of human activities on termites in teak plantations in the Korhogo communal area. Methodology: Termites were sampled from October to November 2020 using the transect method recommended by Jones and Eggleton (2000). The study was carried out in three teak plantations undergoing different levels of human activities, with a forest fragment as reference area. Five types of human activity were assessed and the overall proportion of human pressure on each habitat was calculated. The species richness (S), Shannon index (H'), Evenness (E) and the relative abundance were calculated of termites for each habitat type. Analyses of variance (ANOVA) were used to compare the species richness and abundance of termites. Results: The results showed that the village plantation of teak (PVT) had the highest degree of human pressure (50.94%), followed by the teak plantation of the forest of Mount Korhogo (TFMK) (29.24%). The teak plantation of Botanical Garden (TJB) was under low pressure (6.60%). A total of 30 species grouped in 19 genera and 8 sub-families of termites were identified in all plots. Termite diversity was high in the forest fragment (19.67 ± 1.15) and in the teak plantation of Botanical Garden (21.33 ± 2.08), but low in the village teak plantation (11 ± 1). The abundance of termites evolves in the same direction as the species richness. Conclusion: Anthropogenic activities affect the trophic composition of termites, particularly the humivore group. Reconstruction of the fauna and flora of the teak forests would be beneficial for the conservation of termite species. In this region, teak forests would thus play a role as a refuge for termite communities, which are recognised as the main soil fertilising organisms in the tropics.